ZHCSCA8A March 2014 – April 2019 TPS65286
PRODUCTION DATA.
Due to the internal design of the TPS65286, there is a minimum output voltage limit for any given input voltage. The output voltage can never be lower than the internal voltage reference of 0.6 V. Above 0.6 V, the output voltage may be limited by the minimum controllable on time. The minimum output voltage in this case is given by Equation 22.
where:
Voutmin = minimum achievable output voltage
Ontimemin = minimum controllable on-time (120 ns maximum)
Fsmax = maximum switching frequency including tolerance
Vinmax = maximum input voltage
Ioutmin = minimum load current
RDS1min = minimum high side MOSFET on resistance (52 mΩ typical
RDS2min = minimum low side MOSFET on resistance (27 mΩ typical)
RL = series resistance of output inductor
For the example circuit, Vin = 24V, Fs = 500 kHz, when Iout = 0 A, the minimum output voltage is 1.44 V