TLV70030 Minimum Load

Arild Pettersen

Hi,

I have a board with a TLV70030DDC regulator. The input voltage to this 3V regulator is regulated and stable 5.0V.

At no load the output voltage from the 3V regulator is higher than the input voltage (>5V). The output voltage seems quite clean on the oscilloscope.

The input capacitors are 3x10uF X7R. The output capacitors are 10uF X7R plus 220uF aluminum electrolytic. The capacitors are very close to the IC.

With a 33k load resistor the output voltage is still >5V.

With a 4k7 load resistor the output voltage is 3.00V.

I have made four boards. Three are ok with no load, and one is bad.

Arild

over 9 years ago

0 Yuanhao Wang over 9 years ago

TI__Prodigy 215 points

Hi Arild,

Due to topology, LDOs are not able to produce an output equal to or higher than the input. Since you have made three boards that work as expected, could it be possible that the fourth board is suffering from leakage due to other causes, e.g. flux?

Very Respectfully,

Yuanhao

0 Arild Pettersen over 9 years ago in reply to Yuanhao Wang

Prodigy 40 points

Thanks, Yuanhao. You are right. The high output voltage was caused by a bad MOSFET.

BR Arild

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TLV70030 Minimum Load