CS3011
CS3012
3.4
Applications
Figure 14 on page 10 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.
The CS3011 and CS3012 amplifiers are optimum
for applications that require high gain and low drift.
Figure 13 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.
A similar circuit operating from +3 V can be
constructed using the CS5540/CS5541 A/D con-
verters.
CS3001
CS3011
Dexter Research
ST60
Thermopile 1M
R2
64.9k
R1
C1
100
0.015µ F
Thermopile Amplifier with a Gain of 650 V/V
Figure 13. Thermopile Amplifier with a Gain of 650 V/V
+ 5
V
+ 5 V
+ 5
V
V A
µ
0 .1
F
V +
V R E F
A IN +
C S
x 7 6 8
µ
Ω
1 00
+
-
S D O
S C L K
Ω
Ω
Ω
µ
F
1 4 0
k
k
0 .2 2
C S 5 51 0 /1 2
Ω
3 5 0
1
m V /V
+
-
µ
3 6 5
0 .0 4 7
F
C o u n te r/T im e r
µ
0 .2 2
F
Ω
1 4 0
-
A IN 1
V -
+
1 0 0
S C L K
= 1 0 k H z to 1 0 0
(3 2 .7 6 8
S C L K = 1 0 k H z to 10 0 k H z
(3 2 .7 6 8 n o m in a l)
Figure 14. Load Cell Bridge Amplifier and A/D Converter
10
CIRRUS [ CIRRUS LOGIC ]
