SLIS178B October 2017 – January 2018 TPS92830-Q1
In the case of supply dimming, the supply of the whole LED driver module is PWM dimmed, for example by body-control-module (BCM) high-side switches. The TPS92830-Q1 device supports supply dimming with a short power-on delay. Device supply VIN should be always equal to V(ISP) to ensure that the charge pump voltage is high enough to turn on the MOSFET.
When supply dimming is used, it is recommended to be used together with PWM input, so that the channel is only turned on when the input voltage is above the device UVLO threshold. By keeping enough delay time between device power up and channel turnon, output current spikes can be avoided to ease EMC design.