Specifications/limitations for Bandgap Reference design

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ASICK

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Bandgap Reference

for a bandgap reference, the opamp thats required, what should be the major specs/limitations to keep under consideration while designing. I know the offset needs to be low and a high gain, any others??
 

Re: Bandgap Reference

Stability, phase margin? Offset drift with T?
 

Re: Bandgap Reference

PSRR too.
 

Bandgap Reference

power and supply voltage
 

Re: Bandgap Reference

as small as bandwidth to reduce the noise bandwith if the bandgatp is used for low frequency.

To reduce the input referred noise to reduce the noise or offset.

To make the least pole numbers to make the feedback stable.

To reduce the power supply as possible as you can.

To reduce the system offset of op.
 

Re: Bandgap Reference

ASICK said:
for a bandgap reference, the opamp thats required, what should be the major specs/limitations to keep under consideration while designing. I know the offset needs to be low and a high gain, any others??
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To me, the major challenge is the minimum supply voltage in your specification.
If you minimum supply voltage is 5V, then a cascaded current mirror + a voltage mirror is already good enough

Scottie
 

Bandgap Reference

Do we must think about the stability?
 

Bandgap Reference

and we must also consider the temperature effect and supply voltage offset.
 

Re: Bandgap Reference

PSRR, temperature coefficient, temperature scope; stability of many minor loops. start up circuit (the output voltage should be stability before the loweast voltage you descirbed), etc
 

Bandgap Reference

Another important is noise
 

Bandgap Reference

Beside, if it is a two stage amplier with low current consume, you also should decrease some gain (usually more than 80dB is enough for a high psrr), otherwise PM may be not enough.
 

Re: Bandgap Reference

u must think about Line Reg.Load Reg.Temperature Coefficient and loop stability.
 

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