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1 Introduction
This User's Guide contains background information for the TPS54678 as well as support documentation
for the TPS54678EVM-155 evaluation module (EVM) (PWR155). Also included are the performance
specifications, the schematic, and the bill of materials for the EVM.
1.1 Background
The TPS54678 dc/dc converter is designed to provide up to a 6-A output from an input voltage source of
2.95 V to 6 V. Rated input voltage and output current range for the EVM are given in Table 1. This EVM
demonstrates the small printed-circuit board areas that are achieved when designing with the TPS54678
regulator. The switching frequency is externally set at a nominal 500 kHz. The high-side and low-side
MOSFETs are incorporated inside the TPS54678 package along with the gate-drive circuitry. The low
drain-to-source on resistance of the MOSFETs allow the TPS54678 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
TPS54678 provides adjustable slow start and undervoltage lockout inputs. The absolute maximum input
voltage is 7 V for the EVM.
Table 1. Input Voltage and Output Current Summary
EVM INPUT VOLTAGE RANGE OUTPUT CURRENT RANGE
TPS54678EVM-155 V
IN
= 3 V to 6 V 0 A to 6 A
1.2 Performance Specification Summary
A summary of the EVM performance specifications is provided in Table 2. Specifications are given for an
input voltage of V
IN
= 5 V and an output voltage of 1.2 V, unless otherwise specified. The EVM 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. TPS54678EVM-155 Performance Specification Summary
PARAMETER TEST CONDITIONS MIN TYP MAX UNITS
INPUT CHARACTERISTICS
Operating voltage range 3 5 6 V
V
IN
start voltage V
V
IN
stop voltage V
OUTPUT CHARACTERISTICS
Output voltage, V
OUT
Output current = 0 to 6A 1.2 V
Output load current, I
OUT1
I
OUT_min
to I
OUT_max
0 6 A
Line Regulation: Input voltage = 3 V to 6 V 0.5%
Output voltage regulation
Load Regulation: Output current = 0 A to I
OUT_max
0.5%
Peak voltage 60 mV
I
OUT
= 3 A to 6 A and
Transient response
6 A to 3 A
Recovery time 200 µs
Output voltage ripple V
IN
= 5 V, I
OUT
= 6 A mVpp
Output over current 10 A
SYSTEMS CHARACTERISTICS
Switching frequency F
SW
500 kHz
Control loop bandwidth V
IN
= 3.3 V, I
O
= 6 A kHz
Phase Margin V
IN
= 3.3 V, I
O
= 6 A Degrees
Input ripple voltage mVp-p
Soft start time mSec
Peak efficiency V
IN
= V, I
OUT
= A %
Full load efficiency V
IN
= V, I
OUT
= 6 A %
Operating temperature T
oper
25 ºC
2
TPS54678EVM-155 6-A, SWIFT™ Regulator Evaluation Module SLVU747–June 2012
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