TLV61224: Vin = Vout, Don't Know What Im Doing Wrong

Robert S

Part Number: TLV61224

Hi, I'm using this chip tlv61224 to obtain a constant power output supply of 3.0V out of two AA batteries. The load is about 20mA. I'm wiring this chip as stated in page 1 of the datasheet "Typical Application Schematic". No matter what the input voltage is the output voltage is the same. If Vin = 2.1V then Vout = 2.1V and so on. I'm pulling my hair out with this one. Any help is greatly appreciated. Thanks, Robert.

over 6 years ago

0 Minqiu Xie over 6 years ago

TI__Mastermind 21565 points

Hi Roberto:

Thanks for asking.

Have you checked if it caused by soldering? May you share the schematic and layout for me? It's better if you could catch the Vin, Vout, L and EN

0 Minqiu Xie over 6 years ago in reply to Minqiu Xie

TI__Mastermind 21565 points

Hi Roberto:

How is it going? Is there any updating?

0 Robert S over 6 years ago in reply to Minqiu Xie

Intellectual 550 points

Hi Minqiu,

I'll update soon. I'm out of town now. Thanks.

0 Robert S over 6 years ago in reply to Minqiu Xie

Intellectual 550 points

Hmm, I was using a diode at Vin to prevent the user from burning the booster by putting the batteries backwards. If I remove the diode, I get 3V at Vout. How do I prevent the tlv61224 from burning if the customer puts the batteries backwards? I already burned one booster intentionally, by putting the batteries backwards.

0 Minqiu Xie over 6 years ago in reply to Robert S

TI__Mastermind 21565 points

Hi Roberto:

So there is two issue:

1. With the diode, the converter couldn't work as expected.

For this, please catch the waveform of Vin, Vout, L and EN pin. ( The test point should near the IC.)

I afraid the Vin is not 2.1V anymore during the load.

2. Without the diode, the system may be damaged.

The minimum voltage for the pin of IC is -0.3V. So it does need reverse voltage protection.

0 Minqiu Xie over 6 years ago in reply to Minqiu Xie

TI__Mastermind 21565 points

Hi Roberto:

As long time not hear you, I assume you have solved the issue. I'll close this post.

If need further support, just reply below. Thank you~

0 Robert S over 6 years ago in reply to Minqiu Xie

Intellectual 550 points

Hi Minqiu,

What would be the best "reverse voltage protection"? Can you please elaborate? A diode?

Robert

0 Minqiu Xie over 6 years ago in reply to Robert S

TI__Mastermind 21565 points

Hi Robert:

Yes, with a diode in series. Is there any machine design to avoid the reverse of battery?

0 Robert S over 6 years ago in reply to Minqiu Xie

Intellectual 550 points

Thanks. That resolves my issue.

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TLV61224: Vin = Vout, Don't Know What Im Doing Wrong