AD8028 Analog Devices, AD8028 Datasheet - Page 22

• Manufacturer Part Number: AD8028
• Description: Low Distortion, High Speed Rail-to-Rail Input/Output Amplifier
• Manufacturer: Analog Devices

Specifications of AD8028

• -3db Bandwidth: 190MHz
• Slew Rate: 100V/µs
• Vos: 200µV
• Ib: 4µA
• # Opamps Per Pkg: 2
• Input Noise (nv/rthz): 4.3nV/rtHz
• Vcc-vee: 2.7V to 12V
• Isy Per Amplifier: 8.5mA
• Packages: SOIC,SOP

AD8027/AD8028
BAND-PASS FILTER
In communication systems, active filters are used extensively in
signal processing. The AD8027/AD8028 are excellent choices
for active filter applications. In realizing this filter, it is impor-
tant that the amplifier have a large signal bandwidth of at least
10× the center frequency, f
in the amplifier, causing instability and oscillations.
In Figure 62, the AD8027/AD8028 part is configured as a
1 MHz band-pass filter. The target specifications are f
and a −3 dB pass band of 500 kHz. To start the design, select f
Q, C1, and R4. Then use the following equations to calculate the
remaining variables:
k = 2πf
C2 = 0.5C1
R1 = 2/k, R2 = 2/(3k), R3 = 4/k
H = 1/3(6.5 – 1/Q)
R5 = R4/(H – 1)
V
Q
IN
=
316 Ω
Band
R1
O
C1
105 Ω
f
R2
O
Pass
Figure 62. Band-Pass Filter Schematic
(MHz)
1000pF
500pF
C1
(MHz)
C2
634 Ω
O
. Otherwise, a phase shift can occur
R3
523 Ω
R5
AD8027/
+
AD8028
–
523 Ω
+5
–5
R4
0.1 μ F
0.1 μ F
C3
C4
SELECT
O
03327-A-061
= 1 MHz
V
OUT
Rev. C | Page 22 of 24
O
,
The test data shown in Figure 63 indicates that this design
yields a filter response with a center frequency of f
and a bandwidth of 450 kHz.
DESIGN TOOLS AND TECHNICAL SUPPORT
Analog Devices, Inc. (ADI) is committed to simplifying the
design process by providing technical support and online
design tools. ADI offers technical support via free evaluation
boards, sample ICs, interactive evaluation tools, data sheets,
spice models, application notes, and phone and email support
available at www. analog.com.
0.1
CH1 S21 LOG
Figure 63. Band-Pass Filter Response
FREQUENCY – MHz
5dB/REF 6.342dB
1
1
1:6.3348dB 1.00 000MHz
03327-A-062
O
= 1 MHz,
10