Dear support team,
I would like to use the BIAS current source as a fixed DC current source, i.e whithout using the regulation loop. The resistor connected to the pin IBMAX should set the value of the current, according to fig.15 from data sheet.
To have this functionnality, I have done the following steps, according to data sheet:
- connected APCSET pin to VCC with a 100 kOhm resistor
- let PD floatting.
- connected a 220n capacitor between pin CAPC and GND
- set i.e a 22kOhm resistor between pin IBIAS and VCC to get about 15 mA on BIAS
Unfortunately, I experience an oscillation on the BIAS current at a few MHz with this set-up. Removing the capacitor on CPAC do not change things.
Can you recommend an other set-up to operate the BIAS current source in open loop?