Easy Howland Current Source
The Difference Amplifiers from a number of vendors can be deployed as a precision current source -- with Linear's LT1990 you only need a sense resistor. However, the LT1990 is also limited to about with f3 of 100kHz. This circuit uses the Analog AD8276 which has an f3 of 550khz -- but requires another resistor. Vin/R1 = I out. In this case, I show 10mA which is about the limit for the AD8276.
Diff amps are great in this application since the resistors are cut with high precision:
Or you can do a boosted current source -- I've done this with the LT1990 -- and the driver transistors are on hand:
|All times are GMT. The time now is 01:35 PM.|
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.
Copyright ©1999-2016 diyAudio