ZHCS327D July   2011  – October 2016 BQ76925

PRODUCTION DATA.  

  1. 1 特性
  2. 2 应用
  3. 3 说明
  4. 4 修订历史记录
  5. 5 说明 （续）
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1  Absolute Maximum Ratings
    2. 7.2  ESD Ratings
    3. 7.3  Recommended Operating Conditions
    4. 7.4  Thermal Information
    5. 7.5  Electrical Characteristics: Supply Current
    6. 7.6  Internal Power Control (Startup and Shutdown)
    7. 7.7  3.3-V Voltage Regulator
    8. 7.8  Voltage Reference
    9. 7.9  Cell Voltage Amplifier
    10. 7.10 Current Sense Amplifier
    11. 7.11 Overcurrent Comparator
    12. 7.12 Internal Temperature Measurement
    13. 7.13 Cell Balancing and Open Cell Detection
    14. 7.14 I2C Compatible Interface
    15. 7.15 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Internal LDO Voltage Regulator
      2. 8.3.2 ADC Interface
        1. 8.3.2.1 Reference Voltage
          1. 8.3.2.1.1 Host ADC Calibration
        2. 8.3.2.2 Cell Voltage Monitoring
          1. 8.3.2.2.1 Cell Amplifier Headroom Under Extreme Cell Imbalance
          2. 8.3.2.2.2 Cell Amplifier Headroom Under BAT Voltage Drop
        3. 8.3.2.3 Current Monitoring
        4. 8.3.2.4 Overcurrent Monitoring
        5. 8.3.2.5 Temperature Monitoring
          1. 8.3.2.5.1 Internal Temperature Monitoring
      3. 8.3.3 Cell Balancing and Open Cell Detection
    4. 8.4 Device Functional Modes
      1. 8.4.1 Power Modes
        1. 8.4.1.1 POWER ON RESET (POR)
        2. 8.4.1.2 STANDBY
        3. 8.4.1.3 SLEEP
    5. 8.5 Programming
      1. 8.5.1 Host Interface
        1. 8.5.1.1 I2C Addressing
        2. 8.5.1.2 Bus Write Command to bq76925
        3. 8.5.1.3 Bus Read Command from bq76925 Device
    6. 8.6 Register Maps
      1. 8.6.1 Register Descriptions
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Recommended System Implementation
        1. 9.1.1.1 Voltage, Current, and Temperature Outputs
        2. 9.1.1.2 Power Management
        3. 9.1.1.3 Low Dropout (LDO) Regulator
        4. 9.1.1.4 Input Filters
        5. 9.1.1.5 Output Filters
      2. 9.1.2 Cell Balancing
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12器件和文档支持
    1. 12.1 文档支持
      1. 12.1.1 相关文档
    2. 12.2 接收文档更新通知
    3. 12.3 社区资源
    4. 12.4 商标
    5. 12.5 静电放电警告
    6. 12.6 Glossary
  13. 13机械、封装和可订购信息

7 Specifications

7.1 Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted) (1)
MIN MAX UNIT
VBAT Supply voltage BAT –0.3 36 V
VI Input voltage Cell input differential, VCn to VCn+1, n = 0 to 5 –0.3 9 V
Cell input, VCn, n = 1 to 6 –0.3 (6 × n)
BAT to VC6 differential –10 10
VC0 (2) –3 3
SENSEP, SENSEN –3 3
SCL, SDA –0.3 6
VO Output voltage VCOUT, VIOUT, VREF –0.3 3.6 V
VTB, V3P3 –0.3 7
ALERT –0.3 30
VCTL –0.3 36
ICB Cell balancing current 70 mA
IIN Cell input current –25 70 mA
Tstg Storage temperature –65 150 °C
(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
(2) Negative voltage swings on VC0 in the absolute maximum range can cause unwanted circuit behavior and should be avoided.

7.2 ESD Ratings

VALUE UNIT
V(ESD) Electrostatic discharge Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) ±2000 V
Charged-device model (CDM), per JEDEC specification JESD22-C101(2) ±500
(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
(2) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.

7.3 Recommended Operating Conditions(1)

MIN NOM MAX UNIT
Supply voltage BAT 4.2 26.4 V
VI Input voltage Cell input differential, VCn to VCn+1, n = 0 to 5 1.4 4.4 V
Cell input, VCn, n = 1 to 6 4.4 × n V
BAT to VC6 differential –8 8 V
VC0, SENSEN 0 V
SENSEP –125 375 mV
SCL, SDA 0 5.5 V
V3P3 Backfeeding(2) 5.5 V
ALERT Wakeup function 0 26.4 V
VO Output voltage VCOUT, VIOUT 0 V3P3 + 0.2 V
VREF REFSEL = 0 1.5 V
REFSEL = 1 3 V
VTB 5.5 V
V3P3 Regulating 3.3 V
VCTL 0.8 26.4 V
ALERT Alert function 0 5.5 V
ICB Cell balancing current 0 50 mA
TA Operating free-air temperature –25 85 °C
TFUNC Functional free-air temperature –40 100 °C
(1) All voltages are relative to VSS, except “Cell input differential.”
(2) Internal 3.3-V regulator may be overridden (that is, backfed) by applying an external voltage larger than the regulator voltage.

7.4 Thermal Information

THERMAL METRIC(1) bq76925 UNIT
PW (TSSOP) RGE (VQFN)
20 PINS 24 PINS
RθJA Junction-to-ambient thermal resistance 97.5 36 °C/W
RθJC (top) Junction-to-case (top) thermal resistance 31.7 38.6 °C/W
RθJB Junction-to-board thermal resistance 48.4 14 °C/W
ψJT Junction-to-top characterization parameter 1.5 0.6 °C/W
ψJB Junction-to-board characterization parameter 47.9 14 °C/W
RθJC (bot) Junction-to-case (bottom) thermal resistance n/a 4.6 °C/W
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report.

7.5 Electrical Characteristics: Supply Current

BAT = 4.2 to 26.4 V, VCn = 1.4 to 4.4, TA = –25°C to +85°C
Typical values stated where TA = 25°C and BAT= 21.6 V (unless otherwise noted)
PARAMETER TEST CONDITION MIN TYP MAX UNIT
IDD1 Normal mode supply current All device functions enabled
All pins unloaded
SDA and SCL high		 40 48 µA
IDD2 Standby mode 1 supply current V3P3 and overcurrent monitor enabled
All pins unloaded
All other device functions disabled
SDA and SCL high		 14 17 µA
IDD3 Standby mode 2 supply current V3P3 enabled
All pins unloaded
All device functions disabled
SDA and SCL high		 12 14 V
IDD4 Sleep mode supply current V3P3 disabled
All pins unloaded
All device functions disabled
SDA and SCL low		 1 1.5 µA
IVCn Input current for selected cell All cell voltages equal
Cell balancing disabled
Open cell detection disabled
during cell voltage monitoring		 n = 6 2.4 2.7 µA
n = 1 – 5 < 0.5
n = 1 – 5 at 25°C < 0.3
∆IVCn Cell to cell input current difference All cell voltages equal
Cell balancing disabled
Open cell detection disabled		 < 0.2 µA

7.6 Internal Power Control (Startup and Shutdown)

PARAMETER TEST CONDITION MIN TYP MAX UNIT
VPOR Power on reset voltage Measured at BAT pin Initial BAT < 1.4 VBAT rising(1) 4.3 4.5 4.7 V
Initial BAT > 1.4 VBAT rising(1) 6.5 7 7.5 V
VSHUT Shutdown voltage(2) Measured at BAT pin, BAT falling 3.6 V
tPOR Time delay after POR before I2C comms allowed CV3P3 = 4.7 µF 1 ms
VWAKE Wakeup voltage Measured at ALERT pin 0.8 2 V
tWAKE_PLS Wakeup signal pulse width 1 5 μs
tWAKE_DLY Time delay after wakeup before I2C comms allowed CV3P3 = 4.7 µF 1 ms
(1) Initial power up will start with BAT < 1.4 V, however if BAT falls below VSHUT after rising above VPOR, the power on threshold depends on the minimum level reached by BAT after falling below VSHUT.
(2) Following POR, the device will operate down to this voltage.

7.7 3.3-V Voltage Regulator

PARAMETER TEST CONDITION MIN TYP MAX UNIT
VCTL Regulator control voltage (1)(2) Measured at VCTL, V3P3 regulating 3.3 26.4 V
VV3P3 Regulator output Measured at V3P3, IREG = 0 to 4 mA,
BAT = 4.2 to 26.4 V		 3.2 3.3 3.4 V
IREG V3P3 output current 4 mA
ISC V3P3 short circuit current limit V3P3 = 0.0 V 10 17 mA
VTB Thermistor bias voltage Measured at VTB, ITB = 0 VV3P3 V
ITB Thermistor bias current 1 mA
RTB Thermistor bias internal resistance RDS(ON) for internal FET switch, ITB = 1 mA 90 130 Ω
(1) When a bypass FET is used to supply the regulated 3.3 V load current, VCTL automatically adjusts to keep V3P3 = 3.3 V. Note that VCTL,MIN and the FET VGS will determine the minimum BAT voltage at which the bypass FET will operate.
(2) If VCTL is tied to BAT, the load current is supplied through V3P3.

7.8 Voltage Reference

PARAMETER TEST CONDITION MIN TYP MAX UNIT
VREF Voltage reference output Before gain correction,
TA = 25°C		 REF_SEL = 0 1.44 1.56 V
REF_SEL = 1 2.88 3.12
After gain correction, (1)
TA = 25°C		 REF_SEL = 0 –0.1% 1.5 +0.1%
REF_SEL = 1 –0.1% 3 +0.1%
VREF_CAL Reference calibration voltage Measured at VCOUT VCOUT_SEL = 2 –0.9% 0.5 × VREF +0.9% V
VCOUT_SEL = 3 –0.5% 0.85 × VREF +0.5%
(0.85 × VREF) – (0.5 × VREF) –0.3% 0.35 × VREF +0.3% V
∆VREF Voltage reference tolerance TA = 0 – 50°C –40 40 ppm/°C
IREF VREF output current 10 µA
(1) Gain correction factor determined at final test and stored in non-volatile storage. Gain correction is applied by Host controller.

7.9 Cell Voltage Amplifier

PARAMETER TEST CONDITION MIN TYP MAX UNIT
GVCOUT Cell voltage amplifier gain Measured from VCn
to VCOUT		 REF_SEL = 0 –1.6% 0.3 1.5%
REF_SEL = 1 –1.6% 0.6 1.5%
OVCOUT Cell voltage amplifier offset Measured from VCn to VCOUT –16 15 mV
VCOUT Cell voltage amp output range (1) Measured at VCOUT,
VCn = 5 V		 REF_SEL = 0 1.47 1.5 1.53 V
REF_SEL = 1 2.94 3 3.06 V
Measured at VCOUT,
VCn = 0 V		 0 V
∆VCOUT Cell voltage amplifier accuracy VCn = 1.4 V to 4.4 V,
After correction, (2)
Measured at VCOUT (3)
REF_SEL = 1(4)		 TA = 25°C –3 3 mV
TA = 0°C to 50°C –5 5
TA = –25°C to +85°C –8 8
IVCOUT VCOUT output current(5) 10 µA
tVCOUT Delay from VCn select to VCOUT Output step of 200 mV, COUT = 0.1 µF 100 µs
(1) For VCn values greater than 5 V, VCOUT clamps at approximately V3P3.
(2) Correction factor determined at final test and stored in non-volatile storage. Correction is applied by Host controller.
(3) Output referred. Input referred accuracy is calculated as ∆VCOUT / GVCOUT (for example, 3 / 0.6 = 5).
(4) Correction factors are calibrated for gain of 0.6. Tolerance at gain of 0.3 is approximately doubled. Contact TI for information on devices calibrated to a gain of 0.3.
(5) Max DC load for specified accuracy.

7.10 Current Sense Amplifier

PARAMETER TEST CONDITION MIN TYP MAX UNIT
GVIOUT Current sense amplifier gain Measured from SENSEN,
SENSEP to VIOUT		 I_GAIN = 0 4
I_GAIN = 1 8
VIIN Current sense amp input range Measured from SENSEN,
SENSEP to VSS		 –125 375 mV
VIOUT Current sense amp output range Measured at VIOUT REF_SEL = 0 0.25 1.25 V
REF_SEL = 1 0.5 2.5 V
Zero current output Measured at VIOUT
SENSEP = SENSEN		 REF_SEL = 0 1 V
REF_SEL = 1 2 V
∆VIOUT Current amplifier accuracy –1% 1%
IVIOUT VIOUT output current (1) 10 µA
(1) Max DC load for specified accuracy

7.11 Overcurrent Comparator

PARAMETER TEST CONDITION MIN TYP MAX UNIT
VBAT_COMP Minimum VBAT for comparator operation(1) 5 V
GVCOMP Comparator amplifier gain Measured from SENSEP to comparator input 1
VITRIP Current comparator trip threshold(2) 25 400 mV
∆VITRIP Current comparator accuracy VITRIP = 25 mV –6 6 mV
VITRIP > 25 mV –10% 10% V
VOL_ALERT ALERT Output Low Logic IALERT = 1 mA 0.4 V
VOH_ALERT ALERT Output High Logic (3) NA NA NA
IALERT ALERT Pulldown current ALERT = 0.4 V, Output driving low 1 mA
IALERT_LKG ALERT Leakage current ALERT = 5 V, Output Hi-Z < 1 μA
tOC Comparator response time 100 µs
(1) The Overcurrent Comparator is not guaranteed to work when VBAT is below this voltage.
(2) Trip threshold selectable from 25, 50, 75, 100, 125, 150, 175, 200, 225, 250, 275, 300, 325, 350, 375 or 400 mV.
(3) This parameter NA because output is open drain.

7.12 Internal Temperature Measurement

PARAMETER TEST CONDITION MIN TYP MAX UNIT
VTEMP_INT Internal temperature voltage Measured at VCOUT, TINT = 25°C 1.15 1.2 1.25 V
∆VTEMP_INT Internal temperature voltage sensitivity –4.4 mV/°C

7.13 Cell Balancing and Open Cell Detection

PARAMETER TEST CONDITION MIN TYP MAX UNIT
RBAL Cell balancing internal resistance(1) RDS(ON) for VC1 internal FET switch, VCn = 3.6 V 1 3 5 Ω
RDS(ON) for internal VC2 to VC6 FET switch, VCn = 3.6 V 3 5.5 8
(1) Balancing current is not internally limited. The cell balancing operation is completely controlled by the Host processor, no automatic function or time-out is included in the part. Take care to ensure that balancing current through the part is below the maximum power dissipation limit. The Host algorithm is responsible for limiting thermal dissipation to package ratings.

7.14 I2C Compatible Interface

PARAMETERS MIN TYP MAX UNIT
DC PARAMETERS
VIL Input Low Logic Threshold 0.6 V
VIH Input High Logic Threshold 2.8 V
VOL Output Low Logic Drive IOL = 1 mA 0.20 V
IOL = 2.5 mA 0.40
VOH Output High Logic Drive (Not applicable due to open-drain outputs) N/A V
ILKG I2C Pin Leakage Pin = 5 V, Output in Hi-Z < 1 µA
AC PARAMETERS
tr SCL, SDA　Rise Time 1000 ns
tf SCL, SDA　Fall Time 300 ns
tw(H) SCL Pulse Width High 4 µs
tw(L) SCL Pulse Width Low 4.7 µs
tsu(STA) Setup time for START condition 4.7 µs
th(STA) START condition hold time after which first clock pulse is generated 4 µs
tsu(DAT) Data setup time 250 ns
th(DAT) Data hold time 0(1) µs
tsu(STOP) Setup time for STOP condition 4 µs
tsu(BUF) Time the bus must be free before new transmission can start 4.7 µs
t V Clock Low to Data Out Valid 900 ns
th(CH) Data Out Hold Time After Clock Low 0 ns
fSCL Clock Frequency 0 100 kHz
tWAKE I2C ready after transition to Wake Mode 2.5 ms
(1) Devices must provide internal hold time of at least 300 ns for the SDA signal-to-bridge of the undefined region of the falling edge of SCL.
bq76925 I2C_time_lusam9.gif Figure 1. I2C Timing

7.15 Typical Characteristics

bq76925 D001_SLUSAM9.gif
Figure 2. Normal Mode Supply Current
bq76925 D003_SLUSAM9.gif
Figure 4. Regulator Output With 4 mA Load
bq76925 D005_SLUSAM9.gif
Figure 6. 1.5-V VREF Output (Before Correction)
bq76925 D002_SLUSAM9.gif
Figure 3. Sleep Mode Supply Current
bq76925 D004_SLUSAM9.gif
Figure 5. Regulator Output With No Load
bq76925 D006_SLUSAM9.gif
Figure 7. 3-V VREF Output (Before Correction)