TPS65132 defaults missing?!

Hendrik Funke

Hello,

we are using the TPS65132W in a new project to generate +-5.4V.

Unfortunatly, after building up the board, we're measuring +4V and -4V on the output rails instead of the expectet 5.4V. Is there a possible explanation why the controller sets this minimum values? ENP, ENN, SDA and SCL are tied up to the input voltage (5V) by small resistors.

Thank You for

over 10 years ago

0 Ilona over 10 years ago

TI__Expert 8010 points

Hello Hendrik,

I do not see a reason, why it should generate +-4V instead of +-5.4V. Did you configured the IC as recommended in the EVM ? Can you share the circuit?

thanks

Ilona

www.ti.com/.../tps65132bevm

0 Ilona over 10 years ago in reply to Ilona

TI__Expert 8010 points

Hi Hendrik,

I attached you the wrong EVM, look at this one: www.ti.com/.../slvuab3.pdf

Thanks,
Regards
Ilona

0 Hendrik Funke over 10 years ago in reply to Ilona

Prodigy 70 points

Hello Ilona,

I attached a cutout of the schematic. After powering up the electonic several times and reading out the I2C registers (no writing!), the converter gives now the specified +-5.4V correctly. Can't explain this, but I've had the same behaviour with the second prototype, too.

Thank You

Hendrik

0 Ilona over 10 years ago in reply to Hendrik Funke

TI__Expert 8010 points

Hi Hendrik,

What tolerance do the outputs of +-4V have? Did you append a load on the outputs? Could you measure any curiosity?
If not, can you read the DAC Register? The DAC values for +-5.4V is 0x0E and for +-4V is 0x00, maybe you have switched something here.

Best regards,
ilona

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TPS65132 defaults missing?!