The heater driver in the old design (iLIGO PSL) is this horrible programmable power supply with high output noise (see measurement of 40m PSL heater).

What we want instead is something that takes in +/- 10 V and drives a DC current (not PWM) into our heaters (which are ~50-100 Ohms). A BUF634 is almost good enough; it can do 200 mA at 10 V. Is there a BUF634 equivalent which can do more like 500 mA? Otherwise we can just use a opamp + transistor.

What is being used for the ring heaters at the LIGO sites?