TL431

eli

Guru 13485 points

Other Parts Discussed in Thread: TLV431, TL4051A, LM4041B, TL431

We design a voltage reference circuit with the TLV431 as
in the follow diagram:

While maintain DAC_VBL to the minimum tolerance, the TLV431BI induce large error for our implementation

Can you please suggest a more accurate shunt with same/samaller package?

Thanks

over 10 years ago

0 Ron Michallick over 10 years ago

TI__Guru**** 164956 points

Eli,

At what DAC_VBL voltage does VBL regulate poorly?

TL4051A and LM4041B have higher accuracy options.
However these shunts are common cathode (Vref is Vcathode-Vref)

0 eli over 10 years ago in reply to Ron Michallick

Guru 13485 points

Hi Ron

The accuracy getting worse when going from 1.575V(~5%) to 1.896V (~7%) but the starting point is the 1.53% (1.259V) max error of the hunt.

0 Ron Michallick over 10 years ago in reply to eli

TI__Guru**** 164956 points

Eli,

Check for oscillation at output.
Is the 10uF capacitor ceramic? This would add an output pole without a useful zero.
The TL431 already has an internal pole. With two poles, the loop may be unstable.

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TL431