ZHCSO86B december 2022 – july 2023 LM74900-Q1 , LM74910-Q1
PRODUCTION DATA
LM749x0-Q1 offers fast response to any short circuit events with the short circuit protection feature. Once the voltage across CS+ and CS– exceeds the ISCP set point of 20-mV typical (default threshold), HGATE is pulled to OUT within 5 µs protecting the HFET. FLT asserts low at the same time. Subsequent to this event, the charge/discharge cycles of CTMR starts similar to the behavior post FET OFF event in circuit breaker operation.
Short circuit protection threshold can be increased using an external series resistor (RISCP) from ISCP pin to common drain point. The shift in the short circuit protection threshold can be calculated using Equation 7.
An additional deglitch filter consisting of RSCP and CSCP can be added from ISCP pin to CS– pin as shown in Figure 9-7 to avoid any false short circuit trigger in case of fast automotive transients such as Input Micro cuts (LV124, E-10), AC superimpose (LV124, E-06), ISO7637-2 Pulse 2A.
Latch off can also achieved in the similar way as explained in the circuit breaker section.