SONY CXA3179N

CXA3179N
IF Amplifier for M-ary FSK Pagers (AFC Supported)
Description
The CXA3179N is a low current consumption FM
IF amplifier which employs the newest bipolar
process. It is suitable for M-ary FSK pagers using
AFC.
24 pin SSOP (Plastic)
Features
• Low current consumption : 1.1 mA
(typ. at VCC=1.4 V)
• Low voltage operation : VCC=1.1 to 4.0 V
• Small package 24-pin SSOP
• Second mixer and oscillator
• Needless of IF decoupling capacitor
• Reference power supply for operational amplifier
and comparator
• Bit rate filter with variable cut-off
• AFC current output circuit
• RSSI function
• IF input, VCC standard
• Maximum input frequency : 30 MHz
Absolute Maximum Ratings
• Supply voltage
VCC
• Operating temperature Topr
• Storage temperature
Tstg
• Allowable power dissipation
PD
Operating Condition
Supply voltage
VCC
7.0
–20 to +75
–65 to +150
417
V
°C
°C
mW
1.1 to 4.0
V
Applications
• M-ary FSK pagers
• Double conversion pagers
Structure
Bipolar silicon monolithic IC
MIX IN
GND
REG OUT
REG CONT
LVA OUT
NRZ OUT
AFC C.
B.S.
AUDIO
L.C. OUT
AFC OFF
RSSI
Block Diagram and Pin Configuration
24
23
22
21
20
19
18
17
16
15
14
13
RSSI
LEVEL
COMP
LVA
GND
REG
AFC
MIX
QUAD_DET
1
2
3
4
5
6
7
8
9
10
11
12
MIX OUT
VCC
IF IN
TH CONT
AFC
QUAD
C1
C2
C3
FIL SW
FILTER
OSC OUT
IF_LIM
OSC IN
OSC
Sony reserves the right to change products and specifications without prior notice. This information does not convey any license by
any implication or otherwise under any patents or other right. Application circuits shown, if any, are typical examples illustrating the
operation of the devices. Sony cannot assume responsibility for any problems arising out of the use of these circuits.
—1—
E96Y06A8Z
CXA3179N
Pin Description
Pin
No.
1
Symbol
OSC IN
Pin
voltage
1.4 V
Equivalent circuit
Description
15k
VCC
300
72
15k
1
2
2
OSC OUT
0.7 V
Connects the external parts of crystal
oscillator circuit.
A capacitor and crystal oscillator are
connected to these pins and VCC.
GND
VCC
1.5k
Mixer output.
Connect a 455 kHz ceramic filter
between this pin and IF IN.
3
3
MIX OUT
1.3 V
GND
4
VCC
Power supply.
1.5k 20k
5
IF IN
1.4 V
VCC
1.5k
20k
5
IF limiter amplifier input.
GND
VCC
6
TH CONT
—
6
25k
GND
Determines the level comparator
threshold value.
Threshold value can be adjusted by
inserting the resistor between Pin 6 and
VCC.
Normally, short to VCC.
VCC
72
7
AFC
—
7
AFC current output.
GND
VCC
20k
8
QUAD
1.4 V
22k
Connects the phase shifter of FM
detector circuit.
8
20p
GND
—2—
CXA3179N
Pin
No.
Symbol
Pin
voltage
Equivalent circuit
Description
VCC
9
10
11
C1
C2
C3
0.2 V
Connects the capacitor that determines
the LPF cut-off.
9
10
35k
50k
11
GND
12
72
Switches the LPF cut-off.
Cut-off is decreased by setting this pin
high.
(Applied voltage range :
–0.5 V to +7.0 V)
20k
12
FIL SW
—
140k
GND
VCC
7k
13
RSSI
0.1 V
7k
RSSI circuit output.
13
70k
GND
14
72
20k
14
AFC OFF
Sets off the AFC circuit current.
The AFC current is off by setting Pin 18
low and Pin 14 high.
—
100k
GND
15
19
15
19
20
L.C. OUT
NRZ OUT
LVA OUT
—
—
—
72
Level comparator, NRZ comparator
and LVA comparator outputs. They are
open collectors.
(Applied voltage range :
–0.5 V to +7.0 V)
20
GND
VCC
Level comparator and NRZ comparator
inputs.
The filter circuit output is connected.
72
16
AUDIO
0.2 V
16
72
GND
—3—
CXA3179N
Pin
No.
Symbol
Pin
voltage
Equivalent circuit
Description
17
Controls the battery saving.
Setting this pin low suspends the
operation of IC.
(Applied voltage range :
–0.5 V to +7.0 V)
72
20k
17
B.S.
—
140k
GND
20k
18
18
AFC C.
—
100k
GND
Controls the time constant of the AFC
circuit. Set this pin high to make the
short time constant.
(Applied voltage range :
–0.5 V to +7.0 V)
VCC
21
REG
CONT
Output for internal constant-voltage
source amplifier.
Connect the base of PNP transistor.
(Current capacity : 100 µA)
72
—
21
GND
VCC
22
REG OUT
1.0 V
Constant-voltage source output.
Controlled to maintain 1.0 V.
78k
22
1k
22k
GND
23
GND
—
Ground
VCC
2k
4.16k 4.16k
24
MIX IN
1.4 V
Mixer input.
24
GND
—4—
CXA3179N
Electrical Characteristics
(VCC=1.4 V, Ta=25 °C, FS=21.7 MHz, FMOD=1.6 kHz, FDEV=4.8 kHz, AMMOD=30 %)
Item
Current consumption
Current consumption
AM rejection ratio
NRZ output saturation voltage
NRZ output leak current
Symbol
ICC
ICCS
AMRR
VSATNRZ
ILNRZ
NRZ hysteresis width
VTWNRZ
VB output current
VB output saturation voltage
REG OUT voltage
IOUT
VSATVB
VREG
LVA operating voltage
VLVA
LVA output leak current
LVA output saturation voltage
Detector output voltage
Logic input voltage high level
Logic input voltage low level
ILLVA
VSATLVA
VODET
VTHBSV
VTLBSV
Limiting sensitivity
VIN (LIM)
Detector output level ratio
deviation to level comparator
window width
Level comparator
output saturation voltage
Level comparator
output leak current
RSSI output offset
Mixer input resistance
Mixer output resistance
IF limiter input resistance
Conditions
Measurement circuit 1,
Measurement circuit 1,
Measurement circuit 2,
Measurement circuit 4,
Measurement circuit 3,
Measurement circuit 3,
Vin=0.1 to 0.3 V
Measurement circuit 5
Measurement circuit 5
Output current 0 µA
Measurement circuit 6,
V1=1.4 to 1.0 V
Measurement circuit 6,
Measurement circuit 7
Measurement circuit 2
—
—
Measurement circuit 2,
Data filter fc=2.4 kHz
V2=1.0 V
V2=0 V
30 k LPF
Vin=0.3 V
Vin=0.1 V
V1=1.0 V
Min.
0.7
—
25
—
—
Typ.
1.1
6
—
—
—
Max.
1.35
10
—
0.4
5.0
Unit
mA
µA
dB
V
µA
0
10
20
mV
100
—
0.95
—
—
1.00
—
0.4
1.05
µA
V
V
1.00
1.05
1.10
V
—
—
—
—
2.0
0.4
µA
V
50
0.9
—
63
—
—
80
—
0.35
mVrms
—
–108
—
dBm
–15
0
+15
%
V
V
VLCWR
When Pin 6 is shorted to VCC
VSATLC
Measurement circuit 9
—
—
0.4
V
ILLC
Measurement circuit 8
—
—
2.0
µA
VORSSI
RINLIM
ROUTMIX
RINLIM
Measurement circuit 10
—
—
—
—
1.6
1.2
1.2
150
2.0
1.5
1.5
300
2.4
1.8
1.8
mV
kΩ
kΩ
kΩ
—5—
CXA3179N
Electrical Characteristics Measurement Circuit
Vin
10p to
120p
V2
24
1
23
22
2
3
21
20
4
5
19
6
18
7
17
8
16
9
15
10
14
11
13
V2
1V
1.8µ
V
1000p
24
23
22
21
20
19
18
17
16
15
14
13
1
2
3
4
5
6
7
8
9
10
11
12
12
VCC
A
V1
1.4V
15p
1µ
VCC
V1
1.4V
Measurement circuit 1
A
100k
1200p
Measurement circuit 2
50µA
V2
1V
V
8.2k
1200p
1200p
22p
V2
1V
V
24
23
22
21
20
19
18
17
16
15
14
13
24
23
22
21
20
19
18
17
16
15
14
13
1
2
3
4
5
6
7
8
9
10
11
12
1
2
3
4
5
6
7
8
9
10
11
12
Vin
V1
1.4V
VCC
VCC
Vin
V1
1.4V
Measurement circuit 3
100µA
V3
0.5V
Measurement circuit 4
GND
A
V2
1V
V
V2
1V
V
100k
24
23
22
21
20
19
18
17
16
15
14
13
24
23
22
21
20
19
18
17
16
15
14
13
1
2
3
4
5
6
7
8
9
10
11
12
1
2
3
4
5
6
7
8
9
10
11
12
VCC
GND
VCC
V1
1.4V
Measurement circuit 5
—6—
V1
1.4 to 1.0V
Measurement circuit 6
CXA3179N
50µA
A
V2
1V
V2
1V
V
V
100k
24
23
22
21
20
19
18
17
16
15
14
13
24
23
22
21
20
19
18
17
16
15
14
13
1
2
3
4
5
6
7
8
9
10
11
12
1
2
3
4
5
6
7
8
9
10
11
12
VCC
Vin
0.2V
V1
1.4V
VCC
V1
1.4V
Measurement circuit 7
V2
1V
50µA
V2
1V
V
24
23
22
21
20
19
18
17
16
15
14
13
1
2
3
4
5
6
7
8
9
10
11
12
VCC
V1
1.4V
Measurement circuit 8
Vin
0.1V
—7—
V
24
23
22
21
20
19
18
17
16
15
14
13
1
2
3
4
5
6
7
8
9
10
11
12
VCC
Measurement circuit 9
100P
V1
1.4V
Measurement circuit 10
VCC
P1
RF SMA
1
24
1000P
C4
22P
OSC
GND
2
MIX
23
GND
GND
REG
P7
PNP
GND
3
22
R4
0.01µ
20
R6
4
REG
5
LVA
19
6
IF_LIM
VB_REG NRZ
COMP
21
GND
AFC
GND
7
AFC C.
18
GND
8
GND
9
15
10
FILTER
AUDIO COMP
OUT
16
LEVEL
COMP
BS
QUAD_DET
17
GND
RSSI
P3
12
FIL SW
RSSI
13
GND
GND
AFC
OFF
GND
11
14
GND
1000P
Application circuits shown are typical examples illustrating the operation of the devices. Sony cannot assume responsibility for
any problems arising out of the use of these circuits or for any infringement of third party patent and other right due to same.
GND
L1
10P to 120P
1.8µH
C3
XTAL
C6
C5
C1
15P
10µ
C7
220
10µ
C8
LVA
C6
NRZ
P5
100k
GND
1µ
P6
0.01µ
S3
DISK
LEVEL
P4
S2
1420P
(1200P+220P)
R5
CERAFIL
S4
C10
P8
R7
R8
C11
680P
100k
P9
AFC
1100P
(100P+1000P)
6.8K
100k
C12
—8—
S1
GND
C13
C14
AUDIO
P2
Application Circuit
CXA3179N
CXA3179N
Application Notes
1) Power Supply
The CXA3179N, with built-in regulator, is designed to permit stable operation at a wide range of supply
voltage from 1.1 to 4.0 V. Decouple the wiring to VCC (Pin 4) as close to the pin as possible.
2) Oscillator Input
Oscillator input method
a) Using Pins 1 and 2, input a self-excited oscillation signal through the composition of a Colpitts type
crystal oscillator circuit.
b) Directly input a local oscillation signal to Pin 1.
1
2
1
3
2
Ceramic
filter
VCC
3
Ceramic
filter
From
local signal
Fig. 1
3) Mixer
The mixer is of double-balance type. Pin 24 is the input pin. Input though a suitable matching circuit. The
input impedance is 2.0 kΩ.
Pin 3 serves as the output pin for the mixer, and a load resistance of 1.5 kΩ is incorporated.
4) IF Filter
The filter to be connected between this mixer output and the IF limiter amplifier input should have the
following specifications.
I/O impedance
: 1.5 kΩ ±10 %
Band width
: Changes according to applications.
5) IF Limiter Amplifier
The gain of this IF limiter amplifier is approximately 100 dB. Take notice of the following points in making
connection to the IF limiter amplifier input pin (Pin 5).
a) Wiring to the IF limiter amplifier input (Pin 5) should be as short as possible.
b) As the IF limiter amplifier output appears at QUAD (Pin 8), wiring to the ceramic discriminator
connected to QUAD should be as short as possible to reduce the interference with the mixer output and
IF limiter amplifier input.
3
4
5
6
7
8
VCC
Wire as short and apart as possible
Fig. 2
—9—
As short as possible
9
CXA3179N
6) Quick Charge
In order to hasten the Pin 7 rising time from when power is turned on, the CXA3179N features a quick
charge circuit. The capacitance value connected to Pin 7 should be chosen such that the voltage does not
vary much due to discharge during battery saving.
Connect a signal for controlling the quick charge circuit to Pin 18. Setting this pin high enables the quick
charge mode, and setting this pin low enables the steady-state reception mode. Quick charge is used
when the power supply is turned on. The battery saving must be set high at the time.
Connect Pin 18 to GND when quick charge is not being used.
Power supply to the IC
(Pin 4)
Quick charge
(Pin 18)
5ms
Battery saving control
(Pin 17)
1ms
A
T2
T1
T3
T4
Fig. 3
Example when the Pin 7 REF capacitance value is 1 µF
T1 in Fig. 3 : 2-level data setting time after quick charge
0 ms
T2 in Fig. 3 : 4-level data setting time after quick charge
2 ms or less
T3 in Fig. 3 : 4-level data can be obtained
T4 in Fig. 3 : 2-level data can be obtained
—10—
1ms
CXA3179N
7) Detector
The detector is of quadrature type. To perform phase shift, connect a ceramic discriminator to Pin 8.
The phase shifting capacitor for the quadrature detector is incorporated. The FM (FSK) signal
demodulated with the detector will be output to AUDIO (Pin 16) through the internal LPF.
The AUDIO output is the anti-phase output to the NRZ OUT.
The CDBM455C50 (MURATA MFG. CO., LTD.) ceramic discriminator is recommended for the CXA3179N.
For the 2-level system, the CDBM455C28 can also be used.
7
8
9
6.5k
Ceramic
discriminator
CDBM455C50
VCC
Fig. 4
The detector output level is changed according to the resistance value connected to Pin 8.
8) Filter Buffer, Level Comparator and NRZ Comparator
The LPF circuit is built in this IC.
The LPF output is connected internally to the NRZ comparator, level comparator and quick charge circuit.
19
16
15
L.C.
LPF
0.2V
DET
7
Fig. 5
Using the LPF, remove the noise from the demodulated signal and input the signal to the above three
circuits.
—11—
CXA3179N
8) -1. LPF Constant
The composition of the data filter is ternary.
The first-stage cut-off fC1 is
fC1 =
1
2πC11R
The second-stage cut-off fC2 is
fC2 =
1
2πR√C12 C13
C11, C12, C13 :
R :
,
Q =
C12
C13
External capacitance shown in the Application Circuit
IC internal resistance
The Butterworse characteristic is for C12=C13=C14.
R is approximately 55 kΩ ±20 % when Pin 12 is low. The table below shows the example of constants to
data rate.
Pin 12 filter switch
Capacitance (pF)
H
L
H
L
H
L
H
L
6800
1500
PIN9 1100 P
PIN10 680 P
PIN11 1420 P
PIN9 1100 P
PIN10 680 P
PIN11 1420
fc (Hz)
—
430
950
1900
Data rate
—
512 bps (2 levels)
1200 bps (2 levels)
2400 bps (2 levels)
1000
1600 bps (2 levels)
2000
3200 bps (2 levels)
1000
3200 bps (4 levels)
2000
6400 bps (4 levels)
8) -2. Comparator Output
The level comparator and the NRZ comparator shape the waveform of this input signal and output it as a
square wave. The comparator output stage is for open collector.
Thus, if the CPU is of CMOS type and the supply voltage is different, a direct interface as illustrated in the
figure below can be implemented.
VCC 1.4V
VCC
4
CMOS power supply
(15)
CMOS IC
19
Comparator output
Fig. 6
—12—
CXA3179N
8) -3. Level Comparator Output
The level comparator characteristics are as shown in the figure below. Therefore, a high signal is output at
the bit border even if the input signal is a ±4.8 kHz signal. This high output interval varies according to the
frequency response of the bit rate filter, and widens as the cut-off frequency becomes lower. The decoder
avoids this high interval when processing data.
Input signal
H
Output
L
–4.8
–1.6
f0
+1.6
Level comparator output
+4.8
Input frequency deviation [kHz]
9) REG CONT
Controls the base bias of the external transistors.
10) LVA OUT
This pin goes high (open) when the supply voltage becomes lower. Since the output is an open collector, it
can be used to directly drive the CMOS device. The setting voltage of the LVA is 1.05 V (typ.), and it
possesses a hysteresis with respect to the supply voltage. The hysteresis width is 50 mV (typ.).
11) B.S.
Operation of the CXA3179N can be halted by setting this pin low. This pin can be connected directly to the
CMOS device. The current consumption for battery saving is 10 µA or less (at 1.4 V).
B.S.
17
Fig. 7
—13—
CXA3179N
12) M-ary (M=2- or 4-level) FSK Demodulation System
12)-1. Output Waveform
Polarity discrimination output and level comparator output are used to demodulate the 4-level waveform
shown below.
[4-level FSK demodulating waveform]
+4.8kHz
+1.6kHz
–1.6kHz
01
00
10
11
01
10
00
–4.8kHz
[NRZ OUT] Polarity discrimination output
(When the input frequency is higher than the local frequency)
POS
0
0
1
1
0
1
0
1
0
0
1
1
0
0
The polarity can be inverted
by setting the local frequency
higher than the input
frequency.
NEG
[L.C. OUT] Level comparator output
1.6kHz
4.8kHz
The 4-level FSK demodulating data is divided into an NRZ OUT and L.C. OUT shown above. Here, the
NRZ OUT corresponds to a conventional NRZ comparator output. The L.C. OUT is made comparing the
demodulated waveform amplitude to the IC internal reference voltage levels. When the threshold value of
L.C. OUT is not appropriate to the detector output, the resistance value on Pin 8 should be varied for the
detector output level adjustment or the resistor should be inserted between Pin 6 and VCC for the level
comparator threshold value adjustment.
For the 2-level FSK demodulation, it corresponds to a conventional NRZ comparator output.
6
R
VCC
—14—
CXA3179N
12)-2. 4-level Signal and Threshold Value
The demodulated signal is optimally matched to the NRZ comparator threshold value by applying AFC
(see 13) AFC). (operation point correction using a feedback loop filter)
The comparator threshold value is fixed.
The level comparator threshold value can be adjusted by varying the detector output level by changing the
damping resistance of the discriminator. (AC gain adjustment)
Level comparator threshold value 1
NRZ threshold value=Demodulated signal average voltage
Level comparator threshold value 2
AC gain adjustment
12)-3. Offset Amount and Threshold Value
Immediately after power-on when the REF capacitor is not charged with the correction voltage, if the input
frequency has an offset, some time is required to correct this offset. In addition, the times required to
obtain 2-level and 4-level data differ according to the offset amount.
a) 2-level signals
In the case of 2-level signals, correct data is obtained when the offset amount is smaller than the detector
output amplitude. This is 75 mV or less when the detector output level is 150 mVp-p which corresponds to
within ±4.8 kHz when converted to a frequency by the S curve. Thus, 2-level data is obtained without an
operation point correction time lag when the frequency offset is within ±4.8 kHz.
NRZ threshold
value offset
b) 4-level signals
In the case of 4-level signals, correct data is obtained when the offset amount is less than 1/3 of the
detector output amplitude (during ±4.8 kHz DEV). This is 25 mV or less when the detector output level is
150 mVp-p which corresponds to ±1.6 kHz or less when converted to a frequency by the S curve. Thus, 4level data is obtained without an operation point correction time lag when the frequency offset is within
±1.6 kHz
Level comparator threshold value 1
NRZ threshold
value offset
Level comparator threshold value 2
As shown above, 4-level signals have an allowable offset range 1/3 that of 2-level signals. When the offset
exceeds this allowable range, time is required to determine the operation point and obtain correct data
through feedback. Also, even if the offset is within the allowable range, the output pulse duty changes until
the offset is 0.
—15—
CXA3179N
13) AFC
The AFC is of the current output type which outputs the frequency deviation in the form of the current and
converts it to the voltage. The output current range is approximately ±0.4 µA for the slow mode and ±70
µA for the fast mode. The circuit to be connected with this pin should have the higher impedance.
The operating range of the AFC pin is between approximately 0.1 V to (VCC –0.2) V. Use the buffer
amplifier to expand the operating range.
AUDIO
16
BUF
COMP
LPF
19
Vref
V=it/C
1st MIX
To CXA3179N
Vin (S curve voltage)
1st OSC
7
VCO
Vref
C
RF
External parts
The Pin 7 voltage V continues to change till the Vin value reaches the Vref value. When these values are
equal, the Pin 7 output current becomes “0” and the voltage is determined by the charge and time.
Therefore, the Pin 7 voltage is undefined.
The AFC voltage varies, for example, as shown below by the VCO characteristics. The AFC voltage
follows the VCO characteristics because this voltage is independent of the slope of the S curve. In other
words, the CXA3179N operates according to the VCO characteristics when the VCO characteristics have
the linearity with respect to the voltage and the VCO characteristics can be controlled within the range
shown in the graph below.
A
B
Pin 7 voltage
(VCC–0.2)V
C
0.1V
f0
Input frequency
—16—
CXA3179N
14) Sensitivity Adjustment Method
The constants shown in the Application Circuit are for the standard external parts. However, adjustment
may be necessary depending on the conditions of use, characteristics of external parts, and the RF system
circuit and decoder connected to the IF IC, etc. Adjust the sensitivity according to the following
procedures.
a) MIX IN matching
When using a matching circuit between the RF system circuit and MIX IN of the CXA3179N, adjust the
trimmer to obtain the optimal sensitivity while monitoring the AUDIO output.
b) Local input level
The mixer circuit gain is dependent on the local signal input level to OSC IN. The input level to OSC IN
should be set as high as possible within the range of –6 to +2 dBm as shown in the graph of “Local input
level vs. Mixer gain characteristics”. However, care should be taken as raising the input level above +2
dBm will cause the sensitivity to drop.
When creating the local signal using the internal oscillator circuit, the oscillation level varies according to
the external capacitances attached to Pins 1 and 2 and the characteristics of the used crystal. Therefore,
be sure to adjust the external capacitance values attached to Pins 1 and 2 according to the crystal
characteristics.
OSC
1
2
C1
C2
VCC
C1 and C2 have the following range in the figure above.
C1 ≥ C2
C1 = C2 to C1 =5C2
As for the ratio of C1 to C2, the oscillation stabilizes as C1 approaches equality with C2.
The oscillation level decreases as the C1 and C2 values become larger, and increases as the C1 and C2
values become smaller.
Use a FET probe to confirm the local input level.
c) LPF constant
The data filter cut-off may need to be changed depending on the characteristics of the connected decoder.
Adjust the capacitance values of Pins 9 to 12 while checking the incoming sensitivity including the decoder.
If the capacitance values are too large, the detector output waveform will deviate at high data rates,
causing the sensitivity to drop. Conversely, if the capacitance values are too small, the LPF will be easily
affected by noise, causing the sensitivity to drop.
Adjust capacitance values of Pins 9 to 12 so that the capacitance value described in “8)-1. LPF Constant”
becomes smaller.
—17—
CXA3179N
d) Detector output level
The NRZ comparator and level comparator threshold values are fixed for the CXA3179N. In the case of 4level signals, the relationship between the level comparator threshold value and the detector output level
affects the sensitivity. The detector output level can be adjusted by the resistance attached to Pin 8.
Increasing the resistance value also increases the output level, and vice versa.
The Pin 8 resistance value differs according to the ceramic discriminator attached to Pin 8. When the
discriminator is changed to a different type, the resistance value must be adjusted.
Adjust the resistance value while monitoring the level comparator output waveform or the sensitivity
including the decoder.
e) AFC
The CXA3179N uses AFC to correct the IF frequency deviation. When the IF frequency deviation amount
is large, correction takes time and may lower the sensitivity. Adjust the oscillator frequency of the local
oscillator so that the center frequency of the signal input to Pin 5 (IF IN) is as close to 455 kHz as possible.
15) CXA3179N Standard Board Description
• Outline
This board contains the external parts shown in the Application Circuit in order to evaluate the
CXA3179N operation
• Features
The following CXA3179N basic operations can be checked.
1) Varying the data filter cut-off
2) Battery saving and other mode switching
3) NRZ output and level comparator output pins
4) AFC pin — Pin 7 serves as the output pin for the AFC.
• Method of use
1) Input the CXA3179N supply voltage VCC=1.4.
This IC operates with a single power supply.
2) The CXA3179N uses a 21.245 MHz crystal. Input the RF signal from the RF pin and use this IC in
the condition where IF=455 kHz.
3) The AFC pin voltage is undefined with the IC itself because the current output circuit is employed for
the AFC. For the evaluation, be sure to apply the bias to the AFC pin externally or to make the AFC
loop.
4) Set the mode switches.
• Mode switch setting
Mode switches S1, S2, S3 and S4 are provided in four locations in the board. Each basic operation can
be confirmed by switching these mode switches while referring to the board layout. See the table in “15)
Control Pins” for the mode switching.
• Device specification
See these specifications for the IC specifications. The ICs for this evaluation board are ES specification.
• Circuit diagram
The circuit diagram is the same as the Application Circuit in these Specifications.
—18—
CXA3179N
15) -1. Standard Board Layout
RF
S2
PNP
S3
GND
S4
VCC
24
13
1
12
XTAL
S1
CERAFIL
DISK
3179
EVALUATION BOARD
15) -2. Mode Switch Pattern
High
Quick charge
L
Sleep
H
IC operation
AFC operation
H
AFC off
S3
L
B.S.
AFC-OFF
L
fc : High
H
fc : Low
S1
AFC C.
S2
Slow charge
S4
Low
FIL SW
—19—
CXA3179N
15) -3. List of Standard Board Parts
Part #
Remarks
(Manufacture)
Note
R4
R7
R5
R6
R8
(RIVER)
E12 series
1/8W
6.8 P to 45 P
C2
TZ03P450FR169
(MURATA PRODUCTS)
TRIMMER CAPACITOR
15 P
22 P
100 P
1000 P
1100 P
680 P
1420 P
C5
C4
C14
C3
C11
C12
C13
C8
C9
DD100 series
temperature characteristics
type B
(MURATA PRODUCTS)
CERAMIC CAPACITOR
E12 series
(high dielectric constant type)
25 V 1 µ
(SHIN-EI TUSHIN KOGYO CO., LTD.)
25 V 10 µ
(SHIN-EI TUSHIN KOGYO CO., LTD.)
ELECTROLYTIC CAPACITOR
E6 series
L1
EL0405
(TDK Products)
E12 series
2.5 mm pitch
(Lead Pitch)
PNP
2SA1015
(TOSHIBA CORPORATION)
XTAL
NR-18BN
(NIHON DEMPA KOGYO CO., LTD.)
Value
Resistor
220
8.7 k
100 k
Capacitor
0.01 µ
1µ
C10
10 µ
C6
C7
Inductor
1.8 µH
Active Component
Crystal
21.245 MHz
—20—
CXA3179N
Ceramic Filter
CFWS455D
(MURATA PRODUCTS)
455 kHz
1.5 kΩ
DISC
CDBM455C50
(MURATA PRODUCTS)
455 kHz
S1, S2
S3, S4
ATE1D-2M3-10
(FUJISOKU CORPORATION)
ON-ON (1 poles)
RF
HRM300-25
(HIROSE ELECTRIC CO., LTD.)
SMA CONNECTOR
CERAFIL
Ceramic Discriminator
Switch
Connector
Pin
×2
×6
Mac 8 test pin ST-1-3
(Mac eight)
Mac 8 test pin LC-2-G
(Mac eight)
—21—
L=10 mm 0.8 φ
CXA3179N
Example of Representative Characteristics
Mixer input audio response and RSSI characteristics
S+N+D
0
1000
RSSI
800
RF 21.7MHz
LOCAL 21.245MHz –6dBm
Audio 1.6kHz CW
Dev. 4.8kHz
0dB = 63.1mVrms
VCC = 1.4V
T = 25°C
–20
–30
600
400
–40
200
–50
0
RSSI [mV]
Audio response [dB]
–10
S/N
–60
–120
–110
–100
–90
–80
–70
–60
Mixer input level [dBm]
–50
–40
–30
–20
Mixer I/O characteristics and 3rd intercept point
Current consumption characteristics
–20
1.3
–30
1.2
Output level [dBm]
Current consumption [mA]
1.4
1.1
1.0
fO
–40
–50
fO=21.7MHz
fLO=21.245MHz –6dBm
–60
0.9
–70
1.0
2.0
3.0
Supply voltage [V]
4.0
f1 + f2
–80
–60 –50
—22—
f1=21.725MHz
f2=21.750MHz
The I/O level is for the values read at
I/O pin with the spectrum analyzer
–40 –30 –20 –10
Mixer input level [dBm]
0
CXA3179N
Local input level vs. Mixer gain characteristics
10
Mixer gain [dB]
5
fRF 21.7MHz –60dBm
fLO 21.245MHz
0
0.01µ
1
–5
50
–20
–15
–10
–5
Local input level [dBm]
0
5
Variable cut-off characteristics of audio filter
Pin 12 voltage
L
H
0
Response [dB]
–10
–20
–30
–40
–50
–60
100
200
500
1k
2k
5k
Input frequency [Hz]
10k
Level comparator characteristics
2.0
Comparator output voltage [mV]
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
150
200
250
Comparator input voltage [mV]
—23—
300
CXA3179N
Level comparator threshold value [mV]
Level comparator threshold value control characteristics
(Output low → high switching level)
Representative example
using typical sample
300
250
210
200
150
Typical value when Pin 6 is shorted to VCC
100
0
0.5
1.0
1.5
2.0
Pin 6 current [µA]
2.5
3.0
NRZ comparator characteristics
Comparator output voltage [V]
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
160
180
200
220
240
Comparator input voltage [mV]
260
LVA characteristics
LVA comparator output voltage [V]
1.2
1.0
0.8
0.6
0.4
0.2
0
1.00
1.05
Supply voltage [V]
—24—
1.10
1.15
CXA3179N
RSSI output voltage temperature characteristics
700
600
500
400
300
: –20°C
:
0°C
: 25°C
: 50°C
: 75°C
200
100
–120
–110
–100
–90
–80
–70
–60
RF input level [dBm]
–50
–40
Detector output level and level comparator
threshold value temperature characteristics
4.8kHz Dev. detector output level
100
Detector output level and level comparator threshold value [mV]
RSSI output voltage characteristics [mV]
800
Level comparator threshold
value for positive side
50
1.6kHz Dev. detector output level
0
Level comparator threshold value for negative side
–50
:H
:L
–100
–20
0
25
50
Temperature [°C]
—25—
75
L
H
–30
–20
CXA3179N
AFC output current characteristics
80
0.7
FAST
0.5
SLOW
0.3
40
20
0
0
AFC OFF
–20
0.3
–40
0.5
–60
0.7
–80
447
450
455
IF input frequency [kHz]
460
463
460
463
S curve characteristics
340
320
Audio output DC voltage [mV]
300
280
260
240
220
200
180
160
140
120
100
447
450
455
IF input frequency [kHz]
—26—
Slow current [µA]
Fast current [µA]
60
CXA3179N
Package Outline
Unit : mm
24PIN SSOP(PLASTIC)
+ 0.2
1.25 – 0.1
∗7.8 ± 0.1
0.1
24
13
∗5.6 ± 0.1
7.6 ± 0.2
A
1
12
b
0.13 M
0.5 ± 0.2
(0.15)
(0.22)
0.1 ± 0.1
DETAIL B : SOLDER
b=0.22 ± 0.03
+ 0.03
0.15 – 0.01
+ 0.1
b=0.22 – 0.05
+ 0.05
0.15 – 0.02
0.65
B
DETAIL B : PALLADIUM
0° to 10°
NOTE: Dimension “∗” does not include mold protrusion.
DETAIL A
PACKAGE STRUCTURE
PACKAGE MATERIAL
EPOXY RESIN
SONY CODE
SSOP-24P-L01
LEAD TREATMENT
SOLDER/PALLADIUM
PLATING
EIAJ CODE
SSOP024-P-0056
LEAD MATERIAL
42/COPPER ALLOY
PACKAGE MASS
0.1g
JEDEC CODE
NOTE : PALLADIUM PLATING
This product uses S-PdPPF (Sony Spec.-Palladium Pre-Plated Lead Frame).
—27—