NJM2550 JRC, NJM2550 Datasheet - Page 7

• Manufacturer Part Number: NJM2550
• Description: FM IF Demodulator IC / SSOP16
• Manufacturer: JRC

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Ver.2006-02-24
Pin No.
12
13
14
15
COMP OUT
COMP REF
COMP IN
CHARGE
SYMBOL
SWITCH
12
13
14
15
EQUIVARENT CIRCUIT
20uA
300k
20uA
20uA
10uA
GND
V+
GND
GND
V+
GND
VOLTAGE
--
--
--
--
Comparator Input
This pin is an input of the wave
shaping comparator.
Comparator Reference Input
This pin is an input of reference
voltage for the wave shaping
comparator. A capacitor is
connected to create an average
DC Level of FM demodulated
signal. The value of this capacitor
is dependant on the speed of data
signal. A quick charge /discharge
circuit offers the voltage of pin13
comes the average DC Level of
FM demodulated signal very
quickly.
Comparator Output
An open-collector output.
The comparator is non-reverse
type. When the frequency of IF
input signal is fif + , the output is
“Low”. When the frequency of IF
input signal is fif - , the output is
“High”.
Instead of V+, another power
source can be used within the limit
of the rated supply voltage.
Quick
Circuit ON / OFF Control
The quick charge/discharge circuit
is in the active stage when pin15
is pulled up to V+. This circuit is in
the stand-by stage when pin15 is
pulled down to GND. Instead of
V+, another power source can be
used within the limit of the rated
power supply voltage.
Charge
FUNCTION
NJM2550
/
Discharge
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