LM134: Using the LM334 current source in device meant for -40°C to 80°C operating temperatures.

Hi, 

I am currently working on a design that has an operating temperature spec of -40°C to  +80°C. 

For this design I need to use a current source to get a 5µA current. For testing purposes I used the LM334 but later realised that its operating temperature is only 0°C to 70°C. 

I would like to start by asking if I can use the LM334 for this application or do I need to switch to the LM134. 

my next question is do you have an alternate to the LM134 that is a SMD package and has the correct operating temperature

Kind regards