SLVSFH6C January 2021 – December 2021 TPS61094
The TPS61094 has the peak current limit in Buck mode and valley current limit in Boost mode. Current limit detection occurs when the high-side MOSFET turns on.
In Buck mode, the TPS61094 has average output current control, so the current limit in Buck mode is hard to reach.
In Boost mode, when the load current is increased such that the inductor current is above the current limit within the whole switching cycle time, the off time is increased to allow the inductor current to decrease to this threshold before the next on time begins (called the frequency foldback mechanism). When the current limit is reached, the output voltage decreases during further load increase.
The maximum continuous output current (IOUT(LC)), before entering current limit (CL) operation, can be defined by Equation 1.
The duty cycle can be estimated by Equation 2.
The peak-to-peak inductor ripple current is calculated by Equation 3.