TPS40001: Output voltage is low at low load.

lee 84680

Part Number: TPS40001
Other Parts Discussed in Thread: TPS40007

Hi, I saw TI does not recommend TPS40001 in new design and recommend to use TPS40007.

Why is that? TPS40001 has a problem of output voltage drift depends on load and temperature?

Since I am seeing a problem, TPS40001 may be suspected, output voltage is low at low load and becomes normal at high load.

Please advise, Thanks.

over 8 years ago

0 Mathew Jacob1 over 8 years ago

TI__Expert 5910 points

Soo,

Please take the switching voltage waveform at switch pin at High load and low load. I suspect the output voltage is going high due to DCM mode. What is the input voltage,output voltage and inductor value you are using.

Regards,

Mathew

0 lee 84680 over 8 years ago in reply to Mathew Jacob1

Intellectual 320 points

SW waveforms are jittering at high load, I thought DCM mode happens at light load.
Input voltage : 5V
Output Voltage : 3.3V
Output load : Max 10A
Inductor : 2.7uH
Please comment, Thanks.

0 Mathew Jacob1 over 8 years ago in reply to lee 84680

TI__Expert 5910 points

Soo,
Was there an update on this? Your conditions stated above are not in anyway related to DCM mode. If you can share switch waveforms we can see if there is some other issue.
Regards,
Mathew

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TPS40001: Output voltage is low at low load.