Looking for Help! PCI 6723 output a wrong voltage

[johnsold]

Ohm's law: 6 V/50 ohms = 120 mA >> 30 mA!

You will need to use a high current buffer type amplifier. Standard op amps cannot produce 30 mA and certainly not 120 mA. I will see if I can come up with a device which might work later.

Lynn

[AnalogKid2DigitalMan]

I think some of Linear's op-amps can output Amps of current like the LT-1210.

http://www.linear.com/products/high_output_current_amplifiers

I remember long ago but can recall the make/model of an op-amp that could source ~10A.

(EDIT- just found it BB's OPA Series, now sourced by TI?)

http://www.ti.com/product/opa541

-AK2DM

[johnsold]

Thanks.

The OPA544 might be a good choice. Some of the LT devices have very wide bandwidth and preventing high frequency oscillations can be a problem.

Lynn

[YoungHang]

   I am sorry about that it is my fault that I did not say it clearly that the maximum voltage for the 50 Ω load was just 1V, while the 6V is for other loads with high resistance value. So actually 30mA is ok for me, but the common-mode input voltage range of the op should at least -6 to +6V, and the output voltage range should be ! With other's help, I found the ADA4898-1 from Analog Devices.

  Thank you all!