ADA4075-2 Analog Devices, ADA4075-2 Datasheet - Page 19

• Manufacturer Part Number: ADA4075-2
• Description: Ultralow Noise Amplifier at Lower Power
• Manufacturer: Analog Devices

Specifications of ADA4075-2

• -3db Bandwidth: 6.5MHz
• Slew Rate: 12V/µs
• Vos: 300µV
• Ib: 30nA
• # Opamps Per Pkg: 2
• Input Noise (nv/rthz): 2.8nV/rtHz
• Vcc-vee: 24V to 36V
• Isy Per Amplifier: 1.8mA
• Packages: CSP,SOIC

Data Sheet
BALANCED LINE RECEIVER
Figure 68 depicts a unity-gain balanced line receiver capable of
a high degree of hum rejection. The CMRR is approximately
given by
Therefore, R1 to R4 should be close tolerance components to
obtain the best possible CMRR without adjustment. The presence
of A2 ensures that the impedances are symmetric at the two inputs
(unlike many other designs), and, as a bonus, A2 also provides
a complementary output. A3 raises the common-mode input
impedance from approximately 7.5 kΩ to approximately 70 kΩ,
reducing the degradation of CMRR due to mismatches in source
impedance.
20
log
10




R1
R2


R4
R3




(NON-POLAR)
*A3 REDUCES THE DEGRADATION OF CMRR
(SEE THE BALANCED LINE RECEIVER SECTION FOR MORE DETAILS).
IN+
IN–
5.6kΩ
22µF
R7
C1
R8
5.6kΩ
11kΩ
R9
5kΩ
A3*
R2
5kΩ
R1
Figure 68. Balanced Line Receiver
ADA4075-2
Rev. B | Page 19 of 24
11kΩ
R10
50pF
10kΩ
C2
R3
1/2
A1
10kΩ
5kΩ
R5
R4
Note that A3 is not in the signal path, and almost any op amp
works well here. Although it may seem as though the inverting
output should be noisier than the noninverting one, they are in
fact symmetric at about −111 dBV (20 kHz bandwidth).
Sometimes an overall gain of ½ is desired to provide an extra
6 dB of differential input headroom. This can be attained by
reducing R3 and R4 to 5 kΩ and increasing R9 to 22 kΩ.
ADA4075-2
50pF
5kΩ
C3
R6
1/2
A2
OUT+
OUT–
ADA4075-2