JAJSHS0C March 2019 – March 2021 TPS92682-Q1
PRODUCTION DATA
The switch duty cycle, D, defines the converter operation and is a function of the input and output voltages. In steady state, the duty cycle is derived using the expression:
Boost:
Buck-Boost:
The minimum duty cycle, DMIN, and maximum duty cycle, DMAX, are calculated by substituting maximum input voltage, VIN(MAX), and the minimum input voltage, VIN(MIN), respectively in the previous expressions. The minimum duty cycle achievable by the device is determined by the leading edge blanking period and the switching frequency. The maximum duty cycle is limited by the internal oscillator to 90% (typ) to allow for minimum off-time. It is necessary for the operating duty cycle to be within the operating limits of the device to ensure closed-loop regulation over the specified input and output voltage range.