1 Introduction

In light-load conditions, the TPS563252 operates in Eco-mode to enable higher efficiency by varying its switching frequency, and the TPS563257 operates in FCCM to maintain constant switching frequency. The main difference is at light loading, but the other behaviors are similar. This user's guide mainly introduces the TPS563252 and includes some TPS563257 features that are different from the TPS563252.

The TPS56325x is a single, adaptive on-time, D-CAP3™ control mode, synchronous buck converter that requires a very low external component count. The D-CAP3 control mode circuit is optimized for low-ESR output capacitors such as POSCAP, SP-CAP, or ceramic types and features fast transient response with no external compensation. The switching frequency is internally set at a nominal 1.2 MHz. The high-side and low-side switching MOSFETs are incorporated inside the TPS56325x package along with the gate-drive circuitry. The low drain-to-source on resistance of the MOSFETs and fast switching slew rate allow the TPS56325x to achieve high efficiency and help keep the junction temperature low at high output currents. Power sequencing is possible by correctly configuring the enable and power-good indicator. The TPS56325x DC/DC synchronous converter is designed to support up to a 3-A continuous current from an input voltage source of 3 V to 17 V. The output voltage range is from 0.6 V to 10 V. Rated input voltage and output current ranges for the evaluation module are given in Table 1-1.

The TPS563252EVM evaluation module (EVM) is a single, synchronous buck converter providing 1.05 V at 3 A from 3-V to 17-V input. This user’s guide describes the TPS563252EVM performance.