Low current voltage reference

Hello, Andrew -

I would look at the LT1460-2.5 from Linear Technology. It consumes a maximum of 165uA quiescent current. Other possibilities include the LM4140, LM4125 and the LM4132 from National Semiconductor. the LM4132 is especially interesting with a maximum 100uA quiescent current.

- Nichkolas "Nick" Gray

Another one for you to consider...

Microchip MCP1525-I/TO    2.5V ref 

Farnell Order Code: 1292235

Linear tech 1790 http://www.linear.com/pc/productDetail.jsp?navId=H0,C1,C1154,C1002,C1804,P1865

I would recommend using a voltage reference IC. This is the standard technique used for producing a stable accurate reference voltage for Analog-to-Digital Conversion (ADC).

Note that voltage references are not the same as a voltage regulator, in that references tend to only produce a low usable current (less than 100mA), making them largely unsuitable to power a general circuit.

Here are some general links to articles about voltage references:

• A Quick Guide to Voltage References (Maxim App Note 1182)
• Voltage References Hold Steady (EDN Paul Rako, 21 Oct 2010)

As you are looking for one with low power / current demands, a 3-terminal Band-gap (series) voltage reference would be a good place to start. Otherwise Floating-Gate-Array (FGA) voltage references such as from Intersil (who acquired Xicon) would also have low quiescent current suitable for battery powered applications.

If you want to know a bit more about topologies and technical differences

• Understanding voltage references topologies and specifications (Maxim App Note 719)
• Series of Shunt Reference? (Maxim App Note 4003)

Two short articles written by Texas Instruments' Bonnie Baker in EDN on getting sufficient accuracy from a voltage reference in an ADC circuit (in other words, how to use them correctly).

• Absorb current spikes and noise with a simple technique (EDN page 22; 21 Oct 2010)
• Go for the gold with voltage-reference circuits (EDN page 18; 18 Nov 2010)

I think that a voltage reference IC is the best choice. Recently, I used REF3025 from Texas Instruments to produce a 2.5V reference voltage for an ADC converter.

It features a low quiscient current (50 uA max), a low dropout voltage and a high output current (25 mA).

I'm using adjustable references from maxim 61' serie ( if You would need to change voltage ) and LTC6652-2.5 as a reference for ADC.