SLVSD46A November 2017 – December 2021 TPS55160-Q1 , TPS55162-Q1 , TPS55165-Q1
PRODUCTION DATA
To regulate the output voltage at all possible input voltage conditions, the buck-boost converter automatically switches from step-down operation to boost operation and back as required by the configuration. The regulator always uses one active switch, one rectifying switch, one always-on switch, and one always-off switch. Therefore, the regulator operates as a step-down converter (buck) when the input voltage is higher than the output voltage, and as a boost converter when the input voltage is lower than the output voltage. In normal mode, no mode of operation is available in which all four switches are permanently switching. Controlling the switches in this way allows the converter to maintain high efficiency at the most important point of operation; when the input voltage is close to the output voltage. The RMS current through the switches and the inductor is kept at a minimum to minimize switching and conduction losses. For the remaining two switches, one is kept permanently on and the other is kept permanently off which causes no switching losses.
In normal mode, the converter operates in full continuous mode at a fixed switching frequency of 2 MHz (typical) for the entire load-current range, even with no load at the output. No pulse-skipping should occur for supply voltages from 2 V to 27 V.