ZHCSQT8 October 2023 LM74930-Q1
PRODUCTION DATA
RSET is the resistor connected between C and CS+ pin. This resistor scales the overcurrent protection threshold voltage and coordinates with RILIM and RIMON to determine the overcurrent protection threshold and current monitoring output. The recommended range of RSET is 50 Ω to 100 Ω. RSET is selected as 50 Ω, 1% for this design example.
LM74930-Q1 default short circuit threshold of 20 mV can be shifted to higher value as given by Equation 14.
For this application, ISCP pin is shorted directly to C pion (Drain of Q2). User has a flexibility to populate suitable value of RISCP resistor to adjust short circuit protection current limit and also gives flexibility in terms of selecting different current sense resistor value.
An additional de-glitch filter (optional) consisting of RISCP and CSCP can be added from ISCP pin to CS– pin as shown in Figure 8-1 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 2 A.