TIPD107: Can TI suggest something to have 300uA current source

Hi Mehul,

I would go for the "improved Howland current pump":

5873.snoa474a.pdf

Kai

Hello Kai,

Sorry, but I did not get much from the link you have provided. Can you elaborate a bit more? Basically, I want a solution which I can give to my hardware engineer to get desired current out of 300uA.

Mehul

Hi Mehul,

Please provide us design requirements for the 300uA constant current source. As Kai pointed out, it is difficult to suggest something without knowing the actual application. There are over dozen different types of constant current circuit that I can think of. Here is the information that we need to know, if you want to construct 300uA constant current source from discrete precision op amps. 

1. supply voltage for op amp (single or dual supply voltage). 

2. Input voltage for V-I conversion. 

3. Output current (300uA) and accuracy/tolerance (Only current sourcing is required?)

4. Type of load and value: resistive, capacitive or complex load. . 

5. Temperature operating range and/or drift requirements etc. 

In addition, you may choose existing current source ICs to construct your application, see the search link below. For instance, you can use REF200 make up 200uA constant current source. 2 of REF200 can make up 300uA or 400uA constant current source. Or select other ICs to construct 300uA current source. In other words, options are many. 

https://www.ti.com/power-management/voltage-reference/current-reference/products.html?keyMatch=REF200%20EQUIVALENT%20CURRENT%20SOURCE&tisearch=search-everything

Please let us know your V-to-I application.

Best,

Raymond 

Thanks for the feedback :-)

Kai