ZHCSFQ9B November 2016 – June 2018 TPS54200 , TPS54201
PRODUCTION DATA.
The PWM pin performs not only the dimming function, but also the enable-and-disable function. When the VIN voltage is above the UVLO threshold, the TPS5420x device can be enabled by driving the PWM pin higher than the threshold voltage, 0.56 V typical. To disable the device, keep the PWM pin lower than the threshold voltage, 0.55 V typical, for 40 ms or longer. The PWM pin has an internal pulldown resistor, so floating this pin disables the device.
The suggested power-on sequence is applying VVINfirst, followed by the PWM signal.