NJM2593
50MHz INPUT MIXER AND 450kHz FM IF DEMODULATOR IC
PACKAGE OUTLINE
GENERAL DESCRIPTION
The NJM2593 is an FM IF demodulator IC with 450kHz (standard)
IF frequency, which operates from 1.8V to 9V supply, low-current.
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
1.2mA type. at V+ =2.0V, external local oscillator input
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
MIX
IN
SENSE RSSI CARRIER FSK CHARGE LPF
SW
OUT
GND LEVEL OUT SENSE OUT
20
19
18
17
16
15
14
12
11
+
-
RSSI COMP FSK COMP
BUFFER
AF
OUT
13
+
+
-
MIXER
LPF
IN
RSSI
FILTER AMP
CHARGE
QUAD
DET
+
-
OSC
IF AMP
Ver.2018-03-09
1
2
3
4
5
6
OSC
(B)
OSC
(E)
MIX
OUT
V+
IF
IN
DEC
7
8
FSK
FSK
VREF1 VREF2
9
10
IF
OUT
QUAD
IN
-1-
NJM2593
ABSOLUTE MAXIMUM RATINGS
PARAMETER
(Ta=25°C)
SYMBOL
RATINGS
UNIT
Supply Voltage
V+
10.0
V
Power Dissipation
Pd
300
mW
Operating Temperature
Topr
- 40 to +85
°C
Storage Temperature
Tstg
- 40 to +125
°C
RECOMMENDED OPERATING CONDITION
PARAMETER
Supply Voltage
SYMBOL
TEST CONDITIONS
V+
(Ta=25°C)
MIN.
TYP.
MAX.
UNIT
1.8
2.0
9.0
V
ELECTRICAL CHARACTERISTICS
(Ta=25°C, V+=2.0V, fmix=21.7MHz, flo=21.25MHz, fif=450kHz, fmod=600Hz, fdev=±2kHz, unless otherwise noted)
PARAMETER
SYMBOL
TEST CONDITIONS
MIN.
TYP.
MAX.
UNIT
-
1.2
1.5
mA
17
20
23
dB
IP3
-
95
-
dBuV
Mixer Input Resistance
R in M
-
4.5
-
kΩ
Mixer Input Capacitance
C in M
-
2.0
-
pF
Mixer Output Resistance
R oM
-
1.8
-
kΩ
Signal to Noise Ratio 1
S/N1
-
60
-
dB
Signal to Noise Ratio 2
S/N2
40
60
70
dB
Signal to Noise Ratio 3
S/N3
20
30
40
dB
-3dB Limiting Sensitivity
Vin(lim)
IF input
-
22
-
dBuVEMF
IF input, AM=30%
VinIF=60dBuVEMF
-
50
-
dB
-
1.8
-
kΩ
0.35
0.5
0.65
V
Current Consumption
Iccq
No signal
Mixer Conversion Gain
Gmix
VinMIX=60dBuVEMF,
Measured at Pin3, without IF
filter, with 1.8kΩ+0.1uF
Mixer 3 rd Order Intercept
AM Rejection Ratio
AMR
IF Amplifier Input Resistance
RinIF
RSSI Output Voltage
Vrssi
-2-
Mixer input
VinMIX=60dBuVEMF
IF input
VinIF=60dBuVEMF
IF input
VinIF=25dBuVEMF
IF input
VinIF=40dBuVEMF
Ver.2018-03-09
NJM2593
PARAMETER
SYMBOL
Demodulated Output Level
V od
Duty Ratio of Wave Shaped Output
DR
Quick Charge/Discharge Current
Ich
High Level Leak Current of
CARRIER SENSE Terminal
Low Level Voltage of
CARRIER SENSE Terminal
Bias Current of
SENSE LEVEL Terminal
High Level Leak Current of
FSK OUT Terminal
Low Level Voltage of
FSK OUT Terminal
Ver.2018-03-09
TEST CONDITIONS
IF input
VinIF =60dBuVEMF
IF Input
VinIF=60dBuVEMF
FSK REF=GND
LPFOUT=0.4V
MIN.
TYP.
MAX.
UNIT
70
80
90
mVrms
40
50
60
%
35
65
110
uA
IcryH
VCARRIER SENSE=V+
-
0.0
-
uA
VcryL
ICARRIER SENSE=100uA
-
0.1
0.4
V
I l e ve l
VCARRIER SENSE=0.8V
-
0.0
-
uA
IfskH
VFSK OUT=V+
-
0.0
-
uA
VfskL
IFSK OUT=100uA
-
0.1
0.4
V
-3-
NJM2593
TEST CIRCUIT
This test circuit allows the measurement of all parameters described in “ELECTRICAL CHARACTERISTICS”. This
test circuit includes some electrical switches that should be in the suitable position for the measurement of each
parameter.
Test Circuit 1 (except for Gmix)
SENSE RSSI CARRIER FSK
LEVEL OUT SENSE OUT
AF
OUT
CHARGE
SWITCH
V+
1000p
21.7MHz
100k
1000p
RF IN
0.01u
Lo
Hi
100k
68k
68k
560p
68k
3300p
51
20
19
18
17
16
15
14
12
+
+
-
MIXER
13
+
-
RSSI COMP FSK COMP
BUFFER
11
FILTER AMP
RSSI
CHARGE
QUAD
DET
+
-
OSC
IF AMP
1
1000p
2
3
4
OPEN
6
7
8
9
10
+
V
1000p
C1
0.1u
0.1u
10u
LO IN
21.25MHz
5
+
10u
V
51
B
IF IN
A
10u
450kHz
IF SW
IF FILTER
CD
R1
51
Test Circuit 2 (for Gmix)
SENSE RSSI CARRIER FSK
LEVEL OUT SENSE OUT
AF
OUT
CHARGE
SWITCH
V+
1000p
21.7MHz
100k
1000p
RF IN
0.01u
Lo
Hi
100k
68k
68k
560p
68k
3300p
51
20
19
18
17
16
15
14
+
+
-
MIXER
13
11
+
-
RSSI COMP FSK COMP
BUFFER
12
RSSI
FILTER AMP
CHARGE
QUAD
DET
+
-
OSC
IF AMP
1
1000p
2
3
0.1u
4
MIX OUT
7
0.1u
10
B
A
IF SW
+
10u
1.8k
IF FILTER
9
C1
0.1u
51
-4-
8
+
10u
51
6
V
1000p
LO IN
21.25MHz
5
V
CD
R1
IF IN
450kHz
10u
Ver.2018-03-09
NJM2593
External components
CD
: Ceramic Discriminator, 450kHz
IF FILTER : Ceramic Filter, 450kHz
Measurement condition
“Condition1” is the condition for the case of IF input :
IF SW
: in the A position.
IF IN input signal : input frequency(fif) = 450kHz, input level(VinIF)= 60dBuVEMF,
modulation frequency(fmod)=600Hz, deviation fdev=±2kHz
“Condition 2” is the condition for the case of Mixer Input :
IF SW
: in the B position
MIX IN input signal: input frequency(fmix)=21.7MHz, input level(VinMIX)=60dBuVEMF,
modulation frequency(fmod)=600Hz, deviation fdev=±2kHz
OSC(E)input signal: input frequency(fosc)=21.25MHz, input level(VinOSC)=105dBuVEMF
Ver.2018-03-09
-5-
NJM2593
TERMINAL FUNCTION (Ta=25°C, V+=2.0V)
Pin No.
1
SYMBOL
EQUIVARENT CIRCUIT
V+
OSC (B)
VOLTAGE
FUNCTION
1.98V
Base / Emitter Terminal
Colpitts - type oscillator is formed
with an external oscillator element
of crystal unit or SAW resonator.
Output of an external oscillator
circuit can also input to pin1 or
pin2.
20k
1
2
2
80u
OSC (E)
1.28V
Mixer Output
An external 450kHz ceramic filter is
connected. The typical output
impedance is 2kΩ.
V+
100k
3
MIX OUT
1.18V
20p
1.1k
3
100u
4
V+
-
-
V+
5
IF IN
1.96V
50k
900
900
5
6
6
DEC
1.96V
V+
7
-6-
FSK VREF1
7
0.46V
Supply Voltage
IF Limiter Amplifier Input
This is an input to the IF amplifier
after passing through 450kHz
ceramic filter. The typical input
impedance is 1.8kΩ.
IF Decoupling
An external decoupling capacitor
is connected to enhance stability.
FSK Reference Input
This pin is an input of reference
voltage for FSK comparator. An
external capacitor is connected to
create an average DC level of FM
demodulated signal. The choice of
this capacitor is dependent on the
speed of data signal.
A quick charge/discharge circuit
offers the voltage of pin 7 comes
the same voltage of pin 11 quickly.
Ver.2018-03-09
NJM2593
Pin No.
SYMBOL
EQUIVARENT CIRCUIT
VOLTAGE
V+
8
FSK VREF2
0.44V
8
IF OUT
FSK Reference Voltage Output
This pin usually keeps open.
This fixed output voltage may be
available for the FSK reference
voltage of wave shaping comparator
by connecting to pin7. This usage
is effective in shaping the data
signal with continuous bits of the
same polarity, and discussed in
another document related to
applications information.
IF Output
An external phase - shifting
capacitor is connected between
pin9 and pin10.
V+
9
FUNCTION
1.14V
9
40u
Quadrature Detector Input
An external phase - shifting coil or
ceramic discriminator is connected.
V+
10
10
400
400
QUAD IN
1.99V
FM Demodulated Signal Output
An external 3rd order multiple feed
- back filter (RC filter) is connected
between pin11 and pin13.
V+
11
AF OUT
0.44V
11
18u
Ver.2018-03-09
-7-
NJM2593
Pin No.
SYMBOL
EQUIVARENT CIRCUIT
VOLTAGE
V+
12
6u
LPF IN
0.45V
FUNCTION
Low Pass Filter Input
An external RC components
forms a band pass filter between
pin12 and pin13.
This terminal is biased from pin 11
though an external RC filter.
12
Low Pass Filter Output
13
13
LPF OUT
0.45V
V+
14
CHARGE
SW
--
300k
14
V+
6u
15
15
FSK OUT
--
3u
-8-
CARRIER
SENSE
FSK Output
The FSK comparator is a wave
shaping circuit. A Filter Amplifier
output signal is inverted and wave
shaped. Instead of V+, another
power source can also be used
within the limit of the rated supply
voltage.
Carrier Sense Output
This pin outputs the result of RSSI
comparator by comparing RSSI
output level with an external input
level to pin 18.
16
16
Quick Charge / Discharge
Control
The power supply output voltage
to pin 14 sets up the quick charge
/ discharge circuit.
Hi : ON
Low : OFF
Instead of V+, another power
source can also be used within
the limit of the rated supply
voltage.
--
Ver.2018-03-09
NJM2593
Pin No.
SYMBOL
EQUIVARENT CIRCUIT
VOLTAGE
Received Signal Strength
Indicator Output
Pin 11 outputs DC level
proportional to the log of input
signal level to pin 20.
V+
17
RSSI OUT
FUNCTION
0.02V
17
50k
Sense Level Input
External reference voltage of
RSSI comparator
V+
18
SENSE
LEVEL
19
GND
18
--
Ground
-Mixer Input
The mixer is designed to work up
to 470MHz with the typical input
impedance of RinM = 4.5kΩ and
CinM = 2pF(at 21.7MHz).
20
MIX IN
5k
5k
1.03V
20
20p
Note :
1. ESD protection diodes exist between each of the following pins and V+.
Pin 1,2,3,5,6,7,8,9,10,11,12,13,17,18,20
2. ESD protection diodes also exist between each of the following pins and ground.
Pin 1,2,3,5,6,7,8,9,10,11,12,13,14,15,16,17,18
Ver.2018-03-09
-9-
NJM2593
APPLICATION CIRCUIT
Local Oscillator with External Crystal and LC Resonant Elements
RSSI CARRIER FSK
OUT SENSE OUT
1st IF
V
20
19
18
+
V
17
CHARGE
SWITCH
+
16
15
14
+
-
MIXER
Lo
Hi
13
+
11
+
-
RSSI COMP FSK COMP
FILTER AMP
NJM2593
RSSI
BUFFER
12
CHARGE
QUAD
DET
+
-
OSC
IF AMP
1
2
3
4
5
V
6
+
7
8
9
10
+
CDEC
CREF
DET
Tank
V
+
IF Filter
External Local Oscillator Signal Input
RSSI CARRIER FSK
OUT SENSE OUT
V
1st IF
20
19
18
CHARGE
SWITCH
V+
+
17
16
15
14
+
-
MIXER
Lo
Hi
13
+
11
+
-
RSSI COMP FSK COMP
FILTER AMP
NJM2593
RSSI
BUFFER
12
CHARGE
QUAD
DET
+
-
OSC
IF AMP
1
2
3
4
5
V+
6
7
CDEC
8
9
CREF
DET
Tank
External
Oscillator
- 10 -
10
+
V+
IF Filter
Ver.2018-03-09
NJM2593
EVALUATION PC BOARD
The evaluation board is useful for your design and to have more understanding of the usage and performance of
this device. This circuit is the same as TEST CIRCUIT. Note that this board is not prepared to show the
recommendation of pattern and parts layout.
Circuit Diagram
SENSE RSSI CARRIER FSK CHARGE AF
LEVEL OUT SENSE OUT
SW
OUT
Hi
V
R6
100k
RF IN
R11
51
20
19
18
15
14
13
12
C8
3300p
11
FILTER AMP
RSSI
CHARGE
QUAD
DET
+
IF AMP
OSC
2
C1 NC
1000p
LO IN
R3
68k
+
-
RSSI COMP FSK COMP
1
R2
68k
0.01
+
BUFFER
R4
68k
C6
R5
100k
+
-
MIXER
+
C7
560p
C9
1000
p 16
17
C10
1000p
Lo
3
C3 4
1000p
5
C13
10u
R8
51
7
C4
0.1u
8
+
C12 NC
10u
C2
0.1u
B
IF FILTER
6
+
V
A
C2
Position
9
10
C5
22p
V
CD
IF IN
+
R1
3.3k
R9
51
Note:
1. This board is designed for mixer-input type and C2 is factory-configured as follows:
C2
: in the B position
For the case of IF-input type, the position of C2 is necessary to change as follows:
C2
: in the A position
The actual position of C2 is shown in the next page.
2. External components
CD
: Ceramic Discriminator, 450kHz
IF FILTER : Ceramic Filter, 450kHz
Ver.2018-03-09
- 11 -
NJM2593
Circuit Side View
LO IN
RF IN
R8
R11
C1
B Position
SENSE
LEVEL
C9
C2 C2
IC1
NJM2593
C6
C4
C7
C5
C12
RSSI
OUT
R2
R4
IF IN
R9
C1
0
C8
CD
R3
R6
R1
A Position
CARRIER
SENSE
R5
SW
NJM2593
V+
AF OUT
FSK OUT
Hi : Charge ON
Lo: Charge OFF
Ground Side View
C3
CF
C13
C12
Note:
1. External Components
C1, C3, C9, C10=1000pF C2, C4=0.1uF C5=18pF
C6=0.01uF
C12, C13=10uF
R1=3.3kΩ R2, R3, R4=68kΩ R5, R6=100kΩ R8, R9, R11=51Ω
CF : Ceramic Filter, 450kHz
CD : Ceramic Discriminator, 450kHz
- 12 -
C7=560p
C8=3300pF
Ver.2018-03-09
NJM2593
TYPICAL CHARACTERISTICS ( Ta=25°C, V+=2.0V, unless otherwise noted )
Current Consumption versus Supply Voltage
1.5
Measured at Pin3,terminated with 1.8kΩ and 0.1uF
30
Mixer Conversion Gain Gmix(dB)
Current Consumption Iccq(mA)
Mixer Conversion Gain versus Supply Voltage
No Input signal
1.0
0.5
25
20
Fmix=21.7MHz
15
10
5
0
0.0
0
2
4
6
Supply Voltage V+(V)
8
0
10
2
Demodulated Output versus Supply Voltage
10
Condition 1(IF input)
150
60
Duty Ratio of Wave Shaped Output(%)
Demodulated Output Level Vod(mVrms)
8
FSK Duty Ratio vesus Supply Voltage
Condition 1(IF input)
125
100
75
50
25
0
55
CHARGE SW=OFF
50
CHARGE SW=ON
45
40
0
2
4
6
Supply Voltage V+(V)
8
10
0
2
4
6
Supply Voltage V+(V)
8
10
-3dB Limiting Sensitivity versus Supply Voltage
S/N versus Supply Voltage-Mixer InputCondition 2(Mixer input)
Condition 1(IF input)
80
30
Limiting Sensitivity Vin(lim)(dBuVEMF)
70
Signal to Noise Ratio S/N1(dB)
4
6
Supply Voltage V+(V)
60
50
40
30
20
25
20
15
10
5
10
0
0
0
Ver.2018-03-09
2
4
6
Supply Voltage V+(V)
8
10
0
2
4
6
Supply Voltage V+(V)
8
10
- 13 -
NJM2593
Mixer Conversion Gain versus Frequency
Measured at Pin3,terminated with 1.8kΩ and 0.1uF
Mixer Conversion Gain Gmix(dB)
30
25
20
15
10
5
0
10
100
1000
Mixer Input Frequency fmix(MHz)
AF Output versus Frequency:S-Curve
Mixer Conversion Gain versus OSC Input
1200
25
1000
AF Output Voltage(mV)
Mixer Conversion Gain Gmix(dB)
Condition 1(IF input)
Measured at Pin3,terminated with 1.8kΩ and 0.1uF
30
Fmix=21MHz
20
15
10
Fmix=50MHz
800
600
400
5
200
0
60
70
80
90
100
110
0
120
430
Local OSC Input Level (dBuV)
IF Detuning Characterisitics
2.4
IF Detuning(dB)
-5
-10
-15
-20
-25
-30
- 14 -
470
Condition 1(IF input),SENSE LEVEL=0.8V
0
435
450
460
IF Frequency fif(kHz)
Carrier Sense Characteristics
Condition 1(IF input)
RSSI Comparator Output Voltage(V)
5
440
2.0
1.6
1.2
0.8
0.4
0.0
440
445
450
455
IF Frequency fif(kHz)
460
465
0
0.4
0.8
1.2
1.6
RSSI Output Voltage Vrssi(V)
2
Ver.2018-03-09
NJM2593
S+N,N,AMR versus IF Input
S+N,N,AMR versus Mixer Input
Condition 2(Mixer input),AM=30%
10
10
Condition 1(IF input),AM=30%
0
0
S+N
S+N
-10
S+N,N,AMR(dB)
S+N,N,AMR(dB)
-10
-20
-30
AMR
-40
-50
-20
-30
-40
AMR
-50
-60
-60
N
N
-70
-70
-80
-80
-20
0
20
40
60
80
100
Mixer Input Level VinMIX(dBuVEMF)
-20
120
20
40
60
80
100
IF Input Level VinIF(dBuVEMF)
120
RSSI Output versus IF Input
RSSI Output versus Mixer Input
Condition 1(IF input)
Condition 2(Mixer input)
2.0
2.0
1.8
V+=2.0V
1.8
V+=2.0V
RSSI Output Voltage Vrssi(V)
RSSI Output Voltage Vrssi(V)
0
1.6
1.4
1.2
1.0
0.8
0.6
0.4
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.2
0.0
0.0
-20
0
20
40
60
80
100 120
Mixer Input Level VinMIX(dBuVEMF)
-20
0
20
40
60
80
100
IF Input Level VinIF(dBuVEMF)
120
Mixer Conversion Gain versus Temperature
Measured at Pin3,terminated with 1.8kΩ and 0.1uF
Mixer Conversion Gain Gmix(dB)
30
25
20
Fmix=21.7MHz
15
10
5
0
-40
Ver.2018-03-09
-20
0
20
40
60
80
Ambient Temperature Ta(°C)
100
- 15 -
NJM2593
RSSI Output versus Temperature-MixerRSSI Output versus Temperature-MixerCondition 2(Mixer
2(Mixer input)
input)
Condition
2.0
2.0
2.5
2.4
RSSI
RSSI Output
Output Voltage
Voltage Vrssi(V)
Vrssi(V)
RSSI
RSSI Output
Output Voltage
Voltage Vrssi(V)
Vrssi(V)
2.5
2.4
RSSI Output versus Temperature-IFRSSI Output versus Temperature-IF-
70dBuVEMF
70dBuVEMF
60dBuVEMF
1.6
1.5
60dBuVEMF
50dBuVEMF
1.2
50dBuVEMF
40dBuVEMF
40dBuVEMF
30dBuVEMF
1.0
0.8
30dBuVEMF
20dBuVEMF
20dBuVEMF
0.5
0.4
Condition 1(IF
1(IF input)
input)
Condition
2.0
2.0
1.6
1.5
70dBuVEMF
70dBuVEMF
1.2
60dBuVEMF
60dBuVEMF
1.0
0.8
50dBuVEMF
50dBuVEMF
40dBuVEMF
40dBuVEMF
0.5
0.4
30dBuVEMF
20dBuVEMF
0.0
0.0
0.0
-40
-20
00
20
40
60
80
20
40
60
80
Ambient
Ambient Temperature
Temperature Ta(°C)
Ta(°C)
100
100
-40
-40
-20
-20
20
40
60
80
00
20
40
60
80
Ambient Temperature
Temperature Ta(°C)
Ta(°C)
Ambient
100
100
[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.
- 16 -
Ver.2018-03-09