NJM2232A
-1-
Ver.2003-12-09
FM IF WITH LOG AMPLIFIER
■ GENERAL DESCRIPTION ■ PACKAGE OUTLINE
The NJM2232A is high precision FM IF IC with log amplifier, designed to be used
for handy type wireless apparatus.
The NJM2232A includes in one chip of IC, at each block, the mixer, local oscillator,
limitter amplifier, log amplifier, FM detector, and so on, with which set up the IF block
of handy type wireless apparatus that requires high precision electronic detection.
■ FEATURES
● RSSI features are excellent
Linearity ±1dB
Dynamic Range 90dB
Temperature ±2dB
● Low power dissipation (VCC=6V) 5.2mA typ.
● Operating voltage 5 to 9V
● Package Outline DMP24
● Bipolar Technology
■ RECOMMENDED OPERATIONAL CONDITION
● Operating Voltage V+ 5.0 to 9.0V
■ APPLICATION
● Automobile telephone
● Codeless telephone
● MCA
● Celler Radio
● Business Wireless apparatus
● Various measuring units
■ BLOCK DIAGRAM
NJM2232AM
NJM2232AM
NJM2232A
- 2 - Ver.2003-12-09
■ TERMINAL EXPLANATION
PIN SYMBOL Function
1 VCC Supply Voltage Input of IF-AMP 1, RSSI and Reference
2 IF IN IF-AMP1 ( Limitter Amp.) Signal Input
3 GND Ground of IF-AMP 1, RSSI and Reference
4 EXT. C1 Capacitor Connection Terminal 1 (Limitter Amp. AC Decoupling)
5 EXT. C2 Capacitor Connection Terminal 2 (Limitter Amp. AC Decoupling)
6 DEC 1 Reference Decoupling Capacitor 1
7 FILT IN Filter Input between IF-AMP 1 and IF-AMP 2
8 DEC 2 Reference Decoupling Capacitor 2
9 EXT.C3 Capacitor Connection Terminal 3 (Limitter Amp. AC Decoupling)
10 AGND Ground of IF-AMP 2, and RSSI
11 IF OUT IF-AMP 2 (Limitter Amp.) Signal Output
12 AVCC Supply Voltage Input of IF-AMP 2 and RSSI
13 RSSI RSSI Input
14 CVCC FM-DISCRI Supply Voltage Input
15 QUAD IN Quadrature Detector Input
16 CGND FM-DISCRI Ground
17 AF OUT Audio Signal Output
18 DEC 3 Reference Decoupling Capacitor 3
19 BGND Mixer Ground
20 MIX IN Mixer Signal Input
21 OSC 2 Crystal Oscillator Terminal 2
22 OSC 1 Crystal Oscillator Terminal 1
23 BVCC Mixer Supply Voltage Input
24 MiX OUT Mixer Signal Output
■ ABSOLUTE MAXIMUM RATINGS (Ta=25°C)
PARAMETER SYMBOL RATINGS UNIT
Supply Voltage V+ 12 V
Power Dissipation PD 700 mW
Operating Temperature Range Topr -20 to +75 °C
Storage Temperature Range Tstg -40 to +125 °C
■ ELECTRICAL CHARACTERISTICS (V+=6V, Ta=25°C±2°C)
PARAMETER SYMBOL TEST CONDITION MIN. TYP. MAX. UNIT
Operating Current ICC 11, 21, 22pin, no loading - 5.2 8.5 mA
Mixer Voltage Gain GMIX f
IN=90MHz, -40dBm 18 20 22 dB
RSSI Output Voltage (1) VL1 f
IN=455kHz, -90dBm 0.135 - 0.405 V
RSSI Output Voltage (2) VL2 f
IN=455kHz, -80dBm 0.41 - 0.71 V
RSSI Output Voltage (3) VL3 f
IN=455kHz, 0dBm 2.56 - 2.94 V
RSSI Linearity VLIN (Note 1) -1 0 1 dB
RSSI Dynamic Range DR (Note 1) 90 - - dB
IF Output Voltage VIF f
IN=455kHz, -50dBm 1.2 1.4 1.6 V
Audio Output Voltage VOUT Standard Modulation Signal (Note 2) 150 200 250 mV
Total Harmonic Distortion THD Standard Modulation Signal (Note 2) - - 1 %
S / N Ratio S / N Standard Modulation Signal (Note 2) 40 - - dB
AMRR AMR Standard Modulation Signal (Note 3) 30 - - dB
(Note 1) RSSI Linearity has 10 measuring points (-90, -80 to 0dBm) from where getting the ideal linearity by way of mini square method, and
that each 10 measured spots should stay on within the range of ±1dB that can be obtained during the process of the measurement.
Also in the process of the measurement, RSSI dynamic range 90dB can be obtained at the same time.
(Note 2) fIN=455kHz, -20dBm, fMOD=1kHz, fDEV=3kHz
(Note 3) fIN=455kHz, -20dBm, fMOD=1kHz, AM 30%MOD
NJM2232A
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Ver.2003-12-09
■ TEST CIRCUIT
NJM2232A
- 4 - Ver.2003-12-09
■ TERMINAL EXPLANATION
(1) Supply Voltage
The supply voltage is to be delivered at each block, such as limitter
Amplifier block ((1), (12) pin), Mixer bolck (23) pin, FM Discrimination
block (14) pin and so on. When applying the voltage, proceed it
supplying from the latter bolck to front in order of the block structure.
When the mixer block and FM block are not required the IC is not
operation, no functioning as long as the power supply is off.
(2) Mixer Input
Mixer input impedance (20) pin is designed to be set at 1.5kΩ
(standard) on voltage. It is advisable to input after DC cutting for
desired matched circuit.
(3) Oscillator
As far as the local oscillator ionput goes, there are 2 methods as
shown below.
1. Input after setting the crystal oscillating circuit, on (21), (22) pins.
2. Connect (21) pin directly on supply voltage, and then input the
external local oscillator output directly to pin 22.
(4) Filter (to be used between Mixer and Limitter Amp.)
Mixer output impedance (24) pin is 2kΩ (standard), Limitter Amp.
Impedance (2) pin is 18kΩ (standard) are desired.
Input harmonizing to the filter to be used for adequate matched
circuit.
(5) Limitter Amp. Input
Limitter amp. impedance is designed to be 18kΩ (standard). Be sure
to input after DC cutting.
(6) Decoupling Capacitance
(4), (5), (9) pins capacitor are AC decoupling capacitor, Which are set
as a part of amplifier feed back circuit of Limmitter amp. block. Please
apply about 0.1µF capacitance.
(7) Reference Capacitor
(6), (8), (18) pins capacitor are AC decoupling capacitor which are to
be connected to the internal reference. Please apply 0.1µF
capacitance.
NJM2232A
‹Supply Voltage›
‹Oscillator›
‹Limitter Amp. Input›
‹Decoupling Capacitor›
NJM2232A
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Ver.2003-12-09
(8) Limitter Amp. Inter Section Filter
The limitter amp, the inter section filter is composed of the resonator
applied with the tuning coil as in the drawing.
Upon designing the RSSI linearity, it is advisable to apply the
resonator coil with no loading Q=55, L=680µH condition, and so
proceed DC cutting before the coil.
(9) Limitter Amplifier
As shown in the drawing, the limitter amp. is the open emitter, and the
limitter amp. output can be obtained by putting adequate resistor to
pin (11).
(10) Quadrature Detecting phase Shifter
In order to detect quadrature, input the signal that has shifted the
phase for 90 degree from pin (15) to RLC paralleled resonator.
The resistor value should be decided to obtain the desired audio
output.
(11) RSSI detecting current shall be shifted from current into voltage by
the internal resistor 32kΩ, And at the same time, please put the
external capacitor value to be able to stay constantly for the desired
time.
‹Inter Section Filter›
‹Limitter Amp. Output›
‹Phase Shifter›
‹RSSI Output›
NJM2232A
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■ TYPICAL APPLICATION
NJM2232A
-7-
Ver.2003-12-09
■ TYPICAL CHARACTERISTICS
Mixer Voltage Gain vs. Frequency Mixer Voltage Gain vs. Local Input Level
RSSI Characteristics vs. Mixer Input RSSI Output Voltage vs. Temperature
[CAUTION]
The specifications on this databook are only
given for information , without any guarantee
as regards either mistakes or omissions. The
application circuits in this databook are
described only to show representative usages
of the product and not intended for the
guarantee or permission of any right including
the industrial rights.
