SGM8053_15 Datasheet, PDF (11/20 Pages) SG Micro Corp – CMOS Operational Amplifiers

SGM8051/2/3/4/5
250MHz, Rail-to-Rail Output
CMOS Operational Amplifiers
TYPICAL APPLICATION CIRCUITS
Differential Amplifier
The circuit shown in Figure 3 performs the difference function.
If the resistors ratios are equal (R4/R3 = R2/R1), then
V_OUT = (Vp - Vn) × R₂/R₁ + V_REF.
R2
Driving Video
The SGM805x can be used in video applications like in Figure 5.
VIN
75Ω
SGM8051
R1
Vn
Vp
R3
SGM8051
R4
VREF
VOUT
RF
RG
75Ω
CABLE
75Ω
VOUT
G = 1 + RF / RG
Figure 5. Typical Video Driving
Figure 3. Differential Amplifier
Low Pass Active Filter
The low pass filter shown in Figure 4 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.
C
R2
R1
VIN
SGM8051
VOUT
R3 = R1//R2
Figure 4. Low Pass Active Filter
SG Micro Corp
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