LTC2057/LTC2057HV
Typical applicaTions
Paralleling Choppers to Improve Noise
+
R5
LTC2057
R2
–
R1
+
–
R5
LTC2057
R2
R2
R1
R4
R3
+1
•
+1
A
=
V
V
+
–
IN
LTC2057
R4
V
OUT
R1
+
–
R5
LTC2057
R2
R3
R1
+
–
R5
LTC2057
R2
2057 TA04
R1
200nV
√N
11nV/√Hz
√N
P-P
DC TO 10Hz NOISE =
, e
n
=
, i = √N • 170fA/√Hz, I < N • 200pA (MAX)
n B
WHERE N IS THE NUMBER OF PARALLELED INPUT AMPLIFIERS.
FOR N = 4, DC TO 10Hz NOISE = 100nV , e = 5.5nV/√Hz, i = 340fA/√Hz, I < 800pA (MAX).
P-P
n
n
B
R
SHOULD BE A FEW HUNDRED OHMS TO ISOLATE AMPLIFIER OUTPUTS WITHOUT
5
CONTRIBUTING SIGNIFICANTLY TO NOISE OR I -INDUCED ERROR.
B
R2
R1
+1 >> √N FOR OUTPUT AMPLIFIER NOISE TO BE INSIGNIFICANT.
2057f
24
For more information www.linear.com/LTC2057
LINEAR_DIMENSIONS [ Linear Dimensions ]
