ZHCSQI2A November 2022 – January 2024 TPS92620-Q1
PRODUCTION DATA
- 1
- 1 特性
- 2 應用
- 3 說明
- 4 Pin Configuration and Functions
- 5 Specifications
-
6 Detailed Description
- 6.1 Overview
- 6.2 Functional Block Diagram
- 6.3
Feature Description
- 6.3.1 Power Supply (SUPPLY)
- 6.3.2 Enable and Shutdow(EN)
- 6.3.3 Constant-Current Output and Setting (INx)
- 6.3.4 Thermal Sharing Resistor (OUTx and RESx)
- 6.3.5 PWM Control (PWMx)
- 6.3.6 Supply Control
- 6.3.7 Diagnostics
- 6.3.8 FAULT Bus Output With One-Fails-All-Fail
- 6.3.9 FAULT Table
- 6.3.10 LED Fault Summary
- 6.3.11 IO Pins Inner Connection
- 6.4 Device Functional Modes
- 7 Application and Implementation
- 8 Device and Documentation Support
- 9 Revision History
- 10Mechanical, Packaging, and Orderable Information
封裝選項
機械數據 (封裝 | 引腳)
散熱焊盤機械數據 (封裝 | 引腳)
- DRR|12
訂購信息
6.3.7.2 LED Open-Circuit Detection
The TPS92620-Q1 device has LED open-circuit detection. The LED open-circuit detection monitors the output voltage when the current output is enabled. The LED open-circuit detection is only enabled when DIAGEN is HIGH. A short-to-battery fault is also detected and recognized as an LED open-circuit fault.
The TPS92620-Q1 monitors dropout-voltage differences between the IN and OUT pins for each LED channel when PWM is HIGH. The voltage difference V(INx) – V(OUTx) is compared with the internal reference voltage V(OPEN_th_rising) to detect an LED open-circuit incident. If V(OUTx) rises and causes V(INx) – V(OUTx) less than the V(OPEN_th_rising) voltage longer than the deglitch time of t(OPEN_deg), the device asserts an open-circuit fault. After a LED open-circuit failure is detected, the internal constant-current sink pulls down the FAULT pin voltage. During the deglitch time period, if V(OUTx) falls and makes V(INx) – V(OUTx) larger than V(OPEN_th_falling), the deglitch timer is reset.
The TPS92620-Q1 shuts down the output current regulation for the error channel after LED open-circuit fault is detected. The device sources a small current I(Retry) from SUPPLY to OUT and RES when DIAGEN input is logic High. After the fault condition is removed, the device resumes normal operation and releases the FAULT pin. Figure 6-4 illustrates the timing for LED open-circuit detection, protection, retry and recovery.
Figure 6-4 LED Open-Circuit Detection and
Recovery Timing DiagramThe detailed information and value of each time period in Figure 6-4 is described in TIMING section of the Electrical Characteristics.