JAJSH91B April 2019 – January 2020 TPS92613-Q1
PRODUCTION DATA.
The TPS92613-Q1 supports supply control to turn ON and OFF output current. When the voltage applied on the SUPPLY pin is higher than the LED string forward voltage plus needed V(DROPOUT) at required current, and the PWM pin voltage is high, the output current is turned ON and well regulated. However, if the voltage applied on the SUPPLY pin is lower than V(POR_falling), the output current is turned OFF. With this feature, the power-supply voltage in the designed pattern controls the output current ON/OFF. The brightness can be adjustable if the ON/OFF frequency is fast enough. Because of the high accuracy design of PWM threshold in TPS92613-Q1, TI recommends a resistor divider on the PWM pin to set the SUPPLY threshold higher than LED forward voltage plus V(DROPOUT) as shown in Figure 21. When the voltage on the PWM pin is higher than VIH(PWM), the output current is turned ON. However, when the voltage on the PWM is lower than VIL(PWM), the output current is turned OFF.