CS3001
CS3002
for amplifying small signals with large gains in ap-
plications where the output of the amplifier can be
band-limited to frequencies below 2 kHz.
3. CS3001/CS3002 OVERVIEW
The CS3001/CS3002 amplifiers are designed for
precision measurement of signals from DC to
2 kHz when operating from a supply voltage of
+2.7 V to +6.7 V ( 1.35 to 3.35 V). The ampli-
fiers are designed with a patented architecture that
utilizes multiple amplifier stages to yield very high
open loop gain at frequencies of 10 kHz and below.
The amplifiers yield low noise and low offset drift
while consuming relatively low supply current. An
increase in noise floor above 2 kHz is the result of
intermediate stages of the amplifier being operated
at very low currents. The amplifiers are intended
3.1
Open Loop Gain and Phase
Response
Figure 9 illustrates the open loop gain and phase re-
sponse of the CS3001/CS3002. The gain slope of
the amplifier is about –100 dB/decade between
500 Hz and 60 kHz and transitions to –20 dB/de-
cade between 60 kHz and its unity gain crossover
frequency at about 4.8 MHz. Phase margin at unity
gain is about 70 degrees; gain margin is about
20 dB.
100
80
-100 dB/ dec
60
40
20
-20 dB/ dec
0
-45
-90
-135
-180
-225
-270
-315
-360
10K
10M
1M
100K
Figure 9. CS3001/CS3002 Open Loop Gain and Phase Response
7
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