LM334: LM4132: Load Independent 5mA constant current source (Load Resistance 650 ohm to 750 ohm).

Rajesh Matere

Part Number: LM334
Other Parts Discussed in Thread: LM4030, LM4132

Hi,

We are looking for Load Independent constant current source, Load current value will be 5mA. Load resistance will vary from 650 Ohm to 850 Ohm. Input power is 5V.

Also, it should have lower temperature coefficient, because this is going to be implemented in Sensor application.

I do have size constraint on board, so I am looking for less component solution.

I experimented the same with LM334, but output current is varying with changing load resistance. Tested schematics are attached here.LM334 Based_ Current Source Design.pdf

Can we use LM334 as (Load independent) constant current in such kind of application?

Thank you,

Regards,

Rajesh Matere.

over 6 years ago

0 Marcoo Z over 6 years ago

TI__Mastermind 19550 points

Hi Rajesh,

You can use this as a load independent current source but it would have to be case 2 to have some sort of external compensation for its temp co.
The LM334 is a very old device and I would prefer to use a series reference like the LM4132 (as in your other thread) for a more precise current source or a LM4030/40/50 type of device with an amplifier.

-Marcoo

0 Rajesh Matere over 6 years ago in reply to Marcoo Z

Prodigy 205 points

Hi Marcoo,

Thanks for your valuable feedback.

Regards,
Rajesh M

Power management

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LM334: LM4132: Load Independent 5mA constant current source (Load Resistance 650 ohm to 750 ohm).