SLVU641A
January 2012 – November 2021
TPS54120
Trademarks
1
Background
2
Setup
2.1
Input and Output Connections and Jumper Descriptions
2.2
Modifications
2.2.1
SW Output Voltage Setpoint
2.2.2
LDO Output Voltage Setpoint
2.2.3
Switcher Slow-Start Time
2.2.4
LDO Start-Up
2.3
Equipment Interconnect
3
Operation
4
Test Results
4.1
Output Voltage Ripple
4.2
Output Noise
4.3
Output Turn-On
4.4
Load Transient
4.5
Efficiency
4.6
Thermal Characteristic
5
Board Layout
5.1
Layout Description
6
Schematic
7
Bill of Materials
8
Revision History
3
Operation
Turn on the input power supply. Verify that the switcher output voltage is near 4.1 V and the LDO output is near 0 V.
Enable the LDO output by connecting the jumper on JP1 from the “on” pin to the center pin (LDO EN).
Verify that the LDO output voltage is 3.3 V.
Vary the load current and V
IN
voltage as necessary for test purposes.