SGM8051_17 Datasheet, PDF (11/20 Pages) SG Micro Corp – CMOS Operational Amplifiers

SGM8051/2/3/4/5
TYPICAL APPLICATION CIRCUITS
Differential Amplifier
The circuit shown in Figure 3 performs the difference
function. If the resistor ratios are equal (R₄/R₃ = R₂/R₁),
then V_OUT = (V_P - V_N) × R₂/R₁ + V_REF.
R2
R1
VN
SGM8051
VOUT
VP
R3
R4
VREF
Figure 3. Differential Amplifier
Active Low-Pass Filter
The low-pass filter shown in Figure 4 has a DC gain of
(-R₂/R₁) and the -3dB corner frequency is 1/2πR₂C.
Make sure the filter bandwidth is within the bandwidth
of the amplifier. Feedback resistors with large values
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
250MHz, Rail-to-Rail Output,
CMOS Operational Amplifiers
Driving Video
The SGM8051 series can be used in video applications
as shown in Figure 5.
VIN
SGM8051
RF
RG
75Ω
75Ω
CABLE
VOUT
75Ω
G = 1 + RF/RG
Figure 5. Typical Video Driving
R3 = R1 // R2
Figure 4. Active Low-Pass Filter
SG Micro Corp
www.sg-micro.com
JUNE 2017
11