Texas Instruments TPS2640EVM, User Manual

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4.4.3 Current Limit and Fault Responses Test
Follow the instructions to verify the current limit and various fault response modes like auto-retry, latch and circuit
breaker with auto-retry:
1. Set up the oscilloscope as listed in Table 4-8 .
Table 4-8. TPS2640EVM Oscilloscope Setting for the Current Limit Test
Oscilloscope Setting CH1 Probe Points CH2 Probe Points
Channel 1 = 10V / div VOUT1 (TP3) VOUT2 (TP12)
Channel 2 = 10V / div VIN1 (TP2) VIN2 (TP11)
Channel 4 = 2 A / div Input current into T1 +Ve wire Input current into T3 +Ve wire
Trigger source = Channel 2
Trigger level = 12 V ±1V
Trigger polarity = Rising
Trigger mode = Single
Time base 100 ms / div
Note
Measuring the current limit value on the oscilloscope can easily cause ±10% error from the typical
expected values as listed in
Table 4-9 .
2. Set the current limit to 2.23 A by installing the J5/J12 jumper in position 1-2.
3. The jumper setting for different current limits is shown in
Table 4-9 .
4. Set the current limit response to auto-retry by installing the J4/J11 jumper in position 2-3.
Table 4-9. TPS2640EVM Jumper Setting for Current Limits
CH1, CH2 Jumper Positions (J5, J12) Load Current Limit (A)
1-2 2.23
3-4 1.5
5-6 1
7-8 0.2
5. Set the load resistance to 6 Ω ±1 Ω and the power supply voltage to 24 V.
6. Enable the load.
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10 TPS2640EVM: Evaluation Module for TPS2640 SLVUBX9 – OCTOBER 2020
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