ZHCSVT2A April 2022 – April 2024 BQ76922
PRODUCTION DATA
- 1
- 1 特性
- 2 应用
- 3 说明
- 4 Device Comparison Table
- 5 Pin Configuration and Functions
-
6 Specifications
- 6.1 Absolute Maximum Ratings
- 6.2 ESD Ratings
- 6.3 Recommended Operating Conditions
- 6.4 Thermal Information BQ76922
- 6.5 Supply Current
- 6.6 Digital I/O
- 6.7 LD Pin
- 6.8 Precharge (PCHG) and Predischarge (PDSG) FET Drive
- 6.9 FUSE Pin Functionality
- 6.10 REG18 LDO
- 6.11 REG0 Pre-regulator
- 6.12 REG1 LDO
- 6.13 Voltage References
- 6.14 Coulomb Counter
- 6.15 Coulomb Counter Digital Filter (CC1)
- 6.16 Current Measurement Digital Filter (CC2)
- 6.17 Current Wake Detector
- 6.18 Analog-to-Digital Converter
- 6.19 Cell Balancing
- 6.20 Cell Open Wire Detector
- 6.21 Internal Temperature Sensor
- 6.22 Thermistor Measurement
- 6.23 Internal Oscillators
- 6.24 High-side NFET Drivers
- 6.25 Comparator-Based Protection Subsystem
- 6.26 Timing Requirements – I2C Interface, 100kHz Mode
- 6.27 Timing Requirements – I2C Interface, 400kHz Mode
- 6.28 Timing Requirements – HDQ Interface
- 6.29 Interface Timing Diagrams
- 6.30 Typical Characteristics
-
7 Detailed Description
- 7.1 Overview
- 7.2 Functional Block Diagram
- 7.3 Diagnostics
- 7.4 Device Configuration
- 7.5
Measurement Subsystem
- 7.5.1 Voltage Measurement
- 7.5.2 General Purpose ADCIN Functionality
- 7.5.3 Coulomb Counter and Digital Filters
- 7.5.4 Synchronized Voltage and Current Measurement
- 7.5.5 Internal Temperature Measurement
- 7.5.6 Thermistor Temperature Measurement
- 7.5.7 Factory Trim of Voltage ADC
- 7.5.8 Voltage Calibration (ADC Measurements)
- 7.5.9 Voltage Calibration (COV and CUV Protections)
- 7.5.10 Current Calibration
- 7.5.11 Temperature Calibration
- 7.6 Primary and Secondary Protection Subsystems
- 7.7
Device
Hardware Features
- 7.7.1 Voltage References
- 7.7.2 ADC Multiplexer
- 7.7.3 LDOs
- 7.7.4 Standalone Versus Host Interface
- 7.7.5 Multifunction Pin Controls
- 7.7.6 RST_SHUT Pin Operation
- 7.7.7 CFETOFF, DFETOFF, and BOTHOFF Pin Functionality
- 7.7.8 ALERT Pin Operation
- 7.7.9 Fuse Drive
- 7.7.10 Cell Open Wire
- 7.7.11 Low Frequency Oscillator
- 7.7.12 High Frequency Oscillator
- 7.8 Device Functional Modes
- 7.9 Serial Communications Interface
- 7.10 Cell Balancing
- 8 Application and Implementation
- 9 Power Supply Requirements
- 10Layout
- 11Device and Documentation Support
- 12Revision History
- 13Mechanical, Packaging, Orderable Information
7.7.9 Fuse Drive
The FUSE pin on the BQ76922 device can be used to blow a chemical fuse in the presence of a Permanent Fail (PF), as well as to determine if an external secondary protector in the system has detected a fault and is attempting to blow the fuse itself. The pin can drive the gate of an NFET, which can be combined with the drive from an external secondary protector, as shown in Figure 7-4. When the FUSE pin is not asserted by the BQ76922 device, it remains in a high-impedance state and detects a voltage applied at the pin by a secondary protector. The device can be configured to generate a PF if it detects a high signal at the FUSE pin.
The device can be configured to blow the fuse when a PF occurs. In this case, the device will only attempt to blow the fuse if the stack voltage is above a programmed threshold, based on a system configuration with the fuse placed between the top of stack and the high-side protection FETs. If instead the fuse is placed between the FETs and the PACK+ connector, then the device bases its decision on the PACK pin voltage (based on configuration setting). This voltage threshold check may be disregarded under certain special cases, as described in the BQ76922 Technical Reference Manual.
Figure 7-4 FUSE Pin Operation