SLUSAE5G August 2011 – April 2021 TPS53355
The TPS53355 is a high-efficiency, single channel, synchronous buck converter suitable for low output voltage point-of-load applications in computing and similar digital consumer applications. The device features proprietary D-CAP™ mode control combined with an adaptive on-time architecture. This combination is ideal for building modern low duty ratio, ultra-fast load step response DC-DC converters. The output voltage ranges from 0.6 V to 5.5 V. The conversion input voltage range is from 1.5 V up to 15 V and the VDD bias voltage is from 4.5 V to 25 V. The D-CAP™ mode uses the equivalent series resistance (ESR) of the output capacitor(s) to sense the device current. One advantage of this control scheme is that it does not require an external phase compensation network. This allows a simple design with a low external component count. Eight preset switching frequency values can be chosen using a resistor connected from the RF pin to ground or VREG. Adaptive on-time control tracks the preset switching frequency over a wide input and output voltage range while allowing the switching frequency to increase at the step-up of the load.
The TPS53355 has a MODE pin to select between auto-skip mode and forced continuous conduction mode (FCCM) for light load conditions. The MODE pin also sets the selectable soft-start time ranging from 0.7 ms to 5.6 ms as shown in Table 7-3.