PRODUCT SPECIFICATION
FM20
In environments that are particularly noisy it may be neces-
sary to add a low-pass filter network to the output of the
device. As shown below, a 1µF capacitor in addition to the
output impedance of the device and a 200Ω series resistor
for a low-pass filter that will pass the slow thermal time con-
stant of the FM20, while filtering the higher frequency noise.
The response time of the FM20 can be affected by this filter
network, therefore values for CFILTER < 1500pF are recom-
mended.
0.1µF
Bypass
Cap
GND
VDD
VOUT
CFILTER
RFILTER
CL
GND
CFILTER
0.1µF
Bypass
Cap
VDD
VOUT
CL
RFILTER
Figure 3. FM20 with Filter Network for Noisy Environments or for Capacitive Loads Greater than 300pF
Table 1. Resistor/Capacitor Combinations for Filter Network
RFILTER
200Ω
470Ω
CFILTER
1µF
0.1µF
680Ω
1000Ω
10kΩ
100kΩ
0.01µF
1000pF
100pF
10pF
REV. 1.0.6 1/9/03
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