SLVSG70 april 2023 TPS62902-Q1
PRODUCTION DATA
The duty cycle of the buck converter operating in PWM mode is given as D = VOUT / VIN. The duty cycle increases as the input voltage comes close to the output voltage and the off time gets smaller. When the minimum off time of typically 80 ns is reached, the TPS62902-Q1 scales down its switching frequency while it approaches 100% mode. In 100% mode, the device keeps the high-side switch on continuously. The high-side switch stays turned on as long as the output voltage is below the internal set point, allowing the conversion of small input to output voltage differences (for example, getting longest operation time of battery-powered applications). In 100% duty cycle mode, the low-side FET is switched off.
The minimum input voltage to maintain output voltage regulation, depending on the load current and the output voltage level, can be calculated as:
where