NJM2593

-1-

Ver.2004-08-25

50MHz INPUT MIXER AND 450kHz FM IF DEMODULATOR IC

GENERAL DESCRIPTION

PACKAGE OUTLINE

The NJM2593

is a wide-operating voltage, low-current

FM IF demodulator IC with 450kHz(standard) IF frequency.

It includes an oscillator, mixer, limiting amplifier, quadrature

detector, active filter, and FSK comparator.

The NJM2593

also has a RSSI circuit and RSSI comparator

for carrier sense.

NJM2593V

FEATURES

Wide Operating Voltage

1.8V to 9.0V

Low Operating Current

Maximum Mixer Input Signal

Frequency

50MHz (reference value)

Mixer Input Resistance

4.5kΩ (reference value)

IF Frequency

450kHz (standard)

Conventional Quadrature Detector

External Phase-shifting Capacitor

External Discriminator or LC Resonant Circuit

RSSI Comparator with Open-Collector Output

Quick Charge/Discharge Circuit for FSK Reference Voltage

Bipolar Technology

Package Outline

SSOP20

BLOCK DIAGRAM

20

19

18

17

16

15

14

13

12

11

BUFFER

OSC

MIXER

RSSI COMP

IF AMP

FILTER AMP

QUAD

DET

FSK COMP

CHARGE

1

2

3

4

5

6

7

8

9

10

OSC

(B)

OSC

(E)

MIX

OUT

V+

IF

IN

DEC

IF

OUT

QUAD

IN

AF

OUT

LPF

OUT

CHARGE

SW

FSK

OUT

FSK

VREF2

CARRIER

SENSE

RSSI

OUT

SENSE

LEVEL

GND

MIX

IN

LPF

IN

RSSI

FSK

VREF1

+

-

+

-

+

-

-

+