JAJSHL5H October 2011 – June 2019 LMR24210
PRODUCTION DATA.
A start-up regulator is integrated within the LMR24210. The input pin VIN can be connected directly to a line voltage up to 42 V. The VCC output regulates at 6 V, and is current limited to 65 mA. Upon power up, the regulator sources current into an external capacitor CVCC, which is connected to the VCC pin. For stability, CVCC must be at least 680 nF. When the voltage on the VCC pin is higher than the undervoltage lockout (UVLO) threshold of 3.75 V, the main MOSFET is enabled and the SS pin is released to allow the soft-start capacitor CSS to charge.
The minimum input voltage is determined by the dropout voltage of the regulator and the VCC UVLO falling threshold (≊ 3.7 V). If VIN is less than ≊ 4 V, the regulator shuts off and VCC goes to zero.