SGM8652_15 Datasheet, PDF (9/18 Pages) SG Micro Corp – CMOS Operational Amplifiers

SGM8651/2/4
SGM8653/5
50MHz, Rail-to-Rail Output
CMOS Operational Amplifiers
TYPICAL APPLICATION CIRCUITS
Differential Amplifier
The circuit shown in Figure 4 performs the difference function. If
the resistors ratios are equal (R4/R3 = R2/R1), then
V_OUT = (Vp - Vn) × R₂/R₁ + V_REF.
R2
R1
Vn
SGM8651
VOUT
Vp
R3
R4
VREF
Figure 4. Differential Amplifier
Low Pass Active Filter
The low pass filter shown in Figure 6 has a DC gain of (-R₂/R₁)
and the -3dB corner frequency is 1/2R2C. Make sure the filter
bandwidth is within the bandwidth of the amplifier. The large
values of feedback resistors can couple with parasitic
capacitance and cause undesired effects such as ringing or
oscillation in high-speed amplifiers. Keep resistor values as low
as possible and consistent with output loading consideration.
R₁
V_IN
C
R₂
SGM8651
V_OUT
Instrumentation Amplifier
The circuit in Figure 5 performs the same function as that in
Figure 4 but with the high input impedance.
SGM8651
Vn
Vp
SGM8651
R2
R1
SGM8651
VOUT
R3
R4
VREF
R₃ = R₁ // R₂
Figure 6. Low Pass Active Filter
Driving Video
The SGM865x can be used in video applications like in Figure 7.
VIN
SGM8651
RF
RG
75Ω
75Ω
CABLE
75Ω
VOUT
Figure 5. Instrumentation Amplifier
G = 1 + RF / RG
Figure 7. Typical Video Driving
SG Micro Corp
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