ZHCSI27C April 2018 – October 2021 LM5036
PRODUCTION DATA
As described in Section 7.3.17, the ON_OFF pin can be configured as a latch pin or an OVP pin. Figure 7-20 shows the latch configuration. The ON_OFF pin is latched when the pin voltage reaches IOVL × RL when any of the internal faults is detected. The latch diode is reverse-biased during latch operation. Select the latch resistor RL value such that IOVL × RL > VON_OFF. This design example uses an RL value of 49.9 k?. If the latch threshold is 80 V, use an ROV1 value of 40 k?, and use an ROV2 value of 710 ?.
If the ON_OFF pin is configured as an OVP pin, two resistors can be used to program the maximum operating input voltage for the half-bridge converter, as illustrated in Figure 7-21. When the ON_OFF pin voltage rises above the VON_OFF threshold, an internal current source IOVL is enabled to raise the ON_OFF pin voltage, thus providing the threshold hysteresis. Use Equation 29 and Equation 30 to determine resistance values for ROV1 and ROV2. If the LM5036 controller is to be disabled when VIN rises above 80 V and enabled when it falls below 78 V. Use an ROV1 value of 40-k?, and an ROV2 value of 635-?. The ON_OFF pin can also be used for external thermal protection with a thermistor.