OPA333: Band Gap Reference circuit - Undesirable temperature transient behavior

Kavindu Ratnayake

Part Number: OPA333

Hi,

I'm developing a Band Gap Reference (BGR) circuit around OPA333(Please find the attachment for circuit details). The good news is when the test circuit is subjected to real temperature tests it's having a almost same temperature drift as given by TINA TI simulation. But this is only for steady state. As there are temperature transients (ramps) the BGR output is having large swings before it can stable over the new temperature. Test data is also attached. Currently I'm having the circuit built on a vero board as a prototype(Please find the image of the circuit also)

Anything I can do to get rid of unwanted transient behavior. Any heads up 'd be appreciated

Thanks,

Kavindu

over 7 years ago

0 kai klaas69 over 7 years ago

Guru 140200 points

Hi Kavindu,

it's a well known fact that bandgap references only work properly when all involved transistors are sitting on the same die and always see the exact same temperature. You could use a PNP transistor array for your circuit.

But why not using a ready made bandgap reference chip? This would be much more precise than any self built circuit.

Kai

0 Kavindu Ratnayake over 7 years ago in reply to kai klaas69

Intellectual 350 points

Hello Kai,

Thank you very much for your input.
I'm supposed to develop a voltage reference for Rad- hard(Space) requirement and available ready made Rad-Hard versions (looked so far)are not fitting in to the physical envelop.
Appreciate if you can propose one from your Rad-hard portfolio with small foot print indeed

Best Regards,
kavindu

0 Dennis Goeke over 7 years ago in reply to Kavindu Ratnayake

TI__Genius 11135 points

Kavindu

I did a quick search in our product search, and there are 13 parts in the military/space product lines. Please take a look and see if any of these fit your requirements.
www.ti.com/.../products.html

Regards
Dennis

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OPA333: Band Gap Reference circuit - Undesirable temperature transient behavior