opa827: OPA827 current noise density

Greg Leeson

Prodigy 120 points

Part Number: OPA827
Other Parts Discussed in Thread: TINA-TI,

Is there a plot available for current noise density vs frequency?

over 7 years ago

0 Marek Lis over 7 years ago

TI__Guru 65040 points

Greg,

Since the input current noise spectral density is a function of the input bias current (Inoise=sq-rt(2*q*IB), in the case of CMOS and JFET (OPA827) input op amps it is very small and thus in most cases may be neglected. However, you may still simulate it using our Tina-TI macro-model available on our website - see below. The increase in the Inoise above f=100kHz as shown in the graph below is caused by the interaction of the input capacitance and open-loop output impedance. I have attached the simulation file for your own simulation.

OPA827 Noise.TSC

0 Greg Leeson over 7 years ago in reply to Marek Lis

Prodigy 120 points

No 1/f component?

0 Marek Lis over 7 years ago in reply to Greg Leeson

TI__Guru 65040 points

In CMOS and JFET input amplifiers like OPA827 there is 1/f component in the input voltage noise spectral density but no 1/f in the input current noise spectral density.

0 Greg Leeson over 7 years ago in reply to Marek Lis

Prodigy 120 points

Very interesting, I didn't know that, thank you.

Amplifiers

Amplifiers forum

opa827: OPA827 current noise density