E2A0014-16-X0
¡ Semiconductor
MSM7512B
Semiconductor
1200 bps Half Duplex FSK Modem – ITU-T V.23
This version:
MSM7512B
Jan. 1998
Previous version: Nov. 1996
GENERAL DESCRIPTION
The MSM7512B is useful for the ITU-T V.23 modem, for examples, low cost built-in modems,
telecontrol systems, home security systems, etc.
The family version, MSM7510 for ITU-T V.21, will be available following this device.
Oki has been mass-producing and delivering the MSM6926 and 6927 for a long time, but these
devices need two power supplies, +5 V for digital and +12 V for analog.
New generation devices, MSM7510/7512B, work with single rail +3 V to +5 V and low power
consumption.
FEATURES
• Conforms to ITU-T V.23, 1200 bps Half Duplex
• Conforms to ITU-T V.23, 75 bps transmitter
• Single Power Supply: +3 V to +5 V
• Low Power Consumption
Operating Mode:
25 mW Typ.
Power Down Mode:
0.1 mW Max.
• Line Hybrid Circuit on Chip
• Line Direct Drive Capability of Analog Output
• 3.579545 MHz Crystal Oscillator
• Digital Interface:
TTL
• Package options:
16-pin plastic DIP
(DIP16-P-300–2.54)
(Product name: MSM7512BRS)
24-pin plastic SOP
(SOP24-P-430-1.27–K)
(Product name: MSM7512BGS-K)
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Semiconductor
MSM7512B
BLOCK DIAGRAM
AI
(2)
+
–
Demodulator
FSK & ANS
Bandpass
Filter
Modulator
*R3
*R2
–
*R1
*R1
*R2
*R2
+
AOG
RD
(9)
CD
(10)
XD
(11)
RS
(12)
AO
(3)
EAI
(4)
X1
(6)
X2
(7)
CLK
(8)
V
DD
(1)
GND
(5)
TEST
(13)
OSC
CLK GEN.
CONT.
MOD2
(15)
SG GEN.
AOG
(16)
MOD1
(14)
* R1 to R3
≥
50 kW
( ) : for MSM7512BRS
2/12
Semiconductor
MSM7512B
PIN CONFIGURATION (TOP VIEW)
V
DD
1
AI 2
AO 3
EAI 4
GND 5
X1 6
X2 7
CLK 8
16-Pin Plastic DIP
16 AOG
15 MOD2
14 MOD1
13
TEST
12
RS
11 XD
10
CD
9 RD
V
DD
1
NC 2
AI 3
NC 4
AO 5
EAI 6
GND 7
X1 8
NC 9
X2 10
NC 11
CLK 12
24-Pin Plastic SOP
NC : No connect pin
24 AOG
23 NC
22 MOD2
21 NC
20 MOD1
19
TEST
18
RS
17 XD
16 NC
15
CD
14 NC
13 RD
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Semiconductor
MSM7512B
PIN DESCRIPTION
No.
RS GS-VK
1
2
3
4
5
6
7
8
9
1
3
5
6
7
8
10
12
13
Name
V
DD
AI
AO
EAI
GND
X1
X2
CLK
RD
I/O
—
I
O
I
—
I
O
O
O
+3 V to +5 V Power Supply
Analog receive signal input.
Description
Analog transmit signal output.
External analog signal input.
The signal applied to this pin is transmitted from AO via transmit output
amplifier. When not using this pin, it should be left open.
Ground, 0 V.
3.579545 MHz crystal resonator should be connected to X1 and X2.
When applying external clock 3.579545 MHz to the device, it should be
applied to X2 (not X1) via an AC-coupling capacitor of 100 pF and X1
has to be opened.
3.579545 MHz clock signal output.
Modem receive serial data output.
Digital "1" and "0" correspond to "Mark" and "Space", respectively. When
CD
(Carrier Detect) is off, RD is held at "Mark" state.
FSK Receive signal and answer tone detect.
Digital "0" and "1" represent "Detect" and "Non-detect", respectively.
Modem transmit serial data input.
Digital "1" and "0" correspond to "Mark" and "Space", respectively.
FSK signal and answer tone transmit enable.
When digital "0" is applied to
RS,
transmitting becomes enable.
Chip test input.
TEST
should be open or digital "1".
Operation mode select.
Refer to Table 1.
Analog transmit signal amplitude select.
Digital "1"
Æ
–10 dBm Typ. at AO
Digital "0"
Æ
–4 dBm Typ. at AO
10
11
12
13
14
15
16
15
17
18
19
20
22
24
CD
XD
RS
TEST
MOD1
MOD2
AOG
O
I*
I*
I*
I*
I*
I*
Note :
I* : Internally pulled-up input pin.
4/12
Semiconductor
MSM7512B
ABSOLUTE MAXIMUM RATINGS
Parameter
Power Supply Voltage
Input Voltage
Storage Temperature
Symbol
V
DD
V
IN
T
STG
Condition
Ta = 25°C,
With respect to GND
—
Rating
–0.3 to +7
–0.3 to V
DD
+ 0.3
–55 to +150
Unit
V
V
°C
RECOMMENDED OPERATING CONDITIONS
Parameter
Power Supply Voltage
Operating Temperature
Input Clock Frequency
V
DD
Bypass Capacitor
Oscillation Frequency
Frequency Deviation
Temperature Characteristics
Equivalent Series Resistance
Load Capacitance
Symbol
V
DD
T
op
f
CLK
C
VDD
—
—
—
—
—
Condition
—
—
To 3.579545 MHz
V
DD
– GND
—
+25°C ±5°C
–40°C to +85°C
—
—
Min.
+2.7
–40
–0.1
10
—
–100
–50
—
—
Typ.
—
—
—
—
3.579545
—
—
—
16
Max.
+5.5
+85
+0.1
—
—
+100
+50
50
—
Unit
V
°C
%
mF
MHz
ppm
ppm
W
pF
ELECTRICAL CHARACTERISTICS
DC Characteristics
( V
DD
= +2.7 V to +5.5 V, Top = –40°C to +85°C)
Parameter
Power Supply Current
Digital Input Voltage
Digital Input Leakage Current
Digital Output Voltage
Symbol
I
DD
I
SS
V
IL
V
IH
I
IL
I
IH
V
OL
V
OH
Condition
Operating Mode
Power Down Mode
—
—
V
I
= 0 V *
V
I
= 5 V
I
OL
= 1.6 mA
I
OH
= –0.4 mA
Min.
—
—
0
2.2
–80
–10
0
2.4
Typ.
5.0
5.0
—
—
—
—
0.2
—
Max.
10.0
20.0
0.8
V
DD
10
10
0.4
V
DD
Unit
mA
mA
V
V
mA
mA
V
V
Crystal
*
Internally pulled-up pins
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