Introduction

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1

Introduction

The TPS62125 is a 300-mA, synchronous, step-down converter in a 2x2-mm, 8-pin WSON package.

1.1

Background

The TPS62125EVM-044 (PWR044) uses the TPS62125 device and is set to a 3.3-V output. The EVM

operates with full-rated performance with an input voltage between 4 V and 17 V, assuming JP1 is

connected between ON and EN.

The TPS62125 device contains an adjustable enable threshold and adjustable hysteresis feature. Thus,

the input voltage at which the device enables and disables is fully programmable by the user. In the

TPS62125EVM-044, the device is set to turn on at 6 V and turn off at 4 V. This feature can be bypassed

by using jumper JP1, which overrides the programmed threshold voltages.

1.2

Performance Specification

Table 1 provides a summary of the TPS62125EVM-044 performance specifications. All specifications are

given for an ambient temperature of 25°C.

Table 1. Performance Specification Summary

Specification

Test Conditions

Min

Typ

Max

Unit

Input voltage

JP1 connected between EN and ON

4

17

V

Output voltage

PWM Mode of Operation

3.3

V

Output current

0

300

mA

Peak efficiency

93.3%

Soft-start time

Ramp time of the output voltage

330

µs

1.3

Modifications

The printed-circuit board (PCB) for this EVM accommodates additional input and output capacitors, as well

as a feedforward capacitor.

1.3.1

Input and Output Capacitors

C3 is provided for an additional input capacitor. This capacitor is not required for proper operation but can

be used to reduce the input voltage ripple.

C4 is provided for an additional output capacitor. This capacitor is not required for proper operation but

can be used to reduce the output voltage ripple and to improve the load transient response. The total

output capacitance must remain within the recommended range in the data sheet for proper operation.

1.3.2

Feedforward Capacitor

C6 is provided for a feedforward capacitor. This capacitor is not required for proper operation but can be

used to improve the transient response. Typically, using a 22-pF feedforward capacitor reduces or

eliminates any output voltage overshoot that may occur at start-up. C6 is located on the back side of the

PCB.

2

Setup

This section describes how to properly use the TPS62125EVM-044.

2.1

Input/Output Connector Descriptions

2

TPS62125EVM-044 Evaluation Module

SLVU659A – March 2012 – Revised March 2012

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