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1 Introduction
This user’s guide contains background information for the TPS54225 as well as support documentation for the
TPS54225EVM-538 evaluation module. Also included are the performance specifications, schematic and the bill
of materials for the TPS54225EVM-538.
1.1 Background
The TPS54225 is a single, adaptive on-time D-CAP2
™
mode synchronous buck converter requiring a very
low external component count. The D-CAP2 control 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 700 kHz. The high-side and low-side switching MOSFETs
are incorporated inside the TPS54225 package along with the gate drive circuitry. The low drain-to-source on
resistance of the MOSFETs allows the TPS54225 to achieve high efficiencies and helps keep the junction
temperature low at high output currents. The TPS54225 DC/DC synchronous converter is designed to provide
up to a 2-A output from an input control voltage source of 4.5 V to 18 V and an input power voltage source of 2
V to 18 V. The output voltage range is from 0.76 V to 5.5 V. Rated input voltage and output current range for the
evaluation module are given in
.
The TPS54225EVM-538 evaluation module is a single synchronous buck converter providing 1.05 V at 2 A from
5-V to 17-V input. This user’s guide describes the TPS54225EVM-538 performance.
Table 1-1. Input Voltage and Output Current Summary
EVM
INPUT VOLTAGE RANGE
OUTPUT CURRENT RANGE
TPS54225EVM-538
VIN = 4.5 V to 17 V
0 A to 2 A
1.2 Performance Specification Summary
A summary of the TPS54225EVM-538 performance specifications is provided in
. Specifications are
given for an input voltage of VIN = 12 V and an output voltage of 1.05 V, unless otherwise noted. The ambient
temperature is 25°C for all measurement, unless otherwise noted.
Table 1-2. TPS54225EVM-538 Performance Specifications Summary
SPECIFICATIONS
TEST CONDITIONS
MIN
TYP
MAX
UNIT
Input voltage range (VIN)
4.5
12
17
V
CH1
Output voltage
1.05
V
Operating frequency
VIN = 12 V, I
O
= 1 A
700
kHz
Output current range
0
2
A
Over current limit
VIN = 12 V
3.1
A
Output ripple voltage
VIN = 12 V, I
O
= 2 A
7
mV
PP
1.3 Modifications
These evaluation modules are designed to provide access to the features of the TPS54225. Some modifications
can be made to this module.
1.3.1 Output Voltage Set Point
To change the output voltage of the EVMs, it is necessary to change the value of resistor R1. Changing the
value of R1 can change the output voltage above 0.765 V. The value of R1 for a specific output voltage can be
calculated using
For output voltage from 0.76 V to 2.5 V:
R1
VO = 0.765
1+
R 2
æ
ö
´ ç
÷
è
ø
(1)
For output voltage over 2.5 V:
Introduction
2
TPS54225 Step-Down Converter Evaluation Module User's Guide
SLVU337A – NOVEMBER 2009 – REVISED OCTOBER 2021
Copyright © 2021 Texas Instruments Incorporated