CS3011_07 Datasheet, PDF (14/18 Pages) Cirrus Logic – Precision Low-voltage Amplifier; DC to 1 kHz

CS3011
CS3012
3.4 Applications
The CS3011 and CS3012 amplifiers are optimum
for applications that require high gain and low drift.
Figure 18 illustrates a thermopile amplifier with a
gain of 650 V/V. The thermopile outputs only a few
millivolts when subjected to infrared radiation. The
amplifier is compensated and bandlimited by C1 in
combination with R2.
Figure 19 on page 14 illustrates a load cell bridge
amplifier with a gain of 768 V/V. The load cell is ex-
cited with +5 V and has a 1 mV/V sensitivity. Its full
scale output signal is amplified to produce a fully
differential ± 3.8 V into the CS5510/12 A/D convert-
er. This circuit operates from +5 V.
A similar circuit operating from +3 V can be
constructed using the CS5540/CS5541 A/D con-
verters.
Dexter Research
Thermopile ST60
CS3011
R2
64.9k
+5 V
VA
1 m V /V
-
350 Ω
R1
C1
100
0.015µF
Figure 18. Thermopile Amplifier with a Gain of 650 V/V
+5 V
0.1 µ F
V+
x768
+
-
1 4 0 kΩ
100 Ω
0.2 2 µ F
VREF
CS
A IN +
SDO
SCLK
C S 551 0/1 2
+
365 Ω
0.0 47 µ F
+5 V
µ
1 4 0 kΩ
-
+
0.2 2 µ F
100 Ω
A IN 1
V-
C o u n te r/T im e r
S C LK = 1 0 kH z to 10 0
(32 .76 8
S C L K = 1 0 k H)z t o 1 0 0 k H z
(3 2 .7 6 8 n o m in a l)
Figure 19. Load Cell Bridge Amplifier and A/D Converter
14
DS597F5