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1.2 Performance Specification Summary
1.3 Modifications
R2  10 k 
0.891 V
V
O
 0.891 V
(1)
Introduction
low drain-to-source on resistance of the MOSFET allows the TPS54550 to achieve high efficiencies and
helps to keep the junction temperature low at high output currents. An external divider allows for an
adjustable output voltage. External compensation components accommodate a wide range of output filter
components. Additionally, the TPS54550 provides an enable input. The absolute maximum input voltage
is 20 V.
Table 1. Input Voltage and Output Current Summary
EVM INPUT VOLTAGE RANGE OUTPUT CURRENT RANGE
TPS54550EVM-158 VIN = 6 V to 17 V 0 A to 5 A
A summary of the TPS54550EVM-158 performance specifications is provided in Table 2 . Specifications
are given for an input voltage of VIN = 12 V and an output voltage of 3.3 V, unless otherwise specified.
The TPS54550EVM-158 is designed and tested for VIN = 6 V to 17 V. The ambient temperature is 25°C
for all measurements, unless otherwise noted. Maximum input voltage for the TPS54550EVM-158 is 20 V.
Table 2. TPS54550EVM-158 Performance Specification Summary
SPECIFICATION TEST CONDITIONS MIN TYP MAX UNIT
VIN voltage range 6 12 or 15 17 V
Output voltage set point 3.3 V
Output current range V
IN
= 10 V to 17 V 0 5 A
Line regulation I
O
= 0 2.5 A, VIN = 10 V - 17 V +0.08 %
-0.03
Load regulation VIN = 12 V, I
O
= 0 A to 5 A +0.07 %
-0.01
Load transient response Voltage change I
O
= 1.25 A to 3.75 A -72.5 mV
Recovery time 450 µ s
Voltage change I
O
= 3.75 A to 1.25 A +72.5 mV
Recovery time 450 µ s
Loop bandwidth VIN = 12 V, I
O
= 2.5 A 27 kHz
Phase margin VIN = 12 V, I
O
= 2.5 A 62 °
Input ripple voltage VIN = 7 V, I
O
= 5 A 276 300 mVpp
Output ripple voltage VIN = 7 V, I
O
= 5 A 7 mVpp
Output rise time 5 ms
Operating frequency 700 kHz
Max efficiency VIN = 6 V, V
O
= 3.3 V, I
O
= 1.25 A 93.5%
The TPS54550EVM-158 is designed to demonstrate the small size that can be attained when designing
with the TPS54550. A few changes can be made to this module.
1.3.1 Output Voltage Set Point
To change the output voltage of the EVM, it is necessary to change the value of resistor R2. Changing the
value of R2 can change the output voltage above 0.891 V. The value of R2 for a specific output voltage
can be calculated using Equation 1 .
Table 3 lists the R2 values for some common output voltages. Note that VIN must be in a range so that
the minimum on-time is greater than 220 ns, and the maximum duty cycle is less than 80%. The values
given in Table 3 are standard values, not the exact value calculated using Equation 1 .
TPS54550EVM-158 SWIFT™ Regulator Evaluation Module2 SLVU151 – March 2006
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