Texas Instruments TPS54290, User Manual

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3.1 Enable Jumpers (JP1 and JP2)
The TPS54291EVM-431 provides separate three pin 100-mil headers and shunts for exercising the TPS54291
Enable functions. Place the JP1 shunt in the left position connects EN1 to ground and turns on Output 1 and
placing the JP2 shunt in the left position connects EN2 to ground and turns on Output 2.
3.2 Error Amplifier Outputs
The output of the TPS54291 transconductance error amplifiers (COMP1 and COMP2) are sensitive to
capacitive loading, including the typical 8-pF to 15-pF capacitance added by an oscilloscope probe. No direct
measurements of these signals should be attempted without using an external buffer to prevent loading of the
control voltage.
3.3 Test Point Descriptions
Table 3-1. Test Point Descriptions
TEST POINT LABEL USE SECTION
TP1 VIN Monitor Input Voltage Section 3.3.1
TP2 GND Ground for Input Voltage Section 3.3.1
TP3 VOUT1 Monitor VOUT1 Voltage Section 3.3.2
TP4 GND Ground for VOUT1 Voltage Section 3.3.2
TP5 GND Ground for VOUT1 Channel B Loop Monitoring Section 3.3.3
TP6 CHB VOUT1 Channel B for Loop Monitoring Section 3.3.3
TP7 GND Ground for VOUT1 Channel A Loop Monitoring Section 3.3.3
TP8 CHA VOUT1 Channel B for Loop Monitoring Section 3.3.3
TP9 SW1 Monitor Switching Node of Channel 1 Section 3.3.4
TP10 GND Ground for Switch Node of Channel 1 Section 3.3.4
TP11 IC_GND Monitor IC Ground Section 3.3.5
TP12 SW2 Monitor Switching Node of Channel 2 Section 3.3.6
TP13 GND Ground for Switch Node of Channel 2 Section 3.3.6
TP14 CHA VOUT2 Channel A for Loop Monitoring Section 3.3.7
TP15 GND Ground for VOUT2 Channel A Loop Monitoring Section 3.3.7
TP16 CHB VOUT2 Channel B for Loop Monitoring Section 3.3.7
TP17 GND Ground for VOUT2 Channel B Loop Monitoring Section 3.3.7
TP18 VOUT2 Monitor VOUT2 Voltage Section 3.3.8
TP19 GND Ground for VOUT2 Voltage Section 3.3.8
3.3.1 Input Voltage Monitoring (TP1 and TP2)
TPS54291EVM-431 provides two test points for measuring the voltage applied to the module. This allows the
user to measure the actual module voltage without losses from input cables and connectors. All input voltage
measurements should be made between TP1 and TP2. To use TP1 and TP2, connect a voltmeter positive
terminal to TP1 and negative terminal to TP2.
3.3.2 Channel 1 Output Voltage Monitoring (TP3 and TP4)
TPS54291EVM-431 provides two test points for measuring the voltage generated by the module. This allows
the user to measure the actual module output voltage without losses from output cables and connectors. All
output voltage measurements should be made between TP3 and TP4. To use TP3 and TP4, connect a voltmeter
positive terminal to TP3 and negative terminal to TP4. For output ripple measurements, TP3 and TP4 allow a
user to limit the ground loop area by using the tip and barrel measurement technique shown in
Section 4.2.2 .
All output ripple measurements should be made using the tip and barrel measurement. Even this Tip and Barrel
measurement technique increases the measured switch edge noise. For improved output ripple measurement,
measure the output ripple at the output capacitor (C5).
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SLVU356A – JANUARY 2010 – REVISED OCTOBER 2021
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