NJM2590/97
455kHz INPUT FM IF DEMODULATOR
GENERAL DESCRIPTION
The
NJM2590 and NJM2597
are low current FM IF demodulator
ICs with 455kHz IF input, which operate from 1.6V supply.
The
NJM2590/97
contain the minimum functions required to
FM IF demodulator, that is, IF amplifier, quadrature detector,
LPF amplifier, FSK comparator, RSSI, and RSSI comparator.
It offers unmatched design flexibility.
NJM2590V/97V
PACKAGE OUTLINE
FEATURES
Low Operating Voltage
1.6V to 5.5V
Low Operating Current
550uA at V
+
=1.8V
IF Input Frequency
455kHz (standard)
RSSI Comparator
The Range of Linear Area on RSSI Output versus IF Input Characteristics
NJN2590
IF Input level=25 to 60 dBuVEMF (reference value)
NJM2597
IF Input level=35 to 85 dBuVEMF (reference value)
Bipolar Technology
Package Outline
SSOP14
BLOCK DIAGRAM
V
+
CARRIER SENSE RSSI
SENSE LEVEL OUT
13
12
11
FSK CHARGE
OUT
10
9
LPF
OUT
8
14
RSSI
COMP
RSSI
IF AMP
FSK
COMP
CHARGE
QUAD DET
LPF
1
IF IN
2
GND
3
DEC
4
FSK
REF
5
QUAD
IN
6
AF
OUT
7
LPF
IN
Ver.2004-08-25
-1-