UCD3138: If I offer more than 3.8V supply to UCD3138, is the ADC accuracy bad?

Tina hsieh

Part Number: UCD3138

Hi Experts,

If I offer more than 3.8V supply to UCD3138, how to protect the ADC and DPWM pin?

We want to know when the auxiliary supply offer to UCD3138 out of control, is the ADC accuracy bad to cause no protect to trigger?

Thanks!

over 4 years ago

0 Yitzhak Bolurian over 4 years ago

TI__Mastermind 18370 points

Hi Tina,

The supply voltage to UCD3138 should not exceed 3.8 V.

Over time, higher voltages than 3.8V can have irreversible effect on the integrity of the chip.

0 Tina hsieh over 4 years ago in reply to Yitzhak Bolurian

Prodigy 210 points

Thank you for reply.

Because we design output ovp only use UCD3138 ADC pin, we worry if the ADC accuracy is bad to cause no protection when the auxiliary supply out of control.

SO we want to know if higher voltages than 3.8V, is the ADC accuracy bad?

We need to evaluate whether to add hardware OVP in circuit.

Thanks!

0 Yitzhak Bolurian over 4 years ago in reply to Tina hsieh

TI__Mastermind 18370 points

Hello Tina,

ADC performance may suffer from a supply voltage out of range.

Also OVP using ADC will not be as fast as use of analog comparator for OVP.

If you require an OVP accuracy of better than 3%, you may need to consider another way of OVP implementation.

But as previously mentioned, a supply voltage of more than 3.8V will have other adverse projections.

Regards,

0 Tina hsieh over 4 years ago in reply to Yitzhak Bolurian

Prodigy 210 points

Thank you for reply.

By the way, if higher voltages than 3.8V, is the analog comparator accuracy bad?

Thanks!

0 Yitzhak Bolurian over 4 years ago in reply to Tina hsieh

TI__Mastermind 18370 points

I do not have any data about analog comparator accuracy at supply voltages over 3.8V.

But the resolution of analog comparator reference setting is 7 bits in general.

Regards,

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UCD3138: If I offer more than 3.8V supply to UCD3138, is the ADC accuracy bad?