Download MC3362 Low-Power Narrowband FM Receiver

Order this document by MC3362/D
. . . includes dual FM conversion with oscillators, mixers, quadrature
discriminator, and meter drive/carrier detect circuitry. The MC3362 also has
buffered first and second local oscillator outputs and a comparator circuit for
FSK detection.
• Complete Dual Conversion Circuitry
•
•
•
•
•
•
•
LOW–POWER
DUAL CONVERSION
FM RECEIVER
SEMICONDUCTOR
TECHNICAL DATA
Low Voltage: VCC = 2.0 to 6.0 Vdc
Low Drain Current (3.6 mA (Typical) @ VCC = 3.0 Vdc)
Excellent Sensitivity: Input Voltage 0.6 µVrms (Typical)
for 12 dB SINAD
Externally Adjustable Carrier Detect Function
P SUFFIX
PLASTIC PACKAGE
CASE 724
Low Number of External Parts Required
Manufactured Using Motorolais MOSAICr Process Technology
MC13135 is Preferred for New Designs
DW SUFFIX
PLASTIC PACKAGE
CASE 751E
(SO-24L)
Figure 2. Pin Connections and
Representative Block Diagram
Figure 1. Simplified Application in a PLL Frequency
Synthesized Receiver
RF Input
to 200 MHz
1st Mixer Input 1
Figure 2.
2nd LO Output 2
Input
Match
0.01
VCC
120 pF
50 pF
10.245 MHz
Ceramic Filter
455 kHz
10 k
2
23
0.1
From PLL Phase
Detector
22 1st LO Tank
2nd LO Base 4
21 1st LO Tank
2nd Mixer Output 5
0.01
4
21
Limiter Input 7
20
Limiter
8
Decoupling
Limiter
9
Decoupling
6
19
7
18
8
17
9
16
10
15
11
14
12
13
X
20 1st LO Output
19 1st Mixer Output
VCC 6
22
0.41 µH
To PLL or Prescaler
Ceramic Filter
10.7 MHz
18 2nd Mixer Input
17 2nd Mixer Input
16 VEE
15 Comparator Output
Meter Drive 10
1.0 +
14 Comparator Input
Carrier Detect 11
10 k
0.1
Data
Quadrature Coil 12
Lp = 680 µH
Cp = 180 pF
8.2 k
X
13 Detector Output
VCC
0.001
39 K
23 Varicap Control
2nd LO Emitter 3
3
MC3362
200 k
To Carrier
Detect
Indicator
24
5
0.1
0.1
1
24 1st Mixer Input
X
ORDERING INFORMATION
Recovered
0.01 Audio
Device
MC3362DW
MC3362P
Operating
Temperature Range
TA = – 40 to +85°C
Package
SO–24L
Plastic DIP
 Motorola, Inc. 1995
MOTOROLA ANALOG IC DEVICE DATA
1
MC3362
MAXIMUM RATING (TA = 25°C, unless otherwise noted)
Pin
Symbol
Value
Unit
Power Supply Voltage (See Figure 2)
6
VCC(max)
7.0
Vdc
Operating Supply Voltage Range (Recommended)
6
VCC
2.0 to 6.0
Vdc
1, 24
V1–24
1.0
Vrms
Junction Temperature
–
TJ
150
°C
Operating Ambient Temperature Range
–
TA
– 40 to + 85
°C
Storage Temperature Range
–
Tstg
– 65 to + 150
°C
Rating
Input Voltage (VCC
q 5.0 Vdc)
ELECTRICAL CHARACTERISTICS (VCC = 5.0 Vdc, fo = 49.7 MHz, Deviation = 3.0 kHz, TA = 25°C, Test Circuit of Figure 3,
unless otherwise noted)
Characteristic
Drain Current (Carrier Detect Low – See Figure 5)
Pin
Min
Typ
Max
6
Units
–
4.5
7.0
mA
Input for – 3.0 dB Limiting
–
0.7
2.0
µVrms
Input for 12 dB SINAD (See Figure 9)
–
0.6
–
µVrms
–
450–j350
–
Ω
Recovered Audio (RF signal level = 10 mV)
13
–
350
–
mVrms
Noise Output (RF signal level = 0 mV)
13
–
250
–
mVrms
Carrier Detect Threshold (below VCC)
10
–
0.64
–
Vdc
Meter Drive Slope
10
–
100
–
nA/dB
Input for 20 dB (S + N)/N (See Figure 7)
–
0.7
–
µVrms
First Mixer 3rd Order Intercept (Input)
–
–22
–
dBm
First Mixer Input Resistance (Rp)
–
690
–
Ω
First Mixer Input Capacitance (Cp)
–
7.2
–
pF
Conversion Voltage Gain, First Mixer
–
18
–
dB
Conversion Voltage Gain, Second Mixer
–
21
–
–
1.4
–
Series Equivalent Input Impedence
Dector Output Resistance
13
RF
Input
kΩ
Figure 3. Test Circuit
Ferronics
12–345–K
50 Ω
120 pF
10.245
MHz
2:6
50 pF
1
24
2
23
3
22
4
21
6
0.1
0.1
68 kΩ
180 pF
VCC
10.5 Turns
Coilcraft
UNI–10/142
33 pF
20
5
FL1
0.01
MC3362
7
18
8
17
9
16
10
15
11
14
12
13
Toko RMC–2A6597HM
FL1:
muRata CFU455D
or
Toko LFC–4551
19
FL2
0.1
1.0 µF
+
FL2:
muRata SFE10.7MA
or
Toko SK107M3–A0–10
VEE
NOTE: See AN980 for Additional Design Information.
2
MOTOROLA ANALOG IC DEVICE DATA
MC3362
Figure 5. Drain Current, Recovered Audio
versus Supply
Figure 4. IMeter versus Input
8.0
11
VCC
10
10
MC3362
700
ICC, Carr. Det. Low (RF in = 10 mV)
6.0
5.0
8.0
I CC (mA)
I10 ( µ A)
7.0
A
9.0
800
7.0
6.0
5.0
400
300
3.0
Recovered Audio
3.0
2.0
200
1.0
100
0
2.0
– 130 – 120 – 110 – 100 – 90 – 80 – 70 – 60 – 50 – 40 – 30
RF INPUT (dBm)
0
Figure 6. Signal Levels
20
10
10
0
S + N, N, AMR (dB)
20
Second Mixer Output
– 10
First Mixer Output
– 20
Second Mixer Input
– 30
1.0
2.0
3.0
4.0
VCC (V)
5.0
6.0
7.0
0
8.0
Figure 7. S + N, N, AMR versus Input
30
0
POWER (dBm)
500
ICC, Carr. Det. High (RF in = 0 mV)
4.0
4.0
– 40
– 50
600
V13 (mVrms)
12
First Mixer Input
S+N
– 10
– 20
– 30
S + N 30% AM
– 40
– 50
MC3362 13 10 k
– 60
0.01
N
10 k
0.01
– 60
– 70
RF Input to Transformer
– 70
– 130 – 120 – 110 – 100 – 90 – 80 – 70 – 60 – 50 – 40 – 30
RF INPUT (dBm)
– 80
– 130 – 120 – 110 – 100 – 90 – 80 – 70 – 60
RF INPUT (dBm)
Figure 8. 1st Mixer 3rd Order Intermodulation
– 50 – 40
– 30
Figure 9. Detector Output versus Frequency
4.0
20
10
0
3.0
– 10
V13 (Vdc)
dB
– 20
– 30
– 40
– 50
Desired Products
3rd Order Intermod.
Products
– 60
2.0
1.0
– 70
– 80
– 100 – 90
– 80
– 70 – 60 – 50 – 40 – 30
RF INPUT (dBm)
MOTOROLA ANALOG IC DEVICE DATA
– 20 – 10
0
0
– 40
– 30
– 20
– 10
0
10
20
RELATIVE INPUT FREQUENCY (kHz)
30
40
3
MC3362
Figure 10. PC Board Test Circuit
(LC Oscillator Configuration Used in PLL Synthesized Receiver)
18 p
RF Input
49.67 MHz
50 Ω
1000 p
24
1
0.01
0.47 µ
p p VCC)
Varactor Control
(keep 0.7 V V23
23
2
0.01
VCC = 2.0 to 7.0 Vdc
120 p
3
22
4
21
10.245, Fund. Mode
32 pF Load
5
20
455 kHz
Cer. Filt.
0.41 µ
33 p
50 p
First Local Oscillator
Buffered Output
3.0 k
VCC
CRF1
6
19
7
18
CRF2
0.1
0.1
8
17
9
16
10
15
0.1
(This network must be tuned to exactly
10.7 MHz above or below the incoming
RF signal.
NOTE: The IF is rolled off above 10.7
MHz to reduce L.O. feedthrough.)
to VCC
CRF1 = muRata CFU 455X – the X
suffix denotes 6.0 dB bandwidth.
Rin = Rout = 1.5 to 2.0 kΩ.
1
CRF2 = muRata SFA10.7 MF5 or
SFE10.7 or equivalent. Rin = Rout
= 330 Ω . Crystal filters can be
used but impedance matching will
need to be added to ensure proper
filter characteristics are realized.
10.7 MHz
Cer. Filt.
0.1
100 k
51 k
10 k
CD Adjust
10 k
Carrier
Detect
39 k
–+
11
14
FSK Data Output
(optional)
0.001
12
13
8.2 k
455 kHz
LC Resonator
0.01
Recovered
Audio
(MC3362)
Figure 10A. Crystal Oscillator Configuration for Single Channel Application
MC3362
23
22
20 k
0.68 µ
VCC
300
21
0.68 µ
Crystal used is series mode resonant
(no load capacity specified), 3rd overtone.
This method has not proven adequate for
fundamental mode, 5th or 7th overtone crystals.
The inductor and capacitor will need to be
changed for other frequency crystals. See
AN980 for further information.
20 k
38.97 MHz
4
MOTOROLA ANALOG IC DEVICE DATA
MC3362
Figure 11. Component Placement View
Showing Crystal Oscillator Circuit
Figure 11A. LC Oscillator Component View
L.O.OUT
1
.047
1
.2K
3
METER
DRIVE
DATA
L.O.OUT
GND
4
TOKO
55VLC06379GT
5
CONTROL
CONTROL
330
1
3K
3
10.7MHz
CF
10K
68K
3
8.2 K
2
10K
3K
2
.01
.047
CARRIER
DETECT
10K
10K
.1
.1
51K
.41 µH
7
33p
CF
455KHz
.1
2
.68
µH
39 MHz
XT
10.7 MHz
CF
.1
100K
.01
.01
50p
MC3362P
18p
Vcc
120p
10.245MHz
XT
1.
.68
µH
1Kp
.47 µH
.01
.01
INPUT
8
REC. AUDIO
NOTES: 1. Recovered Audio components may be deleted when using
data output.
2. Carrier Detect components must be deleted in order to obtain
linear Meter Drive output. With these components in place the
Meter Drive outputs serve only to trip the Carrier Detect indicator.
3. Data Output components should be deleted in applications
where only audio modulation is used. For combined audio/data
applications, the 0.047 µF coupling capacitor will add distortion
to the audio, so a pull–down resistor at pin 13 may be required.
4. Use Toko 7MC81282 Quadrature coil.
5. Meter Drive cannot be used simultaneously with Carrier Detect output.
For analog meter drive, remove components labelled ″2″ and measure
meter current (4–12 µA) through ammeter to VCC.
6. Either type of oscillator circuit may be used with any output circuit
configuration.
7. LC Oscillator Coil: Coilcraft UNI 10/42 10.5 turns, 0.41 µH Crystal
Oscillator circuit: trim coil, 0.68 µH. Coilcraft M1287–A.
8. 0.47 H, Coilcraft M1286–A. Input LC network used to match first mixer
input impedance to 50 Ω .
CIRCUIT DESCRIPTION
The MC3362 is a complete FM narrowband receiver from
antenna input to audio preamp output. The low voltage dual
conversion design yields low power drain, excellent
sensitivity and good image rejection in narrowband voice and
data link applications.
In the typical application (Figure 1), the first mixer
amplifies the signal and converts the RF input to 10.7 MHz.
This IF signal is filtered externally and fed into the second
mixer, which further amplifies the signal and converts it to a
455 kHz IF signal. After external bandpass filtering, the low IF
is fed into the limiting amplifier and detection circuitry. The
audio is recovered using a conventional quadrature detector.
Twice–IF filtering is provided internally.
The input signal level is monitored by meter drive circuitry
which detects the amount of limiting in the limiting amplifier.
The voltage at the meter drive pin determines the state of the
carrier detect output, which is active low.
APPLICATIONS INFORMATION
The first local oscillator can be run using a free–running
LC tank, as a VCO using PLL synthesis, or driven from an
external crystal oscillator. It has been run to 190 MHz.* A
buffered output is available at Pin 20. The second local
oscillator is a common base Colpitts type which is typically
run at 10.245 MHz under crystal control. A buffered output is
available at Pin 2. Pins 2 and 3 are interchangeable.
The mixers are doubly balanced to reduce spurious
responses. The first and second mixers have conversion
gains of 18 dB and 22 dB (typical), respectively, as seen in
Figure 6. Mixer gain is stable with respect to supply voltage.
For both conversions, the mixer impedances and pin layout
are designed to allow the user to employ low cost, readily
available ceramic filters. Overall sensitivity and AM rejection
are shown in Figure 7. The input level for 20 dB (S + N)/N is
0.7 µV using the two–pole post–detection filter pictured.
* If the first local oscillator (Pins 21 and/or 22) is driven from a
strong external source (100 mVrms), the mixer can be used to
over 450 MHz.
MOTOROLA ANALOG IC DEVICE DATA
5
MC3362
to ensure data integrity and avoid adjacent channel “splatter.”
Hysteresis is available by connecting a high valued resistor
from Pin 15 to Pin 14. Values below 120 kΩ are not
recommended as the input signal cannot overcome the
hysteresis.
The meter drive circuitry detects input signal level by
monitoring the limiting amplifier stages. Figure 4 shows the
unloaded current at Pin 10 versus input power. The meter
drive current can be used directly (RSSI) or can be used to
trip the carrier detect circuit at a specified input power. To do
this, pick an RF trip level in dBm. Read the corresponding
current from Figure 4 and pick a resistor such that:
Following the first mixer, a 10.7 MHz ceramic band–pass
filter is recommended. The 10.7 MHz filtered signal is then
fed into one second mixer input pin, the other input pin being
connected to VCC. Pin 6 (VCC) is treated as a common point
for emitter–driven signals.
The 455 kHz IF is typically filtered using a ceramic
bandpass filter then fed into the limiter input pin. The limiter
has 10 µV sensitivity for – 3.0 dB limiting, flat to 1.0 MHz.
The output of the limiter is internally connected to the
quadrature detector, including a quadrature capacitor. A
parallel LC tank is needed externally from Pin 12 to VCC. A 39
kΩ shunt resistance is included which determines the peak
separation of the quadrature detector; a smaller value will
increase the spacing and linearity but decrease recovered
audio and sensitivity.
A data shaping circuit is available and can be coupled to
the recovered audio output of Pin 13. The circuit is a
comparator which is designed to detect zero crossings of
FSK modulation. Data rates are typically limited to 1200 baud
'
R10
0.64 Vdc / I10
Hysteresis is available by connecting a high valued resistor
RH between Pins 10 and 11. The formula is:
Hysteresis = VCC/(RH x 10 – 7 ) dB
INPUT
Figure 12. Circuit Side View
MC3362P
GND
L.O. OUT
CARRIER
DETECT
VCC
CONTROL
4I
REC. AUDIO
METER
DRIVE
DATA
4I
6
MOTOROLA ANALOG IC DEVICE DATA
MOTOROLA ANALOG IC DEVICE DATA
7
2.0 kΩ
8
9
bias
21
23
bias
1
20
1.0
kΩ
1.0 kΩ
24
10
100 Ω
12
2
3
4
6 VCC
bias
Figure 13. Representative Schematic Diagram
17
400
Ω
16
13
bias
14
bias
18
VEE
400 Ω
15
11
1.4 kΩ
5
MC3362
7
MC3362
OUTLINE DIMENSIONS
P SUFFIX
PLASTIC PACKAGE
CASE 724–03
ISSUE D
–A–
24
13
1
12
NOTES:
1. CHAMFERED CONTOUR OPTIONAL.
2. DIMENSION L TO CENTER OF LEADS WHEN
FORMED PARALLEL.
3. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
4. CONTROLLING DIMENSION: INCH.
–B–
L
C
–T–
NOTE 1
K
SEATING
PLANE
N
E
G
M
J
F
D
24 PL
0.25 (0.010)
24 PL
0.25 (0.010)
M
T A
13
–B–
M
M
12X
M
B
M
12
24X
D
J
0.010 (0.25)
M
T A
S
B
S
F
R
C
–T–
SEATING
PLANE
M
22X
INCHES
MIN
MAX
1.230
1.265
0.250
0.270
0.145
0.175
0.015
0.020
0.050 BSC
0.040
0.060
0.100 BSC
0.007
0.012
0.110
0.140
0.300 BSC
0_
15_
0.020
0.040
MILLIMETERS
MIN
MAX
31.25
32.13
6.35
6.85
3.69
4.44
0.38
0.51
1.27 BSC
1.02
1.52
2.54 BSC
0.18
0.30
2.80
3.55
7.62 BSC
0_
15_
0.51
1.01
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2. CONTROLLING DIMENSION: MILLIMETER.
3. DIMENSIONS A AND B DO NOT INCLUDE
MOLD PROTRUSION.
4. MAXIMUM MOLD PROTRUSION 0.15 (0.006)
PER SIDE.
5. DIMENSION D DOES NOT INCLUDE DAMBAR
PROTRUSION. ALLOWABLE DAMBAR
PROTRUSION SHALL BE 0.13 (0.005) TOTAL IN
EXCESS OF D DIMENSION AT MAXIMUM
MATERIAL CONDITION.
P
0.010 (0.25)
1
T B
DW SUFFIX
PLASTIC PACKAGE
CASE 751E–04
(SO-24L)
ISSUE E
–A–
24
M
DIM
A
B
C
D
E
F
G
J
K
L
M
N
X 45 _
DIM
A
B
C
D
F
G
J
K
M
P
R
MILLIMETERS
MIN
MAX
15.25
15.54
7.40
7.60
2.35
2.65
0.35
0.49
0.41
0.90
1.27 BSC
0.23
0.32
0.13
0.29
0_
8_
10.05
10.55
0.25
0.75
INCHES
MIN
MAX
0.601
0.612
0.292
0.299
0.093
0.104
0.014
0.019
0.016
0.035
0.050 BSC
0.009
0.013
0.005
0.011
0_
8_
0.395
0.415
0.010
0.029
K
G
Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty, representation or guarantee regarding
the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit,
and specifically disclaims any and all liability, including without limitation consequential or incidental damages. “Typical” parameters can and do vary in different
applications. All operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. Motorola does
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associated with such unintended or unauthorized use, even if such claim alleges that Motorola was negligent regarding the design or manufacture of the part.
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8
◊
*MC3362/D*
MC3362/D
MOTOROLA ANALOG IC DEVICE
DATA