BU7291G Datasheet, PDF (23/27 Pages) Rohm – High Speed with Low Voltage CMOS Operational Amplifiers

BU7291G,BU7291SG,BU7255HFV,BU7255SHFV,
BU7495HFV,BU7495SHFV,BU7481G,BU7481SG,BU7485G,BU7485SG,BU5281G,BU5281SG
●Examples of circuit
○Voltage follower
Technical Note
VDD
Voltage gain is 0 [dB].
This circuit controls output voltage (Vout) equal input
voltage (Vin), and keeps Vout with stable because of
high input impedance and low output impedance.
Vout is shown next formula.
Vout=Vin
Vout
Vin
VSS
Fig.146 Voltage follower
○Inverting amplifier
Vin
R1
R2
VDD
For inverting amplifier, Vin is amplified by voltage gain
decided R1 and R2, and phase reversed voltage is
outputted. Vout is shown next formula.
Vout=-(R2/R1)・Vin
Input impedance is R1.
Vout
R1//R2
VSS
Fig.147 Inverting amplifier circuit
○Non-inverting amplifier
R1
R2
VDD
Vout
Vin
For non-inverting amplifier, Vin is amplified by voltage
gain decided R1 and R2, and phase is same with Vin.
Vout is shown next formula.
Vout=(1+R2/R1)・Vin
This circuit realizes high input impedance because
Input impedance is operational amplifier’s input
Impedance.
VSS
Fig.148 Non-inverting amplifier circuit
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23/26
2010.12 - Rev.A