ELM832 Datasheet, PDF (4/10 Pages) ELM Technology Corporation – 20μA Low power CMOS operational amplifier

ELM832xC 20μA Low power CMOS operational amplifier
■Note
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1) Common mode input voltage range
ELM832xC common mode input voltage range is fixed under the condition of CMRR≥50dB; ELM832xC
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.
2) Operation from single power source
ELM832xC is designed to be most suitable for single power source, ELM832xC is able to share power
supply with logic circuit one. Meanwhile, ELM832xC can also operate from double power sources.To
protect power supplies of ELM832xC 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
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, ELM832xC is able to drive capacitive load of 100pF directly without
oscillation.
a) fig-1
b) fig-2
10 - 4
Rev.1.1