Low noise inverter chip for biasing GaAs Fet's gate

[nandopg]

inverter chip

I am looking for a low noise inverter chip (8pins) to generate the negative voltage for biasing GaAs Fet's gate.
I tried the Maxim and Linear Technology chips. They performed good but they did'nt accomplish with the temperature range requiride.
Does somebody suggest me some other manufacturer?

Thanks in advance

NandoPG

 

[Bagster]

noise negative voltage

i know quite a few.

for single stage, you can either do this using a custom IC or using discrete components. i am assuming you want to bias at a fixed voltage and with a constant current. what is the gate current, how much do you need. What FET are you using.
If it is low then you can use a crude method. A lm555cm timer configured as a free running oscillator, two diodes an a capacitor or two added to this can generate a unregulated negative voltage. Use a simple BJT set up a circuit that will bias the DUT at a known voltage and current. (if you need a schematic let me know).
Solution 2.
Zetex make asics that do all this for you. There are loads of flavours for every situation.

solution3

NJRC do a device based on the icm7660 switched capacitor invertor. This has two integrated opamps to help set up the bias conditions.

If you need anymore info ask


Regards

Bagster :roll:

 

[shanren]

inverter fet bias

hi,what temp range you request?and how much current do you need?i have used a -40 to 85 degree ,it is a pump converter 7660.many company have such chips,such as maxim,linear tech,national.if the noise is too high,use a rc or lc filter.or use a LDO to get better performance.you can visit:
h**p://www.maxim-ic.com
h**p://www.linear.com
h**p://www.national.com
h**p://www.ti.com
they have many pumps ,even sot23.they also have many LDOs.
hope this can help you.