Semiprecise low voltage low current voltage reference

Aug 02, 2011 3 Replies

Rate this thread:

Klaus Kragelund 14 years ago

I need a voltage reference with the following specs:

Vin = 900mV to 5V Vref = anywhere from 100mV to 900mV, but must be fixed value (max 10% tolerance). So if the reference is 500mV, min/max is 450mV/550mV Reference current = max 10uA

The normal two transistor bandgap with temperature compensation has a nominal value of 1150mV, which is too high since then we need more than 1150mV to operate it.

Been playing with a resistor fed forward biased diode to yield say

300mV. But tempco is 2mV/K, initial tolerance in the range of +/- 25mV due to production spread, combined with no way to provide accurate current for the diode means that this is not a feasable way forward

Googling commercial ICs got me nowhere, minimum 1.2V reference at this low drive current :-(

Anyone got an idea?

Thanks

Klaus

Vote

Spehro Pefhany 14 years ago

There are single-chip options.. eg. LT3008.. or NCP585 (cheaper).

Best regards, Spehro Pefhany

"it's the network..." "The Journey is the reward" speff@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com

Vote

Bill Sloman 14 years ago

And the LM10 might work. It works with a supply voltage down to 1.1V, and includes a 200mV voltage reference. It isn't all that cheap, though the cheaper - 7V max supply voltage - LM10CL sounds as if it would do.

formatting link

Bill Sloman, Nijmegen

Vote

John Larkin 14 years ago

A schottky diode bandgap? Two grounded diodes, run at different currents, and measure the difference, or something like the difference, that gives zero TC.

Of course, there might be details...

John

Vote

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required