LM334: Current source design working below 1 µA

Federico Belotti

Part Number: LM334

Hello,

I'm working on a project review where the LM334 works as current source to bias a resistive sensor.

I'm checking several kind of new sensors, and due to the various device application parameters (and limitations), in some cases I find the LM334 working at ISet values below 1 µA, also around 0.3 µA.

Any advice or warnings about this issue?

Thank you in advance,

Federico

over 5 years ago

0 Michael_DeSando over 5 years ago

TI__Genius 12630 points

Federico,

Operating outside of the recommended operating range may hinder the Electrical Characteristics specs such as Set current error for example. What is the Vin voltage and Rset value for your circuit?

0 Federico Belotti over 5 years ago in reply to Michael_DeSando

Prodigy 80 points

Hello Michael,

thank you for your reply.

Vin voltage +5V

Rset ranges from 120K Ohms to 220 KOhms; it can be varied by a digital potentiometer.

Federico

0 Marcoo Z over 5 years ago in reply to Federico Belotti

TI__Mastermind 19580 points

Hi Federico,

Because this device was not tested below 1uA on the datasheet so we cannot guarantee its performance and so we cannot recommend its use below 1uA.

How much accuracy do you need? There is discrete implementations.

-Marcoo

Power management

Power management forum

LM334: Current source design working below 1 µA