Current ref. with +/-30% variation

[tdy]

I need a small curent ref ~1ua with +/-30% variation without trim and small standby current 3~5uA. The problem is onchip resistor variation is +/-20% to provide enough margin. Any idea? Tanks in advance.

Regards,

 

[elbadry]

This variation is across what?

process only?
temperature only?
voltage only?

PVT?

 

[tdy]

Thank you for you reply,
Please let me make specific:
I need a small ref current to monitor leakage problems. When chip standby I can't turn it off, the current comsumption is one concern. other specs are:
corner(ss/ff,Res+/-20%)
temp(-40~110)
vdd(1.55~2.1)

 

[jecyhale]

I need a small curent ref ~1ua with +/-30% variation without trim and small standby current 3~5uA. The problem is onchip resistor variation is +/-20% to provide enough margin. Any idea? Tanks in advance.

Regards,

Yes, after you generate the band gap reference voltage, the current is detemined by resistance completely.

Because the referency voltage is a constant.

R varitation can be limted +/-20% with PVT.

 

[tdy]

you mean to do a bandgap,
en......actually i have turned off one bandgap when chip standby, the problem is the power comsumption, i might cant use amplifiers, but it may be one solution. have you met some simple structures to do that?

what is pvt? what is the temperature chara of R with pvt?

 

[jecyhale]

you mean to do a bandgap,
en......actually i have turned off one bandgap when chip standby, the problem is the power comsumption, i might cant use amplifiers, but it may be one solution. have you met some simple structures to do that?

what is pvt? what is the temperature chara of R with pvt?

PVT means process, voltage and temperature.

Ok, but the total current of bandgap including opamp can be designed as low as 1uA, is it too large for you project?

 

[tdy]

I see u point. Thank u very much. How acurrate spice model will be for such small current density ~100nA level from matching point of view?