Texas Instruments TPS25921XEVM-637, User Manual

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General Configurations
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4.3.1 Test Procedure
Use the following steps to test the EVM:
1. Set the power-supply output VIN to 0 V.
2. Turn on the power supply and set the output voltage and current limit according to Table 5 .
Table 5. Power Supply Setting for PWR637
Power Supply Current
EVM Channel Voltage Set Point
Limit
CH1(J1)
PWR637 12 ±0.2 VDC 3 A ±0.25 ADC
CH2(J5)
3. Turn off the power supply. Hook up CH1 and CH2 of the PWR637 assembly as shown in Figure 2 .
4. The default EVM jumper setting is shown in Table 6 .
Table 6. Default Jumper Setting for PWR637
J3 (CH1) J7 (CH2) J4 (VOUT1)
2-3 2-3 2-3
5. CH1 and CH2 can be tested one by one for PWR637.
6. Ensure that the output load is disabled and the power supply is set properly for the design under test
(DUT). Connect the negative probe of DMM to TP1, TP7, TP12, or TP13 (GND). Turn on the power
supply, and verify that the voltages shown in
Table 7 are obtained.
Table 7. PWR637 DMM Readings at Different Test Points
Voltage Test on
Voltage Test on (CH1) Measured Voltage Reading Measured Voltage Reading
(CH2)
VIN1 (TP6) 12 ±0.5 VDC VIN2 (TP19) 12 ±0.5 VDC
EN1 (TP3) 3.84 ±0.3 VDC EN2 (TP16) 3.84 ±0.3 VDC
OVP1 (TP22) 0.988 ±0.2 VDC OVP2 (TP23) 0.988 ±0.2VDC
VOUT1 (TP5) 12 ±0.5 VDC VOUT2 (TP16) 12 ±0.5 VDC
FLTb1 (TP4) 10.6 ±0.6 VDC FLTb2 (TP17) 10.6 ±0.6VDC
0.451 ±0.1 VDC (for J7 jumper in
0.451 ±0.1 VDC (for J3 jumper in 2-3)
2-3)
ILIM1(TP10) 1 ±0.1 VDC (for J3 jumper in 1-2 ) ILIM2(TP20) 1 ±0.1 VDC (for J7 jumper in 1-2 )
1.43 ±0.15 VDC (for no jumper in
1.43 ±0.15 VDC (for no jumper in J3)
J7)
4.3.1.1 CH1 (J1)
Use the following steps to test CH1 (J1).
1. Press the EVM RST switch, S1, and verify that the voltage at VOUT1 (TP5) starts falling slowly below
12 V and the FLTb1 red LED (D3) turns ON. Release S1.
2. Reduce the input voltage on VIN1 and monitor VOUT1. Verify that VOUT1 (TP5) starts falling and is
fully turned off when VIN1 (TP6) reaches 4.2 V (M 0.3 V). Verify that the FLTb1 red LED (D3) turns
ON.
3. Adjust the power supply voltage to 12 V.
4. Increase the input voltage on VIN1 and monitor VOUT1. Verify that VOUT1 (TP5) starts increasing and
then turns off when VIN1 (TP6) exceeds 17 V (M 1 V). Verify that the FLTb1 red LED (D3) turns ON.
5. Adjust the power supply voltage to 12 V.
6. Turn off the power supply.
8 TPS25921X-637EVM: Evaluation Module for TPS25921X SLUUB50 – August 2014
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