ZHCSHU6L march 2018 – august 2023 BQ77915
PRODUCTION DATA
- 1
- 1 特性
- 2 應(yīng)用
- 3 說明
- 4 Revision History
- 5 說明（續(xù)）
- 6 Device Comparison Table
- 7 Pin Configuration and Functions
- 8 Specifications
-
9 Detailed Description
- 9.1 Overview
- 9.2 Functional Block Diagram
- 9.3
Feature Description
- 9.3.1 Protection Summary
- 9.3.2
Fault Operation
- 9.3.2.1 Operation in OV
- 9.3.2.2 Operation in UV
- 9.3.2.3 Operation in OW
- 9.3.2.4 Operation in OCD1
- 9.3.2.5 Operation in OCD2
- 9.3.2.6 Programming the OCD1/2 Delay Using the OCDP Pin
- 9.3.2.7 Operation in SCD
- 9.3.2.8 Operation in OCC
- 9.3.2.9 Overcurrent Recovery Timer
- 9.3.2.10 Load Detection and Load Removal Detection
- 9.3.2.11 Operation in OTC
- 9.3.2.12 Operation in OTD
- 9.3.2.13 Operation in UTC
- 9.3.2.14 Operation in UTD
- 9.3.3 Protection Response and Recovery Summary
- 9.3.4 Cell Balancing
- 9.3.5 HIBERNATE Mode Operation
- 9.3.6 Configuration CRC Check and Comparator Built-In-Self-Test
- 9.3.7 Fault Detection Method
- 9.3.8 State Comparator
- 9.3.9 DSG FET Driver Operation
- 9.3.10 CHG FET Driver Operation
- 9.3.11 External Override of CHG and DSG Drivers
- 9.3.12 Configuring 3-Series, 4-Series, or 5-Series Modes
- 9.3.13 Stacking Implementations
- 9.3.14 Zero-Volt Battery Charging Inhibition
- 9.4 Device Functional Modes
-
10Application and Implementation
- 10.1
Application Information
- 10.1.1 Recommended System Implementation
- 10.2 Typical Application
- 10.1
Application Information
- 11Power Supply Recommendations
- 12Layout
- 13Device and Documentation Support
- 14Mechanical, Packaging, and Orderable Information
封裝選項(xiàng)
機(jī)械數(shù)據(jù) (封裝 | 引腳)
- PW|24
散熱焊盤機(jī)械數(shù)據(jù) (封裝 | 引腳)
訂購信息
9.3.8 State Comparator
A small, low-offset analog state comparator monitors the sense resistor voltage (SRP–SRN) to determine when the pack is in a DISCHARGE state less than a minimum threshold, VSTATE_D, or a CHARGE state greater than a maximum threshold, VSTATE_C. The state comparator turns on the CHG FET to prevent damage or overheating during discharge in fault states that call for having only the CHG FET off. This is vice versa for the DSG FET during charging in fault that call for having only the DSG FET off. Also, the state comparator is turned on in NORMAL mode (CHG and DSG FETs on) during cell balancing so that cell balancing is performed only when the pack is charging.
Table 9-6 summarizes when the state comparator is operational. The state comparator is on only during faults detected that call for only one FET to be turned off, and in NORMAL mode during cell balancing so that cell balancing is performed only when the pack is charging.
| MODE | CHG | DSG | STATE COMP |
|---|---|---|---|
| NORMAL mode, no cell balancing | ON | ON | OFF |
| NORMAL mode, cell balancing | ON | ON | VSTATE_C detection |
| UV, CTRD | ON | OFF | VSTATE_C detection |
| OV, UTC, OTC, CTRC | OFF | ON | VSTATE_D detection |
| OCD1, OCD2, SCD, OCC, UTD, OTD, OW | OFF | OFF | OFF |
Figure 9-7 State Comparator ThresholdsAny time a CHG fault is present and a DSG fault is not present, the device enables the state comparator. If the pack is in a fault state where charging is prohibited but discharging is permitted (OV, OTC, UTC, and CTRC), a discharge is possible. When this happens, the CHG FET driver is turned on to avoid damage, as it otherwise carries the discharge current through its body diode. The state comparator (with the VSTATE_D threshold and VSTATE_D_HYS hysteresis) remains on for the entire duration of a CHG fault with no DSG fault event.
If there is a DSG fault under CTRD conditions, the DSG FET is turned on if charge is detected. The state comparator (with VSTATE_C threshold and VSTATE_C_HYS hysteresis) remains on for the entire duration of a DSG fault with no CHG fault event.