Rev.1.1

http://www.elm-tech.com

4

10 -

ELM852xA common mode input voltage range is fixed under the condition of CMRR≥45dB; ELM852xA

is able to accept the input above its specification if the degradation of CMRR is not considered. Even if the

input voltage exceeds either positive or negative power voltage, troubles such as reverse of output will not

occur.

As maximum absolute rating, the input voltage is possible within (Vss-0.3)V to (Vdd+0.3)V.

1) Common mode input voltage range

■Note

When OP-AMP circuit is used with feedback resistor, oscillation may happen in the circuit with loop-gain

like unity gain follower.

a) When large feedback resistance is used, the phase margin is decreased by its combination with the

parasitic capacitance of the input part of OP-AMP. In this situation, please connect small capacitor in

parallel with feedback resistor as shown in fig-1.

b) For capacitive load, external resistor in series connection will be effective as shown in fig-2.

(RL=300 to 500Ω)

c) Being used as an unity gain follow, ELM852xA is able to drive capacitive load of 100pF directly without

oscillation.

2) Operation from single power source

ELM852xA is designed to be most suitable for single power source; therefore, ELM852xA is able to share

power supply with logic circuit one. Meanwhile, ELM852xA can also operate from double power sources.

To protect power supplies of ELM852xA and logic circuit from noise, please separate wire from power

supply and use decoupling (bypass) capacitor. Using the capacitor can improve PSRR characteristics,

especially on 10kHz to 100kHz or more.

3) Feedback

a) fig-1

b) fig-2