Datasheet

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1 Introduction
This user's guide contains background information for the TPS54478 as well as support documentation for
the TPS54478EVM-037 evaluation module (HPA375). Also included are the performance specifications,
the schematic, and the bill of materials for the TPS54478EVM-037.
1.1 Background
The TPS54478 dc/dc converter is designed to provide up to a 4 A output from an input voltage source of
2.95 V to 6 V. Rated input voltage and output current range for the evaluation module are given in
Table 1. This evaluation module is designed to demonstrate the small printed-circuit-board areas that may
be achieved when designing with the TPS54478 regulator. The switching frequency is externally set at a
nominal 1000 kHz. The high-side and low-side MOSFETs are incorporated inside the TPS54478 package
along with the gate drive circuitry. The low drain-to-source on resistance of the MOSFETs allow the
TPS54478 to achieve high efficiencies and helps keep the junction temperature low at high output
currents. The compensation components are external to the integrated circuit (IC), and an external divider
allows for an adjustable output voltage. Additionally, the TPS54478 provides adjustable slow start and
undervoltage lockout inputs. The absolute maximum input voltage is 7 V for the TPS54478EVM-037.
Table 1. Input Voltage and Output Current Summary
EVM INPUT VOLTAGE RANGE OUTPUT CURRENT RANGE
TPS54478EVM-037 VIN = 3 V to 6 V 0 A to 4 A
1.2 Performance Specification Summary
A summary of the TPS54478EVM-037 performance specifications is provided
in Table 2. Specifications are given for an input voltage of V
IN
= 5 V and an
output voltage of 1.8 V, unless otherwise specified. The TPS54478EVM-037 is
designed and tested for V
IN
= 3 V to 6 V. The ambient temperature is 25°C for
all measurements, unless otherwise noted.
Table 2. TPS54478EVM-037 Performance Specification Summary
SPECIFICATION TEST CONDITIONS MIN TYP MAX UNIT
V
IN
operating voltage range 3 5 6 V
V
IN
start voltage 2.90 V
V
IN
stop voltage 2.659 V
Output voltage set point 1.8 V
Output current range V
IN
= 3 V to 6 V 0 4 A
Line regulation I
O
= 2 A, V
IN
= 3 V to 6 V ±0.04%
Load regulation V
IN
= 5 V, I
O
= 0 A to 4 A ±0.15%
Voltage change –54 mV
I
O
= 1 A to 3 A
Recovery time 100 μs
Load transient response
Voltage change 54 mV
I
O
= 3 A to 1 A
Recovery time 100 μs
Loop bandwidth V
IN
= 3.3 V, I
O
= 4 A 79 kHz
Phase margin V
IN
= 3.3 V , I
O
= 4 A 64 °
Input ripple voltage I
O
= 4 A 140 mV
PP
Output ripple voltage I
O
= 4 A <10 mV
PP
Output rise time 3.33 ms
Operating frequency 1000 kHz
Maximum efficiency TPS54478EVM-037, V
IN
= 3 V, I
O
= 0.5 A 94.5%
2
TPS54478EVM-037 4-A, SWIFT™ Regulator Evaluation Module SLVU470–June 11
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