--1--
E95119-TE
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.
Absolute Maximum Ratings (Ta = 25C)
Supply voltage
V
CC
5
V
Operating temperature
Topr
35 to +85
C
Storage temperature
Tstg
65 to +150
C
Allowable power dissipation
P
D
500
mW
Operating Conditions
Supply voltage
V
CC
2.7 to 3.6
V
Description
The CXA1742Q is an analog cellular(AMPS) FM IF
IC which include an IF filter.
Features
Include a ceramic filter function, which is normally
mounted externally.
Quadrature detection discriminator function.
This IC has almost all IF functions and is ideal for
reduction in set size because of few external parts
required.
Channel filter conforming to the AMPS standard.
Wide operating voltage range (2.7 V to 3.6 V) and
low current consumption (Icc=10 mA (typ.) when
Vcc= 3 V).
Wide range and excellent temperature
characteristics for the RSSI (receiving signal
strength indicator).
Applications
Ideally suited for cellular phones, particularly hand-
held sets.
Structure
Bipolar silicon monolithic IC
IF Amplifier for Analog Cellular Communications
40 pin QFP (Plastic)
CXA1742Q
For the availability of this product, please contact the sales office.
--2--
CXA1742Q
Block Diagram and Pin Configuration
(Top View)
Note) Pins 21 and 25 are connected via the IC internal wiring.
Pins 12, 21 and Pins 25, 34 are connected via IC internal resistors.
When designing a PCB, ensure that all GND pins of IC are connected to the GND on PCB with its
connection wiring distance minimized.
1
2
3
4
5
6
7
8
9
10
11
19
18
17
16
15
14
13
12
20
31
32
33
34
35
36
37
38
39
40
23
22
21
24
25
26
27
30
28
29
XTALIN
XTALOUT
AGCPS
VREF
RSSIPS
T2
RSDETPS
T1
GND2
V
CC
2
T3
MIXADJ2
MIXPS
GND
V
CC
IFPS
IFIN
GND
MIXIN
MIXADJ1
T4
T5
V
CC
1
GND1
T6
FADJ1
SGND
BPFPS1
FADJ2
BPFPS2
BIAS
LIM
DET
RSSI
AGC
BPF1
BPF0
1/
2
OSC
PSN
PSN
RF AMP
MIXER
SW
NC
BPFO
AUDIO
RSSI
GADJ(RSSI)
IF2
LIMPS
LIMIN
--3--
CXA1742Q
1
SW
2
NC
3
BPFO
1.83V
4
LIMIN
Open
5
Base
6
AUDIO
1.85V
50k
GND
31
34
1
VREF
50k
20A
11
12
1k
6
33
34
147
3
B.P.F
N.F.B Network
Used at the GND potential.
Not intemally connected.
BPF output.
Connect to Pins 4,5.
Input of BPF output.
The DC bias is applied
from pin3 when the output
of BPF is connected to
them.
Outputs an AUDIO signal
which is FM-detected.
Pin No.
Symbol
Pin voltage
I/O
Equivalent circuit
Description
DC
AC
resistance
LIM
RSSI
4
5
147
--4--
CXA1742Q
7
RSSI
1.1 V
8
GADJ
0.2 V
9
IF2
1.07 V
10
LIMPS
1.82 V
11
12
147
7
11
12
10
RSSI output. Outputs a
DC voltage in accordance
with the signal input to the
RF amplifier.
Adjusts the RSSI amplifier
gain.
Limiter operation monitor.
Not used normally.
Connects a limiter
integrating capacitor.
Pin No.
Symbol
Pin voltage
I/O
Equivalent circuit
Description
DC
AC
resistance
147
7
8
147
147
11
12
9
--5--
CXA1742Q
11
V
CC
2
3.0 V
12
GND2
0 V
13
T1
14
RSDETPS 1.35 V
15
T2
16
RSSIPS
1.83 V
17
VREF
1.25 V
33
34
17
reference voltage
used in the
internal circuit
Power supply. Supplies
current to the LIM, DET,
and RSSI circuits.
Ground.
IC operation check.
Connects an RSSI detector
integrating capacitor.
IC operation check.
Connects an RSSI
integrating capacitor.
Monitor for the reference
voltage used in the internal
circuit.
When connected to an
external capacitor, this pin
also functions to lower the
reference voltage dynamic
impedance.
Pin No.
Symbol
Pin voltage
I/O
Equivalent circuit
Description
DC
AC
resistance
11
12
147
14
11
12
16
--6--
CXA1742Q
18
AGCPS 0.233 V
19
XTALOUT
20
XTALIN
2.96 V
21
GND
0 V
22
IFIN
1.25 V
23
IFPS
1.25 V
24
V
CC
3.0 V
25
GND
0 V
Connects an AGC
integrating capacitor.
Connect a crystal oscillator
to form a Colpitts-type
oscillator circuit.
When an external
oscillator is used, its signal
must be connected to Pin
20.
Ground.
RF amplifier input. The
relationship between IFIN
(Pin 22) and IFPS (Pin 23)
is designed so that the IC
internal stray capacitance
is small.
Therefore, if Pins 22 and
23 are used for balance
input, the common-mode
rejection deteriorates.
Power supply.
Supplies current to the RF
AMP, MIXER, OSC, and
1/2 DIVIDER circuits.
Ground.
Pin No.
Symbol
Pin voltage
I/O
Equivalent circuit
Description
DC
AC
resistance
24
21
10k
19
15p
25
20
147
10k
33
15
34
VREF
18
24
25
21
VREF
23
22
1.5k
1.5k
--7--
CXA1742Q
26
MIXIN
1.3 V
27
MIXPS
1.3 V
28
MIX ADJ2 0.143 V
29
MIX ADJ1 0.143 V
30
T3
31
T4
32
T5
33
V
CC
1
3.0 V
34
GND1
0 V
35
T6
36
FADJ1
2.29 V
37
FADJ2
1.55 V
RF AMP output monitor.
Connected to the MIXER
input in the IC.
Balance adjustment for
mixers 1 and 2.
IC operational check.
Power supply.
Supplies current to the PSN,
BPF, and BIAS circuits.
Ground.
IC operational check.
When the resistance value
of an external resistor
connected between Pins
36 and 37 is varied, the
center frequency of the
BPF in the IC changes
accordingly.
Pin No.
Symbol
Pin voltage
I/O
Equivalent circuit
Description
DC
AC
resistance
660
28 29
4k
4k
4k
4k
660
MIXER
27
26
RF AMP
37
36
147
147
--8--
CXA1742Q
38
SGND
1.83 V
39
BPFPS1
1.17 V
40
BPFPS2
1.2 V
Monitor for the pseud-
ground voltage used in the
internal circuits.
When connected to an
external capacitor, this pin
also functions to lower the
reference voltage dynamic
impedance.
Monitor for the reference
voltage used by the BPF.
When connected to an
external capacitor, these
pins also function to lower
the reference voltage
dynamic impedance.
Pin No.
Symbol
Pin voltage
I/O
Equivalent circuit
Description
DC
AC
resistance
33
34
39
40
reference voltage
used for B.P.F
33
34
38
B.P.F signal
reference voltage
--9--
CXA1742Q
Item
Symbol
Conditions
Min.
Typ.
Max.
Unit
Current consumption - 1
Current consumption - 2
Current consumption - 3
Pin current
Pin 1 - Low
Pin current
Pin 1 - High
Pin current
Pin 19
Pin voltage - Pin 17
Pin voltage - Pin 38
Pin voltage - Pin 39
Pin voltage - Pin 40
OSC output swing
Pin 19
BPF output voltage - 1
BPF output voltage - 2
IF1 output voltage
Mixer image rejection
level
BPF 6 dB bandwidth
BPF 40 dB bandwidth
BPF extraband
attenuation
FM detection level
AM rejection ratio
I
CC-11
I
CC-24
I
CC-33
I
IL
I
IH
I
19
V
17
V
38
V
39
V
40
V
OSC
V
TG1
V
TG2
V
TIF
V
IMAG
BW
6dB
BW
40dB
ATT
40K
FM
DET
AMR
fin = 45 MHz, 30 dBm
Pin 11
fin = 45 MHz, 30 dBm
Pin 24
fin = 45 MHz, 30 dBm
Pin 33
0 V
3 V
Crystal osc. 89.88 MHz
Crystal osc. 89.88 MHz
fin = 45 MHz, 50 dBm
fin = 45 MHz, 20 dBm
fin = 45 MHz, 20 dBm
fin = 44.88 MHz, 30 dBm
Vin = 50 dBm, Swept with fin = 45 MHz
regarded as the center
Vin = 50 dBm, Swept with fin = 45 MHz
regarded as the center
fo 40 kHz
fin = 45 MHz, 30 dBm, fmod=1 kHz, Dev.
= 8 kHz, used LPF 20 kHz
fin = 45 MHz, 30 dBm, fmod = 1 kHz,
Mod = 80% used LPF 20 kHz
0.8
1.1
1.5
mA
2
2.8
3.7
mA
3.6
5.1
6.7
mA
14
10
7
A
15
22
30
A
0.4
0.6
mA
1.2
1.25
1.3
V
1.7
1.83
1.95
V
1.05
1.17
1.3
V
1.07
1.2
1.33
V
70
93
130
mV
rms
90
152
220
mV
rms
200
260
mV
rms
70
100
130
mV
rms
30
100
mV
rms
29
32
35
kHz
47
kHz
56
dB
130
166
200
mV
rms
23
30
dB
Electrical Characteristics
0dBm = 50
, 1mW
V
CC
= 3V, Ta = 25C
F
OSC
= 89.88 MHz
AMPS mode (Pin 1=Low)
--10--
CXA1742Q
Item
Symbol
Conditions
Min.
Typ.
Max.
Unit
Audio output distortion
RSSI output voltage - 11
RSSI output voltage - 12
RSSI output voltage - 13
Equivalent input
resistance Pin 22
Equivalent input
capacitance Pin 22
BPFfo temperature
characteristics
AMPS mode
THD
RSSI
11
RSSI
12
RSSI
13
R
IN
C
IN
fin = 45 MHz, 30 dBm, fmod = 1 kHz,
Dev. = 8 kHz, used LPF 20 kHz
No input
fin = 45 MHz, 60 dBm
fin = 45 MHz, 20 dBm
f = 45 MHz
f = 45 MHz
Ta = 30 to + 70C
3.2
5.5
%
1
1.1
1.25
V
1.65
1.88
2.1
V
2.4
2.62
2.8
V
1.4
k
4.7
pF
1.5
kHz
Others
--11--
CXA1742Q
Measurement Circuit
56K
VR10K
104
104
104
23
1
2
3
4
5
6
7
8
9
10
11
19
18
17
16
15
14
13
12
20
22
21
24
25
26
27
30
31
32
33
34
35
36
37
38
39
40
28
29
BIAS
LIM
DET
RSSI
AGC
BPF1
BPF0
1/2
OSC
PSN
PSN
RF AMP
MIXER
Vcc
3V
7
104
47
100
10
S6
S5
103
101
104
6
10p
102
6p
89.88MHz
0.47
102
104
223
S4
104
S3
1k
104
103
S2
1k
47k
102
220k
S1
104
1
2
3
4
5
500
1.5
--12--
CXA1742Q
Application Circuit
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.
Note) Use a 0.1F capacitor for Pin 14 decoupling.
The IC malfunctions at a capacitance of 0.047F or lower.
The oscillator circuit must be changed according to the crystal characteristics.
When designing PCB pattern, make PCB pattern so that Pins 3, 4, and 5 are connected correlatively.
23
1
2
3
4
5
6
7
8
9
10
11
19
18
17
16
15
14
13
12
20
22
21
24
25
26
27
30
31
32
33
34
35
36
37
38
39
40
28
29
BIAS
LIM
DET
RSSI
AGC
BPF1
BPF0
1/2
OSC
PSN
PSN
RF AMP
MIXER
10p
89.88MHz
0.47
6p
AUDIO
OUT
RSSI
OUT
82p
47k
220k
94k
0.1
0.1
Vcc
0.1
0.1
0.1
0.1
100p
45MHz
IN
Vcc
0.1
0.1
1.5
0.1
Vcc
20k
51k
2.2
2.2
2.2
Vcc
Oscillator circuit
--13--
CXA1742Q
Description of Operation
A 45 MHz IF signal is input to Pin 22. This input signal is amplified at the RF AMP and then mixed with the
local oscillation signals from the oscillator at the mixer to change the signal frequency to 60 kHz. When a
crystal or the other resonator circuit is connected to Pins 19 and 20, the oscillator can be self-executed by
composing a Colpitts-type oscillation circuit. It can be also used with an external local oscillation signal applied
to Pin 20.
The internal BPF eliminates any interference from the converted 60 kHz signal, which is then output to Pin 3.
The resulting signal is fed to Pins 4 and 5 to connect to the limiter and RSSI circuits.
The limiter eliminates an amplitude component from the signal. The resulting signal is then detected at the
quadrature FM detector circuit, and Pin 6 outputs an audio signal.
The RSSI circuit detects the RF AMP input signal voltage and generates from Pin 7 the DC voltage where
the detected voltage value is logarithmically compressed.
The resulting signal is fed to Pins 4 and 5 to connect to the limiter and RSSI circuits.
XTALIN
23
1
2
3
4
5
6
7
8
9
10
11
19
18
17
16
15
14
13
12
20
22
21
24
25
26
27
30
31
32
33
34
35
36
37
38
39
40
28
29
BIAS
LIM
DET
RSSI
AGC
BPF1
BPF0
1/2
OSC
PSN
PSN
RF AMP
MIXER
XTALOUT
IFIN
45MHz
IN
RSSI
OUT
AUDIO
OUT
Signal Flow
AUDIO
output
RSSI
output
Crystal
Oscillator
Circuit
--14--
CXA1742Q
1) Power supply
Power supply pins (Pins 11, 24, and 33) must be decoupled with the shortest distance.
2) Oscillator
The figures below show how to use the CXA1742Q oscillator.
19
20
V
CC
V
CC
102
SG
C
L
19
20
V
CC
Crystal
C
2
C
1
L
V
CC
(a) Inputting a local oscillation signal from an external
circuit.
The circuit current varies with the externally fed
signal amplitude.
The reason is that the AGC circuit, which works to
maintain the oscillation amplitude constant when a
Colpitts-type oscillator circuit is formed, also
operates when an external local oscillation signal
is input. Tune the L and C to the Pin 20 input
signal frequency or the needed frequency.
The tuning point is decided at the minimum of the
Pin 19 current.
Do not decide the point when the probe is
connected to Pin 19 because the tuned frequency
is deviated by the stray capacitor of the probe.
(b) Configuring a Colpitts-type oscillator circuit.
The C1, C2, and L must be changed according to
the crystal characteristics.
The oscillation Tr in the IC is internally subjected to
AGC so that the oscillation level at Pin 19 is not
likely to be affected by temperature or supply
voltage fluctuations.
3) Mixers
Since the BPF in the IC has an fo value as low as 60 kHz, the IC employs an image rejection type of mixer
having an enhanced interference elimination capability. Therefore, the two internal mixers must be
accurately adjusted so that their gains are equal. Normally, an adequate degree of image rejection is
provided without using Pins 28 and 29. However, when they are used for adjustment purposes, an
increased degree of image rejection will result.
28
29
500
--15--
CXA1742Q
4) BPF
The passband frequency of the built-in filter should be adjusted.
For adjustment method, adjust skirt characteristics of band-pass filter to be symmetric with respect to the
center frequency. Or observe the AUDIO output at Pin 7 and adjust the variable resistor between Pins 36
and 37 so as to minimize the AUDIO output distortion.
5) RSSI (receiving signal strength indicator)
RSSI detects the input signal level.
The IC generates a DC voltage output, which is nearly proportional to the logarithmic value of RF input
level. The output level can be varied by adjusting GADJ (Pin 8) resistance value. Adjust the resistance
value so that saturation does not occur when the input level is high.
37
36
V
0
dBm
Input level
V
CC
(approx. 0.5V)
Adjust for this curve.
R
SSI
7
8
RSSI
--16--
CXA1742Q
Notes on Operation
1. This IC must be handled with care because it is extremely susceptible to electrostatic surges. Particularly,
IFIN (Pin 22) is easily damaged by electrostatic surges.
2. When the 0.1F capacitor connected to Pin 14 has a capacitance of 0.047F or less, the IC malfunctions.
Be sure that the employed capacitor has an excellent temperature characteristics.
3. When the capacitance value of the 0.1F capacitor connected to Pin 38 is decreased, the IC characteristics
begin to slightly deteriorate. Further, a capacitance value increase would not improve the IC characteristics
accordingly.
4. When the capacitance value of the 0.1F capacitor connected to Pin 40 is decreased, the IC characteristics
slightly deteriorate.
5. Vcc1 (Pin 33) supplies the power to the reference bias voltage generator circuit which is necessary for IC
operations. If the same V
CC
power supply is not provided for Vcc voltages to be applied to Pins 11, 19, 24,
and 33, ensure that the Pin 33 Vcc rises first.
6. Be sure that nothing is connected to Pins 13, 15, 30, 31, 32, and 35.
7. Resistance between Pins 36 and 37
The signal of 45 MHz, 50 dBm is input from Pin 22 (IFIN) and the level of Pin 3 (BPFOUT) is read. After
that when this frequency is varied to +18 kHz and 18 kHz respectively, resistance value between Pins 36
and 37 is varied to be the same attenuation level.
8. Inductance between Pins 26 and 27
Adjustment must be made so that a 45 MHz parallel resonance circuit is formed by the inductor between
Pins 26 and 27 and the IC stray capacitor. This adjustment assures that an increased mixer conversion
gain is provided at a low input signal level.
Once the optimum value is obtained upon PCB conductive pattern determination, readjustment is
unnecessary after sample changes.
9. Pin 19 resonance circuit
Tune this circuit to the crystal oscillation frequency for normal use, tune to the external SG signal frequency
when a signal is input from the external SG. Once the optimum value is obtained upon PCB conductive
pattern determination, readjustment is unnecessary after sample changes.
--17--
CXA1742Q
Example of Representative Characteristics
The following characteristic curves are measured after IC adjustment. If the IC is not properly adjusted, the
resulting characteristics are not close to the representative characteristics presented below. When making
measurements, observe precautions 7, 8, and 9 under "Notes on Operation".
S
40
35
30
25
20
15
10
5
0
120
100
80
60
40
20
(dB)
SINAD
Input level
(dBm)
(dB)
0
10
20
30
40
50
60
Response
140
120
100
80
60
--40
20
0
(dBm)
D
N
Input level
CXA1742Q.SINAD AMPS
CXA1742Q. AMPS
f=45MHz
Dev. 8kHz
Audio 1kHz
Cmessage weighting
Ta=25C
V
CC
=3V
f=45MHz
Dev. 8kHz
Audio 1kHz
Cmessage weighting
Ta=25C
V
CC
=3V
70
60
50
40
30
20
10
0
10
(dB)
80
60
40
20
0
20
40
60
80
(kHz)
80
70
60
50
40
30
20
60
40
20
0
20
40
60
80
(kHz)
(dB)
V
CC
=3 V
Ta=25C
D/U
D/U
45MHz
f
44.88MHz
f
Selectivity characteristics
Image rejection characteristics
V
CC
=3V
Ta=25C
12dB SINAD=96.1dBm
(%)
7
6
5
4
3
2
15
10
5
0
5
10
15
V
CC
=2.7V
Ta=25C
Distortion
5
4
3
2
1
0
0
2
4
6
8
10
12
14
16
(%)
V
CC
=2.7V
Ta=25C
(kHz)
Distortion
Deviation
45MHz
f
(kHz)
Detuning characteristics
Modulation characteristics
--18--
CXA1742Q
Band-pass filter characteristics
The response characteristics of the band-pass filter (total value of BPF0 and BPF1) are shown below.
Supply voltage Vcc = 3 V, operating temperature Ta = 25C
0
100
60
80
40
20
0
20
40
60
80
AGC
operating range
IF input
B
P
F
out
put
(dBm)
(dBV)
V
CC
=3 V
IN PUT:pin 22
f=45MHz
MEASUREMENT:pin 3
I/O characteristics
70C
25C
30C
(dB)
0
20
40
60
80
20
40
60
80
100
(kHz)
GAIN
G.DELAY
125
0
(s)
(dB)
10
0
10
20
30
40
40
50
60
70
80
250
125
0
(s)
(kHz)
GAIN
G.DELAY
Frequency
Frequency
BPF characteristics-1
BPF characteristics-2
(v)
3
2.5
2
1.5
1
0.5
100
50
0
Input voltage
(dBm)
R
SSI
vo
lt
age
V
CC
=3 V
RSSI characteristics
75C
25C
30C
(dB)
0
4
8
12
16
0
10
20
(kHz)
Responce
Frequency
Audio output Frequency characteristics
V
CC
=3V, Ta=25C
INPUT
f=45MHz, 50dBm
Dev=8kHz
SONY CODE
EIAJ CODE
JEDEC CODE
PACKAGE MATERIAL
LEAD TREATMENT
LEAD MATERIAL
PACKAGE WEIGHT
EPOXY RESIN
SOLDER / PALLADIUM
COPPER / 42 ALLOY
PACKAGE STRUCTURE
PLATING
0.2g
QFP-40P-L01
QFP040-P-0707
40PIN QFP (PLASTIC)
9.0 0.4
+ 0.4
0.3 0.1
0.65
1
10
11
20
21
30
31
40
1.5 0.15
+ 0.35
0.127 0.05
+ 0.1
(8.0)
A
A
DETAIL
0.1 0.1
+ 0.15
+ 0.15
7.0 0.1
0.5
0.2
0.1
M
0.12
Package Outline Unit : mm
CXA1742Q
--19--
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