ZHCSP56 September 2023 TPS1HTC30-Q1
PRODUCTION DATA
- 1
- 1 特性
- 2 應用
- 3 說明
- 4 Revision History
- 5 Pin Configuration and Functions
- 6 Specifications
- 7 Parameter Measurement Information
- 8 Detailed Description
- 9 Application and Implementation
- 10Device and Documentation Support
- 11Mechanical, Packaging, and Orderable Information
8.3.5.2 Open-Load Detection
When the main channel is enabled faults are diagnosed by reading the voltage on the SNS pin and judged by the user.
In the off state, if a load is connected, the output voltage is pulled to 0V. In the case of an open load, the output voltage is close to the supply voltage, VS – VOUT < Vol,off. The FLT pin goes low to indicate the fault to the MCU, and the SNS pin is pulled up to VSNSFH. There is always a leakage current Iol,off present on the output, due to the internal logic control path or external humidity, corrosion, and so forth. Thus, TI implemented an internal pullup resistor to offset the leakage current. This pullup current must be less than the output load current to avoid false detection in the normal operation mode. To reduce the standby current, TI implimented a switch in series with the pullup resistor controlled by the DIAG_EN pin. The pull up resistor value is Rpu = 150 kΩ.
Figure 8-10 Open-Load Detection Circuit