TIDUEU6B September 2020 – December 2021 OPA810
The OPA2810 is a dual-channel, FET-input, voltage-feedback operational amplifier with low input bias current of 2 pA. The extremely low input bias current is very useful in this application because this current will flow through unknown impedance which can go high as 10 MΩ. OPA2810 is unity-gain stable with a small-signal unity-gain bandwidth of 105 MHz, and offers excellent DC precision and dynamic AC performance at a low quiescent current. This device has a DC open loop gain equal to 120 dB. With a gain-bandwidth product (GBW) of 70 MHz, the OPA2810 has Aol greater than 60 dB at all the frequencies less 100 kHz. The high Aol of the op amp reduces the error in measurement because as the Aol increases the voltage at the inverting input approaches to zero. Thus, this is very important specification of this device to make it well suited for use in this application. The supply voltage of OPA2810 can go up to +/- 13.5 V. This high voltage operation provides optimal distortion performance in the LCR meter signal chain. The voltage noise of this amplifier is 6 nV/√Hz.