NJM2232A
FM IF WITH LOG AMPLIFIER
■
GENERAL DESCRIPTION
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
Dynamic Range
Temperature
●
Low power dissipation (V
CC
=6V)
●
Operating voltage
●
Package Outline
●
Bipolar Technology
■
PACKAGE OUTLINE
NJM2232AM
±1dB
90dB
±2dB
5.2mA typ.
5 to 9V
DMP24
■
RECOMMENDED OPERATIONAL CONDITION
5.0 to 9.0V
●
Operating Voltage
V
+
■
APPLICATION
●
Automobile telephone
●
Codeless telephone
●
MCA
●
Celler Radio
●
Business Wireless apparatus
●
Various measuring units
■
BLOCK DIAGRAM
NJM2232AM
Ver.2003-12-09
-1-
NJM2232A
■
TERMINAL EXPLANATION
PIN
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
SYMBOL
V
CC
IF IN
GND
EXT. C1
EXT. C2
DEC 1
FILT IN
DEC 2
EXT.C3
AGND
IF OUT
AV
CC
RSSI
CV
CC
QUAD IN
CGND
AF OUT
DEC 3
BGND
MIX IN
OSC 2
OSC 1
BV
CC
MiX OUT
Function
Supply Voltage Input of IF-AMP 1, RSSI and Reference
IF-AMP1 ( Limitter Amp.) Signal Input
Ground of IF-AMP 1, RSSI and Reference
Capacitor Connection Terminal 1 (Limitter Amp. AC Decoupling)
Capacitor Connection Terminal 2 (Limitter Amp. AC Decoupling)
Reference Decoupling Capacitor 1
Filter Input between IF-AMP 1 and IF-AMP 2
Reference Decoupling Capacitor 2
Capacitor Connection Terminal 3 (Limitter Amp. AC Decoupling)
Ground of IF-AMP 2, and RSSI
IF-AMP 2 (Limitter Amp.) Signal Output
Supply Voltage Input of IF-AMP 2 and RSSI
RSSI Input
FM-DISCRI Supply Voltage Input
Quadrature Detector Input
FM-DISCRI Ground
Audio Signal Output
Reference Decoupling Capacitor 3
Mixer Ground
Mixer Signal Input
Crystal Oscillator Terminal 2
Crystal Oscillator Terminal 1
Mixer Supply Voltage Input
Mixer Signal Output
■
ABSOLUTE MAXIMUM RATINGS
PARAMETER
Supply Voltage
Power Dissipation
Operating Temperature Range
Storage Temperature Range
SYMBOL
V
+
(T
a
=25°C)
RATINGS
12
700
-20 to +75
-40 to +125
UNIT
V
mW
°C
°C
P
D
Topr
Tstg
■
ELECTRICAL CHARACTERISTICS
PARAMETER
SYMBOL
TEST CONDITION
MIN.
TYP.
(V
+
=6V, T
a
=25°C±2°C)
MAX.
UNIT
Operating Current
I
CC
11, 21, 22pin, no loading
-
5.2
8.5
mA
Mixer Voltage Gain
G
MIX
f
IN
=90MHz, -40dBm
18
20
22
dB
RSSI Output Voltage (1)
V
L1
f
IN
=455kHz, -90dBm
0.135
-
0.405
V
RSSI Output Voltage (2)
V
L2
f
IN
=455kHz, -80dBm
0.41
-
0.71
V
RSSI Output Voltage (3)
V
L3
f
IN
=455kHz, 0dBm
2.56
-
2.94
V
RSSI Linearity
V
LIN
(Note 1)
-1
0
1
dB
RSSI Dynamic Range
DR
(Note 1)
90
-
-
dB
IF Output Voltage
V
IF
f
IN
=455kHz, -50dBm
1.2
1.4
1.6
V
Audio Output Voltage
V
OUT
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) f
IN
=455kHz, -20dBm, f
MOD
=1kHz, f
DEV
=3kHz
(Note 3) f
IN
=455kHz, -20dBm, f
MOD
=1kHz, AM 30%MOD
-2-
Ver.2003-12-09
NJM2232A
■
TEST CIRCUIT
Ver.2003-12-09
-3-
NJM2232A
■
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.
‹Oscillator›
(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.
NJM2232A
‹Supply Voltage›
(5) Limitter Amp. Input
Limitter amp. impedance is designed to be 18kΩ (standard). Be sure
to input after DC cutting.
‹Limitter Amp. Input›
(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.
‹Decoupling Capacitor›
-4-
Ver.2003-12-09
NJM2232A
(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.
‹Inter Section Filter›
(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).
‹Limitter Amp. Output›
(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.
‹Phase Shifter›
(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.
‹RSSI Output›
Ver.2003-12-09
-5-
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