Datasheet

LTC2057/LTC2057HV
23
2057f
For more information www.linear.com/LTC2057
Typical applicaTions
DC Stabilized, Ultralow Noise Composite Amplifier
Low-Side Current Sense Amplifier
2057 TA02
R
G
20Ω
V
IN
V
OUT
20V
20V
20V
20k
R
F
2k
47nF
1k
8
–20V
–20V
LTC2057HV
+
–
LT1037
+
–
1MΩ
A
V
=
R
F
R
G
+ 1 = 101
COMPOSITE AMPLIFIER COMBINES THE EXCELLENT BROADBAND NOISE
PERFORMANCE OF THE LT1037 WITH THE ZERO-DRIFT PROPERTIES OF
THE LTC2057. THE RESULTING CIRCUIT HAS MICROVOLT ACCURACY,
SUPPRESSED 1/f NOISE, AND LOW BROADBAND NOISE.
2057 TA03
+
–
10Ω
1k
28V
1N4148
OR EQUIVALENT
OPTIONAL
SHORT
V
OUT
V
OUT
= 101 • R
SENSE
• I
SENSE
LTC2057
V
SENSE
I
SENSE
10Ω
R
SENSE
+
–
FREQUENCY (Hz)
0.1 1
0
10
INPUT VOLTAGE NOISE DENSITY (nV/√Hz)
20
18
16
14
12
8
6
4
2
10 100
2057 TA02b
Low-Side Current Sense Amplifier
Transfer Function
Input Voltage Noise Spectrum
of Composite Amplifier
V
SENSE
(µV)
0
0
1.0
2.0
3.0
V
OUT
(mV)
3.5
0.5
1.5
2.5
5
10
20
15
25
30
2057 TA03b
DIODE NOT SHORTED
DIODE SHORTED
IDEAL TRANSFER
FUNCTION
AMPLIFIER OUTPUT SATURATES
WITH DIODE SHORTED