SLUSBK2I October   2013  – March 2022 BQ76920 , BQ76930 , BQ76940

PRODMIX  

  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Device Comparison Table
  6. Pin Configuration and Functions
    1. 6.1 Versions
    2. 6.2 BQ76920 Pin Diagram
    3. 6.3 BQ76930 Pin Diagram
    4. 6.4 BQ76940 Pin Diagram
  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
    6. 7.6 Timing Requirements
    7. 7.7 Typical Characteristics
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Subsystems
        1. 8.3.1.1 Measurement Subsystem Overview
          1. 8.3.1.1.1 Data Transfer to the Host Controller
          2. 8.3.1.1.2 14-Bit ADC
            1. 8.3.1.1.2.1 Optional Real-Time Calibration Using the Host Microcontroller
          3. 8.3.1.1.3 16-Bit CC
          4. 8.3.1.1.4 External Thermistor
          5. 8.3.1.1.5 Die Temperature Monitor
          6. 8.3.1.1.6 16-Bit Pack Voltage
          7. 8.3.1.1.7 System Scheduler
        2. 8.3.1.2 Protection Subsystem
          1. 8.3.1.2.1 Integrated Hardware Protections
          2. 8.3.1.2.2 Reduced Test Time
        3. 8.3.1.3 Control Subsystem
          1. 8.3.1.3.1 FET Driving (CHG AND DSG)
            1. 8.3.1.3.1.1 High-Side FET Driving
          2. 8.3.1.3.2 Load Detection
          3. 8.3.1.3.3 Cell Balancing
          4. 8.3.1.3.4 Alert
          5. 8.3.1.3.5 Output LDO
        4. 8.3.1.4 Communications Subsystem
    4. 8.4 Device Functional Modes
      1. 8.4.1 NORMAL Mode
      2. 8.4.2 SHIP Mode
    5. 8.5 Register Maps
      1. 8.5.1 Register Details
      2. 8.5.2 Read-Only Registers
  9. Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Device Timing
      2. 9.1.2 Random Cell Connection
      3. 9.1.3 Power Pin Diodes
      4. 9.1.4 Alert Pin
      5. 9.1.5 Sense Inputs
      6. 9.1.6 TSn Pins
      7. 9.1.7 Unused Pins
      8. 9.1.8 Configuring Alternative Cell Counts
    2. 9.2 Typical Applications
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Step-by-Step 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. 12Device and Documentation Support
    1. 12.1 Third-Party Products Disclaimer
    2. 12.2 Documentation Support
    3. 12.3 Related Links
    4. 12.4 Receiving Notification of Documentation Updates
    5. 12.5 Trademarks
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

Register Details

Table 8-3 SYS_STAT (0x00)
BIT 7 6 5 4 3 2 1 0
NAME CC_READY RSVD DEVICE_
XREADY
OVRD_
ALERT
UV OV SCD OCD
RESET 0 0 0 0 0 0 0 0
ACCESS RW RW RW RW RW RW RW RW
Note:

Bits in SYS_STAT may be cleared by writing a "1" to the corresponding bit.

Writing a "0" does not change the state of the corresponding bit.

CC_READY (Bit 7): Indicates that a fresh coulomb counter reading is available. Note that if this bit is not cleared between two adjacent CC readings becoming available, the bit remains latched to 1. This bit may only be cleared (and not set) by the host.
0 = Fresh CC reading not yet available or bit is cleared by host microcontroller.
1 = Fresh CC reading is available. Remains latched high until cleared by host.
RSVD (Bit 6): Reserved. Do not use.
DEVICE_XREADY (Bit 5): Internal chip fault indicator. When this bit is set to 1, it should be cleared by the host. May be set due to excessive system transients. This bit may only be cleared (and not set) by the host.
0 = Device is OK.
1 = Internal chip fault detected, recommend that host microcontroller clear this bit after waiting a few seconds. Remains latched high until cleared by the host.
OVRD_ALERT (Bit 4): External pull-up on the ALERT pin indicator. Only active when ALERT pin is not already being driven high by the AFE itself.
0 = No external override detected
1 = External override detected. Remains latched high until cleared by the host.
UV (Bit 3): Undervoltage fault event indicator.
0 = No UV fault is detected.
1 = UV fault is detected. Remains latched high until cleared by the host.
OV (Bit 2): Overvoltage fault event indicator.
0 = No OV fault is detected.
1 = OV fault is detected. Remains latched high until cleared by the host.
SCD (Bit 1): Short circuit in discharge fault event indicator.
0 = No SCD fault is detected.
1 = SCD fault is detected. Remains latched high until cleared by the host.
OCD (Bit 0): Over current in discharge fault event indicator.
0 = No OCD fault is detected.
1 = OCD fault is detected. Remains latched high until cleared by the host.
Table 8-4 CELLBAL1 (0x01) for BQ76920, BQ76930, and BQ76940
BIT 7 6 5 4 3 2 1 0
NAME CB5 CB4 CB3 CB2 CB1
RESET 0 0 0 0 0 0 0 0
ACCESS R R R RW RW RW RW RW
CBx (Bits 4–0):
0 = Cell balancing on Cell “x” is disabled.
1 = Cell balancing on Cell “x” is enabled.
Table 8-5 CELLBAL2 (0x02) for BQ76930 and BQ76940
BIT 7 6 5 4 3 2 1 0
NAME CB10 CB9 CB8 CB7 CB6
RESET 0 0 0 0 0 0 0 0
ACCESS R R R RW RW RW RW RW
CBx (Bits 4–0):
0 = Cell balancing on Cell “x” is disabled.
1 = Cell balancing on Cell “x” is enabled.
Table 8-6 CELLBAL3 (0x03) for BQ76940
BIT 7 6 5 4 3 2 1 0
NAME CB15 CB14 CB13 CB12 CB11
RESET 0 0 0 0 0 0 0 0
ACCESS R R R RW RW RW RW RW
CBx (Bits 4–0):
0 = Cell balancing on Cell “x” is disabled.
1 = Cell balancing on Cell “x” is enabled.
Table 8-7 SYS_CTRL1 (0x04)
BIT 7 6 5 4 3 2 1 0
NAME LOAD_
PRESENT
ADC_EN TEMP_SEL RSVD SHUT_A SHUT_B
RESET 0 0 0 0 0 0 0 0
ACCESS R R R RW RW RW RW RW
LOAD_PRESENT (Bit 7): Valid only when [CHG_ON] = 0. Is high if CHG pin is detected to exceed VLOAD_DETECT while CHG_ON = 0, which suggests that external load is present. Note this bit is read-only and automatically clears when load is removed.
0 = CHG pin < VLOAD_DETECT or [CHG_ON] = 1.
1 = CHG pin >VLOAD_DETECT, while [CHG_ON] = 0.
ADC_EN (Bit 4): ADC enable command
0 = Disable voltage and temperature ADC readings (also disables OV protection)
1 = Enable voltage and temperature ADC readings (also enables OV protection)
TEMP_SEL (Bit 3): TSx_HI and TSx_LO temperature source
0 = Store internal die temperature voltage reading in TSx_HI and TSx_LO
1 = Store thermistor reading in TSx_HI and TSx_LO (all thermistor ports)
RSVD (Bit 2): Reserved, do not set to 1.
SHUT_A, SHUT_B (Bits 1–0): Shutdown command from host microcontroller. Must be written in a specific sequence, shown below:
Starting from: [SHUT_A] = 0, [SHUT_B] = 0
Write #1: [SHUT_A] = 0, [SHUT_B] = 1
Write #2: [SHUT_A] = 1, [SHUT_B] = 0
Other writes cause the command to be ignored.
Table 8-8 SYS_CTRL2 (0x05)
BIT 7 6 5 4 3 2 1 0
NAME DELAY_DIS CC_EN CC_
ONESHOT
RSVD RSVD RSVD DSG_ON CHG_ON
RESET 0 0 0 0 0 0 0 0
ACCESS RW RW RW RW RW RW RW RW
DELAY_DIS (Bit 7): Disable OV, UV, OCD, and SCD delays for faster customer production testing.
0 = Normal delay settings
1 = OV, UV, OCD, and SCD delay circuit is bypassed, creating zero delay (approximately 250 ms).
CC_EN (Bit 6): Coulomb counter continuous operation enable command. If set high, [CC_ONESHOT] bit is ignored.
0 = Disable CC continuous readings
1 = Enable CC continuous readings and ignore [CC_ONESHOT] state
CC_ONESHOT (Bit 5): Coulomb counter single 250-ms reading trigger command. If set to 1, the coulomb counter will be activated for a single 250-ms reading, and then turned back off. [CC_ONESHOT] will also be cleared at the conclusion of this reading, while [CC_READY] bit will be set to 1.
0 = No action
1 = Enable single CC reading (only valid if [CC_EN] = 0), and [CC_READY] = 0)
RSVD (Bits 4–2): Reserved. Do not use.
DSG_ON (Bit 1): Discharge FET driver (low side NCH) or discharge signal control
0 = DSG is off.
1 = DSG is on.
CHG_ON (Bit 0): Discharge FET driver (low side NCH) or discharge signal control
0 = CHG is off.
1 = CHG is on.
Table 8-9 PROTECT1 (0x06)
BIT 7 6 5 4 3 2 1 0
NAME RSNS RSVD SCD_D1 SCD_D0 SCD_T2 SCD_T1 SCD_T0
RESET 0 0 0 0 0 0 0 0
ACCESS RW R RW RW RW RW RW RW
RSNS (Bit 7): Allows for doubling the OCD and SCD thresholds simultaneously
0 = OCD and SCD thresholds at lower input range
1 = OCD and SCD thresholds at upper input range
RSVD (Bit 5): Reserved, do not set to 1.
SCD_D1:0 (Bits 4–3): Short circuit in discharge delay setting. A 400-µs setting is recommended only in systems using maximum cell measurement input resistance, Rc, of 1 kΩ (which corresponds to minimum internal cell balancing current or external cell balancing configuration).
Code (in µs)
0x0 70
0x1 100
0x2 200
0x3 400
SCD_T2:0 (Bits 2–0): Short circuit in discharge threshold setting
Code RSNS = 1 (in mV) RSNS = 0 (in mV)
0x0 44 22
0x1 67 33
0x2 89 44
0x3 111 56
0x4 133 67
0x5 155 78
0x6 178 89
0x7 200 100
Table 8-10 PROTECT2 (0x07)
BIT 7 6 5 4 3 2 1 0
NAME OCD_D2 OCD_D1 OCD_D0 OCD_T3 OCD_T2 OCD_T1 OCD_T0
RESET 0 0 0 0 0 0 0 0
ACCESS R RW RW RW RW RW RW RW
OCD_D2:0 (Bits 6–4): Overcurrent in discharge delay setting
Code (in ms)
0x0 8
0x1 20
0x2 40
0x3 80
0x4 160
0x5 320
0x6 640
0x7 1280
OCD_T3:0 (Bits 3–0): Overcurrent in discharge threshold setting
Code RSNS = 1 (in mV) (RSNS = 0 (in mV)
0x0 17 8
0x1 22 11
0x2 28 14
0x3 33 17
0x4 39 19
0x5 44 22
0x6 50 25
0x7 56 28
0x8 61 31
0x9 67 33
0xA 72 36
0xB 78 39
0xC 83 42
0xD 89 44
0xE 94 47
0xF 100 50
Table 8-11 PROTECT3 (0x08)
BIT 7 6 5 4 3 2 1 0
NAME UV_D1 UV_D0 OV_D1 OV_D0 RSVD RSVD RSVD RSVD
RESET 0 0 0 0 0 0 0 0
ACCESS RW RW RW RW RW RW RW RW
UV_D1:0 (Bits 7–6): Undervoltage delay setting
Code (in s)
0x0 1
0x1 4
0x2 8
0x3 16
OV_D1:0 (Bits 5–4): Overvoltage delay setting
Code (in s)
0x0 1
0x1 2
0x2 4
0x3 8
RSVD (Bits 3–0): These bits are for TI internal debug use only and must be configured to the default settings indicated.
Table 8-12 OV_TRIP (0x09)
BIT 7 6 5 4 3 2 1 0
NAME OV_T7 OV_T6 OV_T5 OV_T4 OV_T3 OV_T2 OV_T1 OV_T0
RESET 1 0 1 0 1 1 0 0
ACCESS RW RW RW RW RW RW RW RW
OV_T7:0 (Bits 7–0): Middle 8 bits of the direct ADC mapping of the desired OV protection threshold, with upper 2 MSB set to 10 and lower 4 LSB set to 1000. The equivalent OV threshold is mapped to:
10-OV_T<7:0>1000.
By default, OV_TRIP is configured to a 0xAC setting.
Note that OV_TRIP is based on the ADC voltage, which requires back-calculation using the GAIN and OFFSET values stored in ADCGAIN<4:0>and ADCOFFSET<7:0>.
Table 8-13 UV_TRIP (0x0A)
BIT 7 6 5 4 3 2 1 0
NAME UV_T7 UV_T6 UV_T5 UV_T4 UV_T3 UV_T2 UV_T1 UV_T0
RESET 1 0 0 1 0 1 1 1
ACCESS RW RW RW RW RW RW RW RW
UV_T7:0 (Bits 7–0): Middle 8 bits of the direct ADC mapping of the desired UV protection threshold, with upper 2 MSB set to 01 and lower 4 LSB set to 0000. In other words, the equivalent OV threshold is mapped to: 01-UV_T<7:0>–0000.
By default, UV_TRIP is configured to a 0x97 setting.
Note that UV_TRIP is based on the ADC voltage, which requires back-calculation using the GAIN and OFFSET values stored in ADCGAIN<4:0>and ADCOFFSET<7:0>.
Table 8-14 CC_CFG REGISTER (0x0B)
BIT 7 6 5 4 3 2 1 0
NAME CC_CFG5 CC_CFG4 CC_CFG3 CC_CFG2 CC_CFG1 CC_CFG0
RESET 0 0 0 0 0 0 0 0
ACCESS R R RW RW RW RW RW RW
CC_CFG5:0 (Bits 5–0): For optimal performance, these bits should be programmed to 0x19 upon device startup.