双电池方案 电源管理芯片(手机)

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FEATURES DESCRIPTION

APPLICATIONS

POWER FLOW DIAGRAM

(1)

bq24070

SLUS694A–MARCH2006–REVISED MARCH2006 SINGLE-CHIP CHARGE AND SYSTEM POWER-PATH MANAGEMENT IC

?Small3,5mm×4,5mm QFN Package The bq24070device is a highly integrated Li-ion

linear charger and system power-path management ?Designed for Single-Cell Li-Ion-or

device targeted at space-limited portable Li-Polymer-Based Portable Applications

applications.The bq24070offers DC supply(AC ?Integrated Dynamic Power-Path Management

adapter)power-path management with autonomous (DPPM)Feature Allowing the AC Adapter to power-source selection,power FETs and current Simultaneously Power the System and sensors,high-accuracy current and voltage Charge the Battery regulation,charge status,and charge termination,in

a single monolithic device.

?Power Supplement Mode Allows Battery to

Supplement the AC Input Current The bq24070powers the system while independently ?Autonomous Power Source Selection(AC charging the battery.This feature reduces the charge Adapter or BAT)and discharge cycles on the battery,allows for

proper charge termination and allows the system to ?Supports Up to2-A Total Current

run with an absent or defective battery pack.This ?Thermal Regulation for Charge Control feature also allows for the system to instantaneously

?Charge Status Outputs for LED or System turn on from an external power source in the case of

a deeply discharged battery pack.The IC design is

Interface Indicates Charge and Fault

focused on supplying continuous power to the Conditions

system when available from the AC adapter or ?Reverse Current,Short-Circuit,and Thermal

battery sources.

Protection

?Power Good Status Outputs

?Smart Phones and PDA

?MP3Players

?Digital Cameras and Handheld Devices

?Internet Appliances

(1)See Figure2and functional block diagram for more detailed feature information.

(2)P-FET back gate body diodes are disconnected to prevent body diode conduction.

Please be aware that an important notice concerning availability,standard warranty,and use in critical applications of Texas

Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

PRODUCTION DATA information is current as of publication date.Copyright?2006,Texas Instruments Incorporated Products conform to specifications per the terms of the Texas

Instruments standard warranty.Production processing does not

necessarily include testing of all parameters.

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SLUS694A–MARCH2006–REVISED MARCH2006

These devices have limited built-in ESD protection.The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOSFET gates.

The MODE pin selects the priority of the input sources.If an input source is not available,then the battery is selected as the source.With the MODE pin high,the bq24070attempts to charge from the input at the charge rate set by ISET1pin.With the MODE pin low,the bq24070defaults to USB charging at the charge rate.This feature allows the use of a single connector(mini-USB cable),where the host programs the MODE pin according to the source that is connected(AC adaptor or USB port).Table1summarizes the MODE pin function.

Table1.Power Source Selection Function Summary

MODE STATE AC MAXIMUM SYSTEM USB BOOT-UP

ADAPTER CHARGE RATE(1)POWER FEATURE

SOURCE Low Present ISET2USB Enabled

Absent N/A Battery Disabled High Present ISET1AC Disabled

Absent N/A Battery Disabled (1)Battery charge rate is always set by ISET1,but may be reduced by a limited input source(ISET2USB mode)and I OUT system load.

ORDERING INFORMATION(1)

BATTERY PART PACKAGE T A OUT PIN STATUS

VOLTAGE(V)NUMBER(2)(3)MARKING

4.2Regulated to4.4V(4)bq24070RHLR Production BRQ

–40°C to125°C

4.2Regulated to4.4V(4)bq24070RHLT Production BRQ

(1)For the most current package and ordering information,see the Package Option Addendum at the end of this document,or see the TI

Web site at https://www.doczj.com/doc/3011762318.html,.

(2)The RHL package is available in the following options:

R-taped and reeled in quantities of3,000devices per reel.

T-taped and reeled in quantities of250devices per reel.

(3)This product is RoHS compatible,including a lead concentration that does not exceed0.1%of total product weight,and is suitable for

use in specified lead-free soldering processes.In addition,this product uses package materials that do not contain halogens,including bromine(Br)or antimony(Sb)above0.1%of total product weight.

(4)If AC

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ABSOLUTE MAXIMUM RATINGS(1)

RECOMMENDED OPERATING CONDITIONS DISSIPATION RATINGS

bq24070 SLUS694A–MARCH2006–REVISED MARCH2006

over operating free-air temperature range(unless otherwise noted)

bq24070

Input voltage IN(DC voltage wrt(with respect to)VSS)–0.3V to18V

BAT,CE,DPPM,PG,Mode,OUT,ISET1,ISET2,STAT1,

–0.3V to7V

STAT2,TS,(all DC voltages wrt VSS)

Input voltage

V REF(DC voltage wrt VSS)–0.3V to V O(OUT)+0.3V

TMR–0.3V to V O+0.3V

Input current 3.5A

OUT4A

Output current

BAT(2)–4A to3.5A

Output sink current PG,STAT1,STAT2, 1.5mA

Storage temperature range,T stg–65°C to150°C

Junction temperature range,T J–40°C to150°C

Lead temperature(soldering,10seconds)300°C

(1)Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device.These are stress ratings

only,and functional operation of the device at these or any other conditions beyond those indicated under recommended operating conditions is not implied.Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.All voltage values are with respect to the network ground terminal unless otherwise noted.

(2)Negative current is defined as current flowing into the BAT pin.

MIN MAX UNIT V CC Supply voltage(V IN)(1) 4.3516V

I AC Input current2A

T J Operating junction temperature range–40125°C (1)Verify that power dissipation and junction temperatures are within limits at maximum V CC.

T A≤40°C DERATING FACTOR

PACKAGEθJA

POWER RATING T A>40°C

20-pin RHL(1) 1.81W21mW/°C46.87°C/W

(1)This data is based on using the JEDEC High-K board and the exposed die pad is connected to a Cu pad on the board.This is

connected to the ground plane by a2×3via matrix.

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PARAMETER

TEST CONDITIONS MIN TYP MAX UNIT INPUT BIAS CURRENTS

I CC(SPLY)

Active supply current,VCC V VCC >V VCC(min)12mA V IN

Excludes load on OUT pin V I(AC)≤6V,Total current into IN pin with I CC(IN-STDBY)Input standby current chip disabled,Excludes all loads,

200CE=LOW,after t (CE-HOLDOFF)delay

μA Total current into BAT pin with input

present and chip disabled;

I CC(BAT-STDBY)BAT standby current Excludes all loads,CE=LOW,

4565after t (CE-HOLDOFF)delay,

0°C ≤T J ≤85°C

I IB(BAT)Charge done current,BAT

Charge DONE,input supplying the load 15OUT PIN-VOLTAGE REGULATION Output regulation

V O(OUT-REG)V I(AC)≥4.4V+V DO 4.4 4.5V voltage

OUT PIN –DPPM REGULATION V (DPPM-SET)DPPM set point (1)

V DPPM-SET

Input present 95100105μA SF DPPM scale factor V (DPPM-REG)=V (DPPM-SET)×SF

1.139 1.150 1.162OUT PIN –FET (Q1,Q2)DROP-OUT VOLTAGE ?DS(on))V I(AC)≥V CC(min),Mode =High,

V (ACDO)AC to OUT dropout voltage (2)300475I I(AC)=1A,(I O(OUT)+I O(BAT)),or no input

mV BAT to OUT dropout voltage V (BATDO)V I (BAT)≥3V,I i(BAT)=1.0A,V CC

OUT PIN -BATTERY SUPPLEMENT MODE Enter battery supplement mode

V I(OUT)V BSUP1(battery supplements OUT current

V I(BAT)>2V ≤V I(BAT)in the presence of input source

–60mV V V I(OUT)V BSUP2Exit battery supplement mode V I(BAT)>2V

≥V I(BAT)–20mV OUT PIN -SHORT CIRCUIT

Current source between BAT to OUT for I OSH1

BAT to OUT short-circuit recovery short-circuit recovery to 10mA V I(OUT)≤V I(BAT)–200mV R SHAC AC to OUT short-circuit limit

V I(OUT)≤1V 500?BAT PIN CHARGING –PRECHARGE Precharge to fast-charge transition

V (LOWV)Voltage on BAT 2.93 3.1V threshold

Deglitch time for fast-charge to

t FALL =100ns,10mV overdrive,T DGL(F)22.5ms precharge transition (3)

V I(BAT)decreasing below threshold 1V

10150mA I O(PRECHG)=(K (SET)×V (PRECHG))/R SET V (PRECHG)Precharge set voltage 1V

225250275mV BAT PIN CHARGING -CURRENT REGULATION V i (BAT)>V (LOWV),Mode =High

I O(BAT)Battery charge current range (4)I OUT(BAT)=(K (SET)×V (SET)/R SET ),

10010001500mA V I (OUT)>V O (OUT-REG)+V (DO-MAX)

R PBAT BAT to OUT pullup V i (BAT)<1V

1000?(1)

V (DPPM-SET)is scaled up by the scale factor for controlling the output voltage V (DPPM-REG).(2)

V DO(max),dropout voltage is a function of the FET,R DS(on),and drain current.The dropout voltage increases proportionally to the increase in current.(3)

All deglitch periods are a function of the timer setting and is modified in DPPM or thermal regulation modes by the percentages that the program current is reduced.(4)

When input current remains below 2A,the battery charging current may be raised until the thermal regulation limits the charge current.4Submit Documentation Feedback

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bq24070 SLUS694A–MARCH2006–REVISED MARCH2006

ELECTRICAL CHARACTERISTICS(continued)

over junction temperature range(0°C≤T J≤125°C)and the recommended supply voltage range(unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

Voltage on ISET1,V VCC≥4.35V,

Battery charge current set

V(SET)V I(OUT)-V I(BAT)>V(DO-MAX), 2.47 2.50 2.53V voltage(5)

V I(BAT)>V(LOWV)

100mA≤I O(BAT)≤1.5A375425450

K(SET)Charge current set factor,BAT

10mA≤I O(BAT)≤100mA(6)300450600

USB MODE INPUT CURRENT LIMIT

ISET2=Low8090100

I(USB)USB input port current range mA

ISET2=High400500

BAT PIN CHARGING VOLTAGE REGULATION,V O(BAT-REG)+V(DO-MAX)

Battery charge voltage 4.2V

V O(BAT-REG)T A=25°C–0.5%0.5% Battery charge voltage regulation

accuracy–1%1%

CHARGE TERMINATION DETECTION

Charge termination detection V I(BAT)>V(RCH),

I(TERM)10150mA range I(TERM)=(K(SET)×V(TERM))/R SET

V I(BAT)>V(RCH),Mode=High230250270 Charge termination set voltage,

V(TERM)mV measured on ISET1V

I(BAT)

>V(RCH),Mode=Low95100130

t FALL=100ns,10mV overdrive,

Deglitch time for termination

T DGL(TERM)I CHG increasing above or decreasing22.5ms detection

below threshold

TEMPERATURE SENSE COMPARATORS

V LTF High voltage threshold Temp fault at V(TS)>V LTF 2.465 2.500 2.535V

V HTF Low voltage threshold Temp fault at V(TS)

I TS Temperature sense current source94100106μA

R(TMR)=50k?,V I(BAT)increasing or

Deglitch time for temperature fault

T DGL(TF)decreasing above and below;22.5ms detection(7)

100-ns fall time,10-mv overdrive

BATTERY RECHARGE THRESHOLD

V O(BAT-REG)V O(BAT-REG)V O(BAT-REG)

V RCH Recharge threshold voltage V

–0.075–0.100–0.125

R(TMR)=50k?,V I(BAT)increasing

Deglitch time for recharge

T DGL(RCH)or decreasing below threshold,22.5ms detection(7)

100-ns fall time,10-mv overdrive

STAT1,STAT2,AND PG,OPEN DRAIN(OD)OUTPUTS(8)

I OL=5mA,An external pullup

V OL Low-level output saturation voltage0.25V

resistor≥1K required.

I LKG Input leakage current15μA ISET2,CE INPUTS

V IL Low-level input voltage00.4

V

V IH High-level input voltage 1.4

I IL Low-level input current,CE–1

I IH High-level input current,CE1

μA

I IL Low-level input current,ISET2V ISET2=0.4V–20

I IH High-level input current,ISET2V ISET2=V CC40

t(CE-HLDOFF)Holdoff time,CE CE going low only46ms MODE INPUT

Falling Hi→Low;280K±10%applied

V IL Low-level input voltage0.9751 1.025V

when low.

V IH High-level input voltage Input R Mode sets external hysteresis V IL+.01V IL+.024V

I IL Low-level input current,Mode–1μA

(5)For half-charge rate,V(SET)is1.25V±25mV.

(6)Specification is for monitoring charge current via the ISET1pin during voltage regulation mode,not for a reduced fast-charge level.

(7)All deglitch periods are a function of the timer setting and is modified in DPPM or thermal regulation modes by the percentages that the

program current is reduced.

(8)See Charger Sleep mode for PG(V CC=V IN)specifications.

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over junction temperature range (0°C ≤T J ≤125°C)and the recommended supply voltage range (unless otherwise noted)

PARAMETER

TEST CONDITIONS MIN TYP MAX UNIT TIMERS

K (TMR)

Timer set factor t (CHG)=K (TMR)×R (TMR)0.3130.3600.414s/?R (TMR)(9)

External resistor limits 30100k ?t (PRECHG)

Precharge timer 0.09×t (CHG)0.10×t (CHG)0.11×t (CHG)s Timer fault recovery pullup from I (FAULT)1k ?OUT to BAT CHARGER SLEEP THRESHOLDS (PG THRESHOLDS,LOW →POWER GOOD)

V VCC ≤V (UVLO)≤V I(BAT)≤V O(BAT-REG),

V (SLPENT)(10)Sleep-mode entry threshold V I(BAT)No t (BOOT-UP)delay

+125mV V V VCC ≥V (UVLO)≤V I(BAT)≤V O(BAT-REG),

V (SLPEXIT)(10)Sleep-mode exit threshold V I(BAT)No t (BOOT-UP)delay

+190mV R (TMR)=50k ?,

t (DEGL)Deglitch time for sleep mode (11)V (IN)decreasing below threshold,100-ns

22.5ms fall time,10-mv overdrive

START-UP CONTROL BOOT-UP On the first application of input with

t (BOOT-UP)Boot-up time 120150180ms Mode Low

SWITCHING POWER SOURCE TIMING When input applied.Measure from:

Switching power source from input [PG:Lo →Hi to I (IN)>5mA],

t SW-BAT 50μs to battery I (OUT)=100mA,

R TRM =50K

THERMAL SHUTDOWN REGULATION (12)T (SHTDWN)Temperature trip T J (Q1and Q3only)

155Thermal hysteresis T J (Q1and Q3only)

30°C T J(REG)Temperature regulation limit

T J (Q2)

115135UVLO V (UVLO)Undervoltage lockout Decreasing V CC 2.45 2.50

2.65V Hysteresis 27mV (9)To disable the safety timer and charge termination,tie TMR to the V REF pin.

(10)The IC is considered in sleep mode when IN is absent (PG =OPEN DRAIN).

(11)Does not declare sleep mode until after the deglitch time and implement the needed power transfer immediately according to the

switching specification.

(12)Reaching thermal regulation reduces the charging current.Battery supplement current is not restricted by either thermal regulation or

shutdown.Input power FETs turn off during thermal shutdown.The battery FET is only protected by a short-circuit limit which typically does not cause a thermal shutdown (input FETs turning off)by itself.

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DEVICE INFORMATION

STAT2

IN

BA T

BA T ISET2 MODE

CE

bq24070RHL

RHL P ACKAGE

(T OP VIEW)

PG

OUT

OUT

OUT

TMR

DPPM

TS

N

D

R

E

F

V

S

S

I

S

E

T

STAT1GND

bq24070 SLUS694A–MARCH2006–REVISED MARCH2006

TERMINAL FUNCTIONS

TERMINAL

I/O DESCRIPTION

NAME NO.

IN4I Charge input voltage

PG18O Power-good status output(open-drain)

BAT5,6I/O Battery input and output.

CE9I Chip enable input(active high)

DPPM13I Dynamic power-path management set point(account for scale factor)

ISET110I/O Charge current set point and precharge and termination set point

Charge current set point for USB port.(High=500mA,Low=100mA)For bq24070,see half-charge ISET27I

current mode using ISET2.

OUT15,16,17O Output terminal to the system

MODE8I Power source selection input(Low for USB mode current limit)

STAT12O Charge status output1(open-drain)

STAT23O Charge status output2(open-drain)

TMR14I/O Timer program input programmed by resistor.Disable safety timer and termination by tying TMR to V REF. TS12I/O Temperature sense input

GND19,20I Ground input

VREF1O Internal reference signal

Ground input(the thermal pad on the underside of the package)There is an internal electrical connection

between the exposed thermal pad and VSS pin of the device.The exposed thermal pad must be

VSS11–

connected to the same potential as the VSS pin on the printed-circuit board.Do not use the thermal pad

as the primary ground input for the device.VSS pin must be connected to ground at all times.

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IN ISET2

ST A T1ST A T2VSS

TS

DPPM ISET1

BA T GND CE

PG GND ?04084

TMR

OUT V REF

bq24070

SLUS694A–MARCH 2006–REVISED MARCH 2006FUNCTIONAL BLOCK DIAGRAM

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CHARGE

CONTROL

Pre-Conditioning

Regulation

Voltage

Regulation

Current Minimum

Charge

Voltage Pre?

Conditioning

and Term

Detect UDG?04087

bq24070SLUS694A–MARCH 2006–REVISED MARCH 2006

The bq24070supports a precision Li-ion or Li-polymer charging system suitable for single-cell portable devices.See a typical charge profile,application circuit,and an operational flow chart in Figure 1through Figure 3,respectively.

Figure 1.Charge Profile

9

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UDG ?04083

Control and

Status Signals bq24070

bq24070

SLUS694A–MARCH 2006–REVISED MARCH 2006FUNCTIONAL DESCRIPTIONS (continued)

Figure 2.Typical Application Circuit

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bq24070

SLUS694A–MARCH2006–REVISED MARCH2006 FUNCTIONAL DESCRIPTIONS(continued)

Figure3.Charge Control Operational Flow Chart

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Autonomous Power Source Selection,Mode Control Pin

Boot-Up Sequence

Power-Path Management

Case 1:AC Mode (Mode =High)bq24070SLUS694A–MARCH 2006–REVISED MARCH 2006FUNCTIONAL DESCRIPTIONS (continued)

With the MODE input low,the bq24070defaults to USB-mode charging,and the supply current is limited by the ISET2pin (100mA for ISET2=Low,500mA for ISET2=High).If an input source is not available,then the battery is selected as the source.

In order to facilitate the system start-up and USB enumeration,the bq24070offers a proprietary boot-up sequence.On the first application of power to the bq24070,this feature enables the 100-mA USB charge rate for a period of approximately 150ms,(t (BOOT-UP)),ignoring the ISET2and CE inputs setting.At the end of this period,the bq24070implements CE and ISET2inputs settings.Table 1indicates when this feature is enabled.See Figure 8.

The bq24070powers the system while independently charging the battery.This features reduces the charge and discharge cycles on the battery,allows for proper charge termination,and allows the system to run with an absent or defective battery pack.This feature gives the system priority on input power,allowing the system to power up with a deeply discharged battery pack.This feature works as follows.

Figure 4.Power-Path Management

System Power

In this case,the system load is powered directly from the AC adapter through the internal transistor Q1(see Figure 4).The output is regulated at 4.4V.If the system load exceeds the capacity of the supply,the output down to the battery's voltage.

Charge Control

When in AC mode the battery is charged through switch Q2based on the charge rate set on the ISET1input.Dynamic Power-Path Management (DPPM)

This feature monitors the output voltage (system voltage)for input power loss due to brown outs,current limiting,or removal of the input supply.If the voltage on the OUT pin drops to a preset value,V (DPPM)×SF,due to a limited amount of input current,then the battery charging current is reduced until the output voltage stops dropping.The DPPM control tries to reach a steady-state condition where the system gets its needed current and the battery is charged with the remaining current.No active control limits the current to the system;therefore,if the system demands more current than the input can provide,the output voltage drops just below the battery voltage and Q2turns on which supplements the input current to the system.DPPM has three main advantages.

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(1)

Case 2:USB Mode (Mode =L)bq24070SLUS694A–MARCH 2006–REVISED MARCH 2006

FUNCTIONAL DESCRIPTIONS (continued)

1.This feature allows the designer to select a lower power wall adapter,if the average system load is

moderate compared to its peak power.For example,if the peak system load is 1.75A,average system load is 0.5A and battery fast-charge current is 1.25A,the total peak demand could be 3A.With DPPM,a 2-A adaptor could be selected instead of a 3.25-A supply.During the system peak load of 1.75A and charge load of 1.25A,the smaller adaptor’s voltage drops until the output voltage reaches the DPPM regulation voltage threshold.The charge current is reduced until there is no further drop on the output voltage.The system gets its 1.75-A charge and the battery charge current is reduced from 1.25A to 0.25A.When the peak system load drops to 0.5A,the charge current returns to 1A and the output voltage returns to its normal value.

https://www.doczj.com/doc/3011762318.html,ing DPPM provides a power savings compared to configurations without DPPM.Without DPPM,if the

system current plus charge current exceed the supply’s current limit,then the output is pulled down to the battery.Linear chargers dissipate the unused power (V IN -V OUT )×I LOAD .The current remains high (at current limit)and the voltage drop is large for maximum power dissipation.With DPPM,the voltage drop is less (V IN -V (DPPM-REG))to the system which means better efficiency.The efficiency for charging the battery is the same for both cases.The advantages include less power dissipation,lower system temperature,and better overall efficiency.

3.The DPPM sustains the system voltage no matter what causes it to drop,if at all possible.It does this by

reducing the noncritical charging load while maintaining the maximum power output of the adaptor.

Note that the DPPM voltage,V (DPPM),is programmed as follows:

where

R (DPPM)is the external resistor connected between the DPPM and VSS pins.

I (DPPM)is the internal current source.

SF is the scale factor as specified in the specification table.

The safety timer is dynamically adjusted while in DPPM mode.The voltage on the ISET1pin is directly proportional to the programmed charging current.When the programmed charging current is reduced,due to DPPM,the ISET1and TMR voltages are reduced and the timer’s clock is proportionally slowed,extending the safety time.In normal operation V(TMR)=2.5V;and,when the clock is slowed,V(TMR)is reduced.When V(TMR)=1.25V,the safety timer has a value close to 2times the normal operation timer value.See Figure 5through Figure 6.

System Power

In this case,the system load is powered from a USB port through the internal switch Q1(see Figure 4).Note that in this case,Q1regulates the total current to the 100-mA or 500-mA level,as selected on input.The output,V OUT ,is regulated to 4.4V.The system's power management is responsible for keeping its system load below the USB current level selected (if the battery is critically low or missing).Otherwise,the output drops to the battey voltage;therefore,the system should have a low-power mode for USB power application.The DPPM feature keeps the output from dropping below its programmed threshold,due to the battery charging current,by reducing the charging current.

Charge Control

When in USB mode,Q1regulates the input current to the value selected by the ISET2pin (0.1/0.5A).The charge current to the battery is set by the ISET1resistor (typically >0.5A).Because the charge current typically is programmed for more current than the USB current limit allows,the output voltage drops to the battery voltage or DPPM voltage,whichever is higher.If the DPPM threshold is reached first,the charge current is reduced until V OUT stops dropping.If V OUT drops to the battery voltage,the battery is able to supplement the input current to the system.13

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V (DPPM?REG)+I (DPPM) R (DPPM) SF

(2)

Feature Plots

T = 4.26 V , DPPM Mode

Reg. @ 4.4 V (bq24070)V O U T

V A C

I C H G

I O U T

O U T D P P M ?O U V OUT ≈V ,OUT BAT Supplement Mode bq24070SLUS694A–MARCH 2006–REVISED MARCH 2006FUNCTIONAL DESCRIPTIONS (continued)

Dynamic Power-Path Management (DPPM)

The theory of operation is the same as described in CASE 1,except that Q1is restricted to the USB current level selected by the ISET2pin.

Note that the DPPM voltage,V (DPPM),is programmed as follows:

where

R (DPPM)is the external resistor connected between the DPPM and VSS pins.

I (DPPM)is the internal current source.

SF is the scale factor as specified in the specification table.

Figure 5illustrates DPPM and battery supplement modes as the output current (I OUT )is increased;channel 1=5.4V;channel 2(CH2)V OUT ;channel 3(CH3)I OUT =0to 2.2A to 0A;channel 4(CH4)V BAT =

3.5V;I (PGM-CHG)=1A.In typical operation,bq24070(V OUT =

4.4V reg ),through an AC adaptor overload condition and recovery.The AC input is set for ~

5.1V (1.5A current limit),I (CHG)=1A,V (DPPM-SET)=3.7V,V (DPPM-OUT)=

1.15×V (DPPM-SET)=4.26V,V BAT =3.5V,Mode =H,and USB input is not connected.The output load is increased from 0A to ~

2.2A and back to 0A as shown in the bottom waveform.As the I OUT load reaches 0.5A,along with the 1-A charge current,the adaptor starts to current limit,the output voltage drops to the DPPM-OUT threshold of 4.26V.This is DPPM mode.The AC input tracks the output voltage by the dropout voltage of the AC FET.The battery charge current is then adjusted back as necessary to keep the output voltage from falling any further.Once the output load current exceeds the input current,the battery has to supplement the excess current and the output voltage falls just below the battery voltage by the dropout voltage of the battery FET.This is the battery supplement mode.When the output load current is reduced,the operation described is reversed as shown.If the DPPM-OUT voltage was set below the battery voltage,during input current limiting,the output falls directly to the battery's voltage.

Under USB operation,when the loads exceeds the programmed input current thresholds a similar pattern is observed.If the output load exceeds the available USB current,the output instantly goes into the battery supplement mode.Figure 5.DPPM and Battery Supplement Modes

Figure 6illustrates when Mode is toggled low for 500μs.Power transfers from AC to USB to AC;channel 114Submit Documentation Feedback

https://www.doczj.com/doc/3011762318.html, V AC

V USB

V OUT

V BAT Break Before Make

System Capacitance Powering System USB is Charging System Capacitance

DPPM Mode

Hi

Low PSEL bq24070SLUS694A–MARCH 2006–REVISED MARCH 2006

FUNCTIONAL DESCRIPTIONS (continued)

(CH1)VAC =5.4V;channel 2(CH2)V (USB)=5V;channel 3(CH3)V OUT ;output current,I OUT =0.25A;channel 4(CH4)V BAT =3.5V;and I (PGM-CHG)=1A.When the Mode went low (1st div),the AC FET opened,and the output fell until the USB FET turned on.Turning off the active source before turning on the replacement source is referred to as break-before-make switching.The rate of discharge on the output is a function of system capacitance and load.Note the cable IR drop in the AC and USB inputs when they are under load.At the 4th division,the output has reached steady-state operation at the DPPM voltage level (charge current has been reduced due to the limited USB input current).At the 6th division,the Mode goes high and the USB FET turns off followed by the AC FET turning on.The output returns to its regulated value,and the battery returns to its programmed current level.

Figure 6.Toggle Mode Low

Figure 7illustrates when a battery is inserted for power up;channel 1(CH1)VAC =0V;channel 2(CH2)V USB =3(CH3)V OUT ;output current,I OUT =0.25A for V OUT >2V;channel 4(CH4)V BAT =3.5V;C (DPPM)=0pF.When there are no power sources and the battery is inserted,the output tracks the battery voltage if there is no load (<10mA of load)on the output,as shown.If a load is present that keeps the output more than 200mV below the battery,a short-circuit condition is declared.At this time,the load has to be removed to recover.A capacitor can be placed on the DPPM pin to delay implementing the short-circuit mode and get unrestricted (not limited)current.

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V BAT

V OUT V AC I U S B

Battery Temperature Monitoring bq24070SLUS694A–MARCH 2006–REVISED MARCH 2006FUNCTIONAL DESCRIPTIONS (continued)

Figure 7.Insert Battery –Power-Up Output via BAT

Figure 8illustrates USB boot up and power-up via USB;channel 1(CH1)V (USH)=0to 5V;channel 2(CH2)current (0.2A/div);Mode =Low;CE =High;ISET2=High;V BAT =3.85V;V (DPPM)=3.0V (V (DPPM)×

1.15

Figure https://www.doczj.com/doc/3011762318.html,B Boot-Up Power-Up

The bq24070continuously monitors battery temperature by measuring the voltage between the TS and VSS 16Submit Documentation Feedback

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Battery Pre-Conditioning

I O(PRECHG)+V(PRECHG)K(SET)

R SET(3)

Battery Charge Current

I O(OUT)+V(SET)K(SET)

R SET(4)

bq24070

SLUS694A–MARCH2006–REVISED MARCH2006 FUNCTIONAL DESCRIPTIONS(continued)

pins.An internal current source provides the bias for most-common10k?negative-temperature coefficient thermistors(NTC)(see Figure9).The device compares the voltage on the TS pin against the internal V(LTF)and V(HTF)thresholds to charging is allowed.Once a temperature outside the V(LTF)and V(HTF)thresholds is detected,the device immediately suspends the charge.The device suspends charge by turning off the power FET and holding the timer value(i.e.,timers are not reset).Charge is resumed when the temperature returns to the normal range.The allowed temperature range for103AT-type thermistor is0°C to45°C.However,the user may increase the range by adding two external resistors.See Figure10.

Figure9.TS Pin Configuration Figure10.TS Pin Thresholds

During a charge cycle,if the battery voltage is below the V(LOWV)threshold,the bq24070applies a precharge current,I O(PRECHG),to the battery.This feature revives deeply discharged cells.The resistor connected between the ISET1and VSS,R SET,determines the precharge rate.The V(PRECHG)and K(SET)parameters are specified in the specifications table.Note that this applies to both AC-mode and USB-mode charging.

The bq24070activates a safety timer,t(PRECHG),during the conditioning phase.If V(LOWV)threshold is not reached within the timer period,the bq24070turns off the charger and enunciates FAULT on the STAT1and STAT2pins.The timeout is extended if the charge current is reduced by DPPM or thermal regulation.See the Timer Fault Recovery section for additional details.

The bq24070offers on-chip current regulation with programmable set point.The resistor connected between the ISET1and VSS,R SET,determines the charge level.The charge level may be reduced to give the system priority on input current(see DPPM).The V(SET)and K(SET)parameters are specified in the specifications table.

When powered from a USB port,the input current available(0.1A/0.5A)is typically less than the programmed (ISET1)charging current,and therefore,the DPPM feature attempts to keep the output from being pulled down by reducing the charging current.

The charge level,during AC mode operation only(Mode=High),can be changed by a factor of2by setting the ISET2pin high(full charge)or low(half charge).The voltage on the ISET1pin,VSET1,is divided by2when in the half constant current charge mode.Note that with Mode low,the ISET2pin controls only the0.1A/0.5A USB current level.

See the section titled Power-Path Management for additional details.

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Temperature Regulation and Thermal Protection

Charge Timer Operation

t(CHG)+K(TMR)R(TMR)

(5)

t(CHG?TREG)+t(CHG)V(SET)

V(SET*REG)

(6)

bq24070

SLUS694A–MARCH2006–REVISED MARCH2006

FUNCTIONAL DESCRIPTIONS(continued)

The voltage regulation feedback is through the BAT pin.This input is tied directly to the positive side of the battery pack.The bq24070monitors the battery-pack voltage between the BAT and VSS pins.When the battery voltage rises to the V O(REG)threshold,the voltage regulation phase begins and the charging current begins to taper down.

If the battery is absent,the BAT pin cycles between charge done(V O(REG))and charging(battery recharge threshold,~4.1V).

See Figure7for power up by battery insertion.

As a safety backup,the bq24070also monitors the charge time in the charge mode.If charge is not terminated within this time period,t(CHG),the bq24070turns off the charger and enunciates FAULT on the STAT1and STAT2pins.See the DPPM operation under Case1for information on extending the safety timer during DPPM operation.See the Timer Fault Recovery section for additional details.

In order to maximize charge rate,the bq24070features a junction temperature regulation loop.If the power dissipation of the IC results in a junction temperature greater than the T J(REG)threshold,the bq24070throttles back on the charge current in order to maintain a junction temperature around the T J(REG)threshold.To avoid false termination,the termination detect function is disabled while in this mode.

The bq24070also monitors the junction temperature,T J,of the die and disconnects the OUT pin from the IN input if T J exceeds T(SHTDWN).This operation continues until T J falls below T(SHTDWN)by the hysteresis level specified in the specification table.

The battery supplement mode has no thermal protection.The Q2FET continues to connect the battery to the output(system),if input power is not sufficient;however,a short-circuit protection circuit limits the battery discharge current such that the maximum power dissipation of the part is not exceeded under typical design conditions.

As a safety backup,the bq24070monitors the charge time in the charge mode.If the termination threshold is not detected within the time period,t(CHG),the bq24070turns off the charger and enunciates FAULT on the STAT1and STAT2pins.The resistor connected between the TMR and VSS,R TMR,determines the timer period. The K(TMR)parameter is specified in the specifications table.In order to disable the charge timer,eliminate R TMR, connect the TMR pin directly to the V REF pin.Note that this action eliminates all safety timers,and also clears any timer fault.TMR pin should not be left floating.

While in the thermal regulation mode or DPPM mode,the bq24070dynamically adjusts the timer period in order to provide the additional time needed to fully charge the battery.This proprietary feature is designed to prevent against early or false termination.The maximum charge time in this mode,t(CHG-TREG),is calculated by Equation6.

Note that because this adjustment is dynamic and changes as the ambient temperature changes and the charge level changes,the timer clock is adjusted.It is difficult to estimate a total safety time without integrating the above equation over the charge cycle.Therefore,understanding the theory that the safety time is adjusted inversely proportionately with the charge current and the battery is a current-hour rating,the safety time dynamically adjusts appropriately.

The V(SET)parameter is specified in the specifications table.V(SET-TREG)is the voltage on the ISET pin during the thermal regulation or DPPM mode and is a function of charge current.(Note that charge current is dynamically adjusted during the thermal regulation or DPPM mode.)

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V(SET?TREG)+I(OUT)R(SET)

K(SET)

(7)

Charge Termination and Recharge

I(TERM)+V(TERM)K(SET)

R SET(8)

Sleep and Standby Modes Charge Status Outputs

PG,Outputs(Power Good) CE Input(Chip Enable)

bq24070

SLUS694A–MARCH2006–REVISED MARCH2006 FUNCTIONAL DESCRIPTIONS(continued)

All deglitch times also adjusted proportionally to t(CHG-TREG).

The bq24070monitors the voltage on the ISET1pin,during voltage regulation,to determine when termination should occur?/10–250mV).Once the termination threshold,I(TERM),is detected the bq24070terminates charge.The resistor connected between the ISET1and VSS,R SET,programs the fast charge current level?level,V ISET1= 2.5V)and thus the C/10and C/25current termination threshold level.The V(TERM)and K(SET)parameters are specified in the specifications table.Note that this applies to both AC and USB charging. After charge termination,the bq24070re-starts the charge once the voltage on the BAT pin falls below the V(RCH) threshold.This feature keeps the battery at full capacity at all times.

The bq24070charger circuitry enters the low-power sleep mode if the input is removed from the circuit.This feature prevents draining the battery into the bq24070during the absence of input supply.Note that in sleep mode,Q2remains on(i.e.,battery connected to the OUT pin)in order for the battery to continue supplying power to the system.

The bq24070enters the low-power standby mode if while input power is present,the CE input is low.In this suspend mode,internal power FET Q1(see Figure4)is turned off,the BAT input is used to power the system through the OUT pin.This feature is the power drawn from the input supply(such as USB suspend mode).

The open-drain(OD)STAT1and STAT2outputs indicate various charger operations as shown in Table2. These status pins can be used to drive LEDs or communicate to the host processor.Note that OFF

open-drain transistor is turned off.Note that this assumes CE=High.

Table2.Status Pins Summary

CHARGE STATE STAT1STAT2

Precharge in progress ON ON

Fast charge in progress ON OFF

Charge done OFF ON

Charge suspend(temperature),timer fault,and sleep mode OFF OFF

The open-drain pin,PG,indicates when input power is present,and above the battery voltage.The corresponding output turns ON(low)when exiting sleep mode(input voltage above battery voltage).This output is turned off in the sleep mode(open drain).The PG pin can be used to drive an LED or communicate to the host processor.Note that OFF indicates the open-drain transistor is turned off.

The CE(chip enable)digital input is used to disable or enable the IC.A high-level signal on this pin enables the chip,and a low-level signal disables the device and initiates the standby mode.The bq24070enters the low-power standby mode when the CE input is low with input present.In this suspend mode,internal power FET Q1(see block diagram)is turned off;the battery(BAT pin)is used to power the system via Q2and the OUT pin. This feature is designed to limit the power drawn from the input supply(such as USB suspend mode).

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Timer Fault Recovery

Short-Circuit Recovery

V REF bq24070SLUS694A–MARCH 2006–REVISED MARCH 2006The DPPM input can be used to disable the charge process.This can be accomplished by floating the DPPM pin.

As shown in Figure 3,bq24070provides a recovery method to deal with timer fault conditions.The following summarizes Condition 1:Charge voltage above recharge threshold (V (RCH))and timeout fault occurs.

Recovery Method:bq24070waits for the battery voltage to fall below the recharge threshold.This could happen as a result of a load on the battery,self-discharge,or battery removal.Once the battery falls below the recharge threshold,the bq24070clears the fault and starts a new charge cycle.A POR or CE toggle also clears the fault.

Condition 2:Charge voltage below recharge threshold (V (RCH))and timeout fault occurs.

Recovery Method:Under this scenario,the bq24070applies the I (FAULT)current.This small current is used to detect a battery removal condition and remains on as long as the battery voltage stays below the recharge threshold.If the battery voltage goes above the recharge threshold,then the bq24070disables the I (FAULT)current and executes the recovery method described for condition 1.Once the battery falls below the recharge threshold,the bq24070clears the fault and starts a new charge cycle.A POR or CE toggle also clears the fault.The output can experience two types of short-circuit protection,one associated with the input and one with the battery.

If the output drops below ~1V,an input short-circuit condition is declared and the input FET,Q1is turned off.To recover from this state,a 500-?pullup resistor from the input is applied (switched)to the output.To recover,the load on the output has to be reduced {Rload >1V ×500?/(Vin–Vout)}such that the pullup resistor is able to lift the output voltage above 1V,for the input FET to be turned back on.

If the output drops 200mV below the battery voltage,the battery FET,Q2is considered in short circuit and the battery FET turns off.To recover from this state,there is a 10-mA current source from the battery to the output.Once the output load is reduced,such that the 10-mA current source can pick up the output within 200mV of the battery,the FET turns back on.

If the short is removed,and the minimum system load is still too large [R<(VBat-200mV)/10mA],the short-circuit protection can be temporarily defeated.The battery short-circuit protection can be disabled (recommended only for a short time)if the voltage on the DPPM pin is less than 1V.Pulsing this pin below 1V,for a few microseconds,should be enough to recover.

This short-circuit disable feature was implemented mainly for power up when inserting a battery.Because the BAT input voltage rises much faster than the OUT voltage (Vout

The V REF is used for internal reference and compensation (3.3V typ).Additionally,it can be used to disable the safety timer and termination by connecting the TMR to the V REF pin.For internal compensation,the V REF pin requires a minimum 0.1-μF ceramic capacitor.The V REF capacitor should not exceed 1μF.

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BQ24072 TI 锂电池 电源管理芯片

bq24072,bq24073 bq24074,bq24075,bq24079 https://www.doczj.com/doc/3011762318.html, SLUS810E–SEPTEMBER2008–REVISED JULY2010 1.5A USB-FRIENDLY Li-Ion BATTERY CHARGER AND POWER-PATH MANAGEMENT IC Check for Samples:bq24072,bq24073,bq24074,bq24075,bq24079 FEATURES DESCRIPTION ?Fully Compliant USB Charger –Selectable100mA and500mA Maximum The bq2407x series of devices are integrated Li-ion linear chargers and system power path management Input Current devices targeted at space-limited portable –100mA Maximum Current Limit Ensures applications.The devices operate from either a USB Compliance to USB-IF Standard port or AC adapter and support charge currents up to –Input based Dynamic Power Management 1.5A.The input voltage range with input overvoltage (V IN-DPM)for Protection Against Poor USB protection supports unregulated adapters.The USB Sources input current limit accuracy and start up sequence allow the bq2407x to meet USB-IF inrush current ?28V Input Rating with Overvoltage Protection specification.Additionally,the input dynamic power ?Integrated Dynamic Power Path Management management(V IN -DPM)prevents the charger from (DPPM)Function Simultaneously and crashing incorrectly configured USB sources. Independently Powers the System and The bq2407x features dynamic power path Charges the Battery management(DPPM)that powers the system while ?Supports up to1.5A Charge Current with simultaneously and independently charging the Current Monitoring Output(ISET)battery.The DPPM circuit reduces the charge current when the input current limit causes the system output ?Programmable Input Current Limit up to1.5A to fall to the DPPM threshold;thus,supplying the for Wall Adapters system load at all times while monitoring the charge ?System Output Tracks Battery Voltage current separately.This feature reduces the number (bq24072) of charge and discharge cycles on the battery,allows ?Programmable Termination Current(bq24074)for proper charge termination and enables the system to run with a defective or absent battery pack.?Battery Disconnect Function with SYSOFF Input(bq24075,bq24079) Typical Application Circuit ?Programmable Pre-Charge and Fast-Charge Safety Timers ?Reverse Current,Short-Circuit and Thermal Protection ?NTC Thermistor Input ?Proprietary Start Up Sequence Limits Inrush Current ?Status Indication–Charging/Done,Power Good ?Small3mm×3mm16Lead QFN Package APPLICATIONS ?Smart Phones ?Portable Media Players ?Portable Navigation Devices ?Low-Power Handheld Devices Please be aware that an important notice concerning availability,standard warranty,and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. Copyright?2008–2010,Texas Instruments Incorporated Products conform to specifications per the terms of the Texas

智能手机电源管理趋势

目前，智能手机的功能越来越多了，不仅允许浏览网页、发送电子邮件、拍照片、播放视频流、玩游戏，甚至还集成了具有高容量存储能力的微型硬盘驱动器作为MP3播放器使用。不过，将这些功能塞进一个外形尺寸受限的产品中，同时还需要获得更长的工作时间，智能手机制造商无疑面临越来越大的压力。 从图1可以看出，功能越多，在不同功率级上就需要越多的低压输出轨。手机中的主电源轨过去通常是3.3V，而较新的手机设计则越来越常采用1.5V的主电源轨，原因是大多数数字大规模集成的IC工作在1.5V或更低的电压上。以下两个例子可以说明这一点，它们都需要1.375V电压的基带芯片组和1.2V电压的应用DSP用于视频处理。 图1: 智能手机方框图 由于受到空间、效率和成本的制约，用负载点(POL)DC/DC转换直接把3.6V的锂电池标称输出电压降至上述较低的电压是不现实的。因此，设计师们采用两步转换的方法。他们先用高效率降压型转换器将锂电池电压降至1.5V，然后从这个1.5V主电源轨，他们可以简单地用非常低压差(VLDO)稳压器为低压数字LSI集成电路供电。由于标称工作电流较低且低压轨之间的转换效率可达80%至90%，因此两步转换方法在很大程度上可能实现，例如从1.5V 降至1.375V以便为基带芯片组内核供电时，效率为91.7%。另一个采用VLDO的理由是，很多需要供电的低压集成电路都是噪声敏感的，因此这些稳压器的输出纹波可能需要低于 1mVP-P。你可以将VLDO作为一个降压型开关稳压器的后稳压器，这样就容易地确保低纹波。 有人可能会说，上述做法没有必要，因为一个毫安小时容量较高的电池就可以解决问题。但消费者喜欢电池又小又轻的手机，这就是大多数手机制造商提供电池标称容量为600mAH 的产品，然后再提供一个较大容量的电池作为附件的原因。同时，外形尺寸受限的手机没有任何散热途径，而且其高功能含量也导致功率预算紧缺，因此高效率DC/DC转换成为优先

了解一下锂电池充电IC的选择方案

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