M-ary FSK Demodulating Comparator
Description
The CXA1994AM/BM is a comparator which allows
the M-ary (4-level) FSK data to be demodulated in
combination with an FM IF amplifier for pagers.
Features
Low power consumption
70A (at V
CC
= 1.4V, including the current on
battery saving control pin)
Low voltage operation
V
CC
= 1.0 to 4.0V
Applications
M-ary FSK pagers
Function
Window comparator for MSB detection
Battery saving control pin
Threshold level adjustment pin
Absolute Maximum Ratings (Ta = 25C)
Supply voltage
V
CC
7.0
V
Operating temperature
Topr
20 to +75
C
Storage temperature
Tstg
65 to +150
C
Operating Conditions
Supply voltage
V
CC
1.0 to 4.0
V
1
E96428A8Y
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.
CXA1994AM/BM
8 pin SOP (Plastic)
Block Diagram
B.S.
GND
NC
DATA OUT
V
CC
DATA IN
REF
TH CONT
2
3
4
5
6
7
8
1
For the availability of this product, please contact the sales office.
2
CXA1994AM/BM
Pin Description
Pin
No.
Symbol
Pin
voltage
Equivalent circuit
Description
1
V
CC
1.5V
Vcc.
2
TH CONT
--
Adjusts the threshold level for
comparator.
3
DATA IN
0.2V
Signal input.
Connected to the COMP IN pin of
the CXA1484A.
4
REF
0.2V
Reference input.
Connected to the SENSE pin of the
CXA1484A.
5
DATA OUT
--
Comparator output.
8
B.S.
--
Battery saving control.
6
NC
--
7
GND
0
Ground.
V
CC
GND
2
V
CC
GND
3
4
GND
5
V
CC
GND
8
3
CXA1994AM/BM
A
A
mV
mV
V
V
V
Electrical Characteristics
(V
CC
= 1.4V, Ta = 25C)
Item
Symbol
Condition
Min.
Typ.
Max.
Unit
Current consumption
Current consumption
Comparator input voltage high level
Comparator input voltage low level
Comparator output saturation voltage
Logic input voltage high level
Logic input voltage low level
I
CC
I
CCS
V
COMPH
V
COMPL
Vsat
V
THH
V
THL
V
REF
as a reference
V
REF
as a reference
0.9
70
50
50
100
6
0.4
0.35
Pin Description
1. V
CC
Power supply pin of 1V or more
2. TH CONT
This pin adjusts the threshold level and the default is approximately 50mV from the
reference voltage. The threshold level can be set lower by inserting a resistor between V
CC
and this pin. (The level cannot be set higher.)
3. DATA IN
The signal after passing through the data filter of the IF IC (CXA1484A) is input.
4. REF
Connects to the reference voltage pin of the IF IC. (Pin 15 of the CXA1484A)
5. DATA OUT
Comparator output.
6. NC
Not connected.
7. GND
Ground.
8. B.S.
Battery saving control pin. Battery saving state for low; normal operation for high.
4
CXA1994AM/BM
Electrical Characteristics Measurement Circuit
CXA1994AM/BM
DATA OUT
REF [from REF (0.2V) IF of IC]
5.1k
0.01
1
V
CC
1V to 4V
DATA IN [from DATA (DC 0.2V) of IF IC]
B.S. control
2
3
4
5
6
7
8
1
The comparator level can be set lower by inserting a resistor between Pin 1 (V
CC
) and Pin 2.
5
CXA1994AM/BM
R
E
G
I
F
L
I
M
O
S
C
R
4
7
5
k
B
S
S
1
A
S
L
V
A
O
U
T
R
E
G
O
U
T
N
R
Z
O
U
T
D
A
T
A
O
U
T
C
2
1
0
p
t
o
1
2
0
p
1
.
8
L
1
C
3
0
.
0
1
R
2
4
7
k
P
N
P
C
8
1
0
C
1
6
0
.
1
S
E
N
S
E
R
3
2
2
k
R
5
4
7
k
C
1
0
2
2
0
0
P
R
7
4
3
k
R
8
4
3
k
R
1
1
4
3
k
C
1
3
0
.
0
1
R
1
4
4
7
k
C
X
A
1
9
9
4
A
M
/
B
M
C
1
5
0
.
0
1
C
1
4
1
0
C
1
2
2
2
0
0
p
C
1
1
0
.
0
1
R
1
2
4
3
k
R
1
0
4
3
k
R
9
4
3
k
C
e
r
a
m
i
c
D
i
s
c
r
i
m
i
n
a
t
o
r
R
6
3
3
k
C
9
1
0
N
R
Z
C
O
M
P
O
P
A
M
P
O
P
A
M
P
C
H
A
R
G
E
Q
U
A
D
D
E
T
G
N
D
V
B
R
E
G
L
V
A
M
I
X
C
6
1
0
C
7
0
.
0
1
F
S
S
2
C
E
R
A
F
I
L
C
4
2
2
p
X
T
A
L
C
5
1
5
p
V
C
C
=
1
.
0
t
o
4
.
0
C
X
A
1
4
8
4
A
G
N
D
G
N
D
G
N
D
G
N
D
G
N
D
G
N
D
G
N
D
G
N
D
G
N
D
G
N
D
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
1
9
1
0
1
1
1
2
1
3
1
4
1
5
1
6
1
7
1
8
1
9
2
0
Application circuits shown are typical examples illustrating the operation of the devices. Sony cannot assume responsibility fo
r
any problems arising out of the use of these circuits or for any infringement of third party patent and other right due to same
.
Application Circuit
6
CXA1994AM/BM
Description of Operation
M-ary (M = 2- or 4-level) FSK emodulation system
Polarity discrimination output and MSB comparator output are used to demodulate the 4-level waveform shown
below.
4-level FSK demodulating waveform
01
00
10
11
01
10
00
+4.8kHz
+1.6kHz
1.6kHz
4.8kHz
0
0
1
1
0
1
0
POS
NEG
Polarity discrimination output
1
0
0
1
1
0
0
1.6kHz
4.8kHz
MSB comparator output
The 4-level FSK demodulating data is divided into a polarity discrimination output and a MSB comparator
output shown above. Here, the polarity discrimination output corresponds to a conventional NRZ comparator
output. The MSB comparator output is made comparing to the optional level setting between MSB and LSB
levels as reference.
For the 2-level FSK demodulation, it corresponds to a conventional NRZ comparator output.
Take care that the polarity of NRZ output is inverted in CXA1484A.
7
CXA1994AM/BM
Example of Representative Characteristics
Threshold level temperature characteristics
Temperature [C]
T
h
r
e
s
h
o
l
d
l
e
v
e
l
[
m
V
]
Threshold level change
L H threshold level
H L threshold level
H L threshold level
L H threshold level
Resistance between Pins 1 and 2 [k
]
T
h
r
e
s
h
o
l
d
l
e
v
e
l
[
m
V
]
50
50
0
40
30
20
10
40
30
20
10
V
CC
= 1.4V
40
30
10
20
V
CC
= 1.4V
80
60
40
20
0
40
20
60
80
20
0
40
20
60
80
H L threshold level
L H threshold level
L H threshold level
H L threshold level
8
CXA1994AM/BM
Package Outline Unit : mm
PACKAGE STRUCTURE
PACKAGE MATERIAL
LEAD TREATMENT
LEAD MATERIAL
PACKAGE MASS
EPOXY RESIN
SOLDER/PALLADIUM
42/COPPER ALLOY
0.1g
SOP-8P-L03
SOP008-P-0225
8PIN SOP (PLASTIC)
SONY CODE
EIAJ CODE
JEDEC CODE
0 to 10
0.1 0.1
+ 0.15
0
.
5
0
.
2
DETAILA
8
5
1
4
4
.
4
0
.
1
+
0
.
3
1.27
1.25 0.15
+ 0.4
6
.
4
0
.
4
A
5.0 0.1
+ 0.4
0.10
PLATING
M
0.24
b
B
(
0
.
1
5
)
0
.
1
5
0
.
0
5
(0.4)
b = 0.4 0.05
DETAIL B : SOLDER
0
.
1
5
0
.
0
1
b = 0.4 0.03
DETAIL B : PALLADIUM
+
0
.
0
3
+ 0.1
+
0
.
1
CXA1994AM
CXA1994BM
SONY CODE
EIAJ CODE
JEDEC CODE
PACKAGE STRUCTURE
PACKAGE MATERIAL
LEAD TREATMENT
LEAD MATERIAL
PACKAGE WEIGHT
EPOXY RESIN
SOLDER PLATING
COPPER / 42 ALLOY
8PIN SOP (PLASTIC) 300mil
6.1
+ 0.4
0.1
5
.
3
+
0
.
3
0
.
1
1.85
+ 0.4
0.15
0.1
+ 0.2
0.05
0.2
+ 0.1
0.05
0.45 0.1
1.27
4
1
7
.
9
0
.
4
6
.
9
0
.
5
0
.
2
0.15
0.12 M
0.1g
SOP-8P-L01
SOP008-P-0300-A
8
5
NOTE : PALLADIUM PLATING
This product uses S-PdPPF (Sony Spec.-Palladium Pre-Plated Lead Frame).
PDF 
ZIP