CXA1999N
IF Amplifier for M-ary FSK Pagers
Description
The CXA1999N is a low current consumption FM
IF amplifier which employs the newest bipolar
process. It is suitable for M-ary FSK pagers.
Features
•
Low current consumption: 1.16 mA
(typ. at V
CC
= 1.4 V)
•
Low voltage operation: V
CC
= 1.1 to 4.0 V
•
Small package 20-pin SSOP
•
Second mixer and oscillator
•
Needless of IF decoupling capacitor
•
Reference power supply for operational amplifier
and comparator
•
IF input, V
CC
standard
Applications
•
M-ary FSK pagers
•
Double conversion pagers
Structure
•
Bipolar silicon monolithic IC
20 pin SSOP (Plastic)
Absolute Maximum Ratings
•
Supply voltage
•
Operating temperature
•
Storage temperature
V
CC
7.0
V
Topr –20 to +75 °C
Tstg –65 to +150 °C
375
mW
•
Allowable power dissipation P
D
Operating Condition
Supply voltage
V
CC
1
1.1 to 4.0
V
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—
E95517C8Y
Block Diagram and Pin Configuration
20
REG
OUT
REG
CONT
LVA
OUT
NRZ
OUT
CHARGE
LEVEL
COMPARATOR
L.C.
OUT
19
18
17
16
15
14
13
12
LPF OUT
11
LPF
IN
MIX
IN
GND
MIXER
REGULATOR
ALARM
NRZ
COMPARATOR
QUICK
CHARGE
—2—
IF LIM
MIX
OUT
V
CC
IF IN
B.S.
FSK
REF
QUAD
DET
LOCAL
OSCILLATOR
DET
OUT
QUAD
OSC
IN
OSC
OUT
RSSI
1
2
3
4
5
6
7
8
9
10
CXA1999N
CXA1999N
Pin Description
Pin
No.
1
Symbol
Pin voltage
Equivalent circuit
V
CC
300
15k
Description
OSC IN
1.4 V
1
2
15k
72
2
OSC OUT
0.7 V
230
GND
V
CC
1.5k
Connects the external parts of
crystal oscillator circuit.
A capacitor and crystal oscillator
are connected to these pins and
V
CC
.
3
Mixer output.
Connect a 455 kHz ceramic filter
between this pin and IF IN.
GND
3
MIX OUT
1.2 V
4
V
CC
8k 8k
1.5k
V
CC
1.5k
Power supply.
5
IF IN
1.4 V
5
IF limiter amplifier input.
GND
72
6
40k
6
B.S.
—
140k
GND
V
CC
Controls the battery saving.
Setting this pin low suspends the
operation of IC.
(Applied voltage range: –0.5 V to
+7.0 V)
7
FSK REF
0.2 V
72
7
Connects the capacitor that
determines the low cut-off
frequency for the entire system.
GND
—3—
CXA1999N
Pin
No.
Symbol
Pin voltage
Equivalent circuit
V
CC
22k
20k
Description
8
QUAD
1.4 V
8
20p
GND
V
CC
50p
Connects the phase shifter of FM
detector circuit.
9
DET OUT
0.2 V
9
72
55k
FM detector output.
GND
V
CC
7k
7k
10
RSSI
0V
10
70k
RSSI circuit output.
GND
V
CC
11
LPF IN
0.2 V
11
72
Operational amplifier input.
GND
V
CC
72
12
LPF OUT
0.2 V
12
72
GND
Level comparator and NRZ
comparator inputs. Output for
operational amplifier is
connected.
—4—
CXA1999N
Pin
No.
Symbol
Pin voltage
Equivalent circuit
Description
Level comparator, NRZ
comparator and LVA comparator
outputs. They are open
collectors.
(Applied voltage range: –0.5 V to
+7.0 V)
Controls the ON/OFF operation
of the quick-charge circuit.
Set this pin high to execute the
quick charge.
(Applied voltage range: –0.5 V to
13
72
13
15
16
L.C. OUT
NRZ OUT
LVA OUT
—
—
—
15
16
GND
20k
14
14
CHARGE
0V
100k
GND
V
CC
+7.0 V)
17
REG CONT
—
17
72
Output for internal constant-
voltage source amplifier.
Connect the base of PNP
transistor.
(Current capacity: 100 µA)
GND
V
CC
18
REG OUT
1.0 V
78k
18
1k
22k
GND
Constant-voltage source output.
Controlled to maintain 1.0 V.
19
GND
—
4.16k
4.16k
V
CC
2k
Ground
20
MIX IN
1.4 V
20
Mixer input.
GND
—5—
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