MC145442DW [MOTOROLA]

Single-Chip 300-Baud Modem; 单芯片300波特率的调制解调器
MC145442DW
型号: MC145442DW
厂家: MOTOROLA    MOTOROLA
描述:

Single-Chip 300-Baud Modem
单芯片300波特率的调制解调器

调制解调器 电信集成电路 电信电路 光电二极管
文件: 总12页 (文件大小:227K)
中文:  中文翻译
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by MC145442/D  
SEMICONDUCTOR TECHNICAL DATA  
The MC145442 and MC145443 silicon–gate CMOS single–chip low–speed  
modems contain a complete frequency shift keying (FSK) modulator, demodu-  
lator, and filter. These devices are with CCITT V.21 (MC145442) and Bell 103  
(MC145443) specifications. Both devices provide full–duplex or half–duplex  
300–baud data communication over a pair of telephone lines. They also include  
a carrier detect circuit for the demodulator section and a duplexer circuit for  
direct operation on a telephone line through a simple transformer.  
P SUFFIX  
PLASTIC DIP  
CASE 738  
20  
1
MC145442 Compatible with CCITT V.21  
MC145443 Compatible with Bell 103  
Low–Band and High–Band Band–Pass Filters On–Chip  
Simplex, Half–Duplex, and Full–Duplex Operation  
Originate and Answer Mode  
Analog Loopback Configuration for Self Test  
Hybrid Network Function On–Chip  
Carrier Detect Circuit On–Chip  
Adjustable Transmit Level and CD Delay Timing  
On–Chip Crystal Oscillator (3.579 MHz)  
Single + 5 V Power Supply Operation  
Internal Mid–Supply Generator  
Power–Down Mode  
Pin Compatible with MM74HC943  
DW SUFFIX  
SOG PACKAGE  
CASE 751D  
20  
1
ORDERING INFORMATION  
MC145442P  
MC145443P  
Plastic DIP  
Plastic DIP  
MC145442DW SOG Package  
MC145443DW SOG Package  
PIN ASSIGNMENT  
DSI  
LB  
1
2
20  
19  
TLA  
V
Capable of Driving – 9 dBm into a 600 Load  
AG  
CD  
3
4
18  
17  
Exl  
CDT  
TxA  
RxD  
5
6
16  
15  
RxA1  
RxA2  
V
DD  
CDA  
7
14  
13  
12  
11  
SQT  
X
8
MODE  
out  
X
9
V
in  
SS  
FB  
10  
TxD  
REV 1  
8/95  
Motorola, Inc. 1995  
BLOCK DIAGRAM  
4
7
CDT  
CDA  
LOW–BAND  
15  
16  
BPF  
RxA2  
RxA1  
3
CARRIER  
DETECT  
CD  
+
AAF  
S/H  
5
AC AMP  
DEMOD  
RxD  
*
HIGH–BAND  
BPF  
10  
1
FB  
DSI  
SMOOTHING  
FILTER  
2
17  
18  
+
LB  
MODE  
SQT  
TxA  
ExI  
13  
MODE  
CONTROL  
14  
11  
20  
TxD  
TLA  
MODULATOR  
ANALOG  
GROUND  
19  
6
INTERNAL  
V
AG  
V
AG  
GENERATOR  
8
9
V
X
SAMPLING CLOCK: 77.82 kHz  
SAMPLING CLOCK: 19.46 kHz  
DD  
SS  
CLOCK  
DIVIDER  
out  
OSCILLATOR  
12  
X
in  
V
* Refer to the FB pin description.  
ABSOLUTE MAXIMUM RATINGS (Voltages Referenced to V  
)
SS  
This device contains circuitry to protect the  
Rating  
Symbol  
Value  
Unit  
V
inputs against damage due to high static volt-  
ages or electric fields; however, it is advised that  
normalprecautionsbetakentoavoidapplication  
of any voltage higher than maximum rated  
voltages to this high impedance circuit. For  
Supply Voltage  
V
DD  
– 0.5 to + 7.0  
DC Input Voltage  
V
in  
– 0.5 to V  
+ 0.5  
V
DD  
DC Output Voltage  
V
out  
– 0.5 to V  
+ 0.5  
V
DD  
proper operation it is recommended that V and  
in  
Clamp Diode Current, per Pin  
DC Output Current, per Pin  
Power Dissipation  
I , I  
IK OK  
± 20  
mA  
mA  
mW  
°C  
°C  
V
V
be constrained to the range V (V or  
SS in  
out  
I
± 28  
) V ).  
out  
out  
DD  
Unused inputs must always be tied to an  
P
D
500  
appropriate logic voltage level (e.g., either V  
or V ).  
DD  
SS  
Operating Temperature Range  
Storage Temperature Range  
T
A
– 40 to + 85  
T
stg  
– 65 to + 150  
RECOMMENDED OPERATING CONDITIONS  
Parameter  
Supply Voltage  
Symbol  
Min  
4.5  
0
Max  
Unit  
V
V
DD  
5.5  
DC Input or Output Voltage  
Input Rise or Fall Time  
Crystal Frequency*  
V , V  
in out  
V
DD  
V
t , t  
r f  
500  
5.0  
ns  
f
3.2  
MHz  
crystal  
* Changing the crystal frequency from 3.579 MHz will change the output frequencies. The  
change in output frequency will be proportional to the change in crystal frequency.  
MC145442MC145443  
MOTOROLA  
2
DC ELECTRICAL CHARACTERISTICS (V  
Characteristic  
= 5.0 V ± 10%, T = – 40 to + 85°C)  
DD  
A
Symbol  
Min  
– 0.8  
DD  
Typ  
Max  
Unit  
High–Level Input Voltage  
LB  
V
IH  
V
V
X , TxD, Mode, SQT  
in  
3.15  
Low–Level Input Voltage  
High–Level Output Voltage  
LB  
V
0.8  
1.1  
V
V
IL  
X , TxD, Mode, SQT  
in  
V
OH  
I
I
I
= 20 µA  
= 2 mA  
= 20 µA  
CD, RxD  
CD, RxD  
V
– 0.1  
OH  
OH  
OH  
DD  
3.7  
X
V
– 0.05  
out  
DD  
Low–Level Output Voltage  
V
OL  
V
I
I
I
= 20 µA  
= 2 mA  
= 20 µA  
CD, RxD  
CD, RxD  
0.05  
0.1  
0.4  
OL  
OL  
OL  
X
out  
Input Current  
LB, TxD, Mode, SQT  
RxA1, RxA2  
I
in  
10  
± 1.0  
± 12  
± 10  
µA  
X
in  
Quiesent Supply Current (X or f  
in  
= 3.579 MHz)  
I
7
10  
mA  
µA  
pF  
crystal  
DD  
Power–Down Supply Current  
Input Capacitance  
200  
300  
X
C
10  
10  
in  
in  
All Other Inputs  
V
Output Voltage (I = ± 10 µA)  
V
2.4  
1.1  
10  
2.5  
1.2  
20  
2.6  
1.3  
30  
V
V
AG  
O
AG  
CDA Output Voltage (I = ± 10 µA)  
V
CDA  
O
Line Driver Feedback Resistor  
R
kΩ  
f
AC ELECTRICAL CHARACTERISTICS  
(V  
DD  
= 5.0 V ± 10%, T = 40 to +85°C, Crystal Frequency = 3.579 MHz ± 0.1%; See Figure 1)  
A
Characteristic  
Min  
Typ  
Max  
Unit  
TRANSMITTER  
Power Output on TxA  
dBm  
– 13  
– 10  
– 12  
– 9  
– 11  
– 8  
R
R
= 1.2 k, R  
= 1.2 k, R  
= ∞  
L
L
TLA  
TLA  
= 5.5 kΩ  
Second Harmonic Power  
= 1.2 kΩ  
56  
dBm  
R
L
RECEIVE FILTER AND HYBRID  
Hybrid Input Impedance RxA1, RxA2  
FB Output Impedance  
40  
50  
16  
kΩ  
kΩ  
Adjacent Channel Rejection  
DEMODULATOR  
48  
dBm  
Receive Carrier Amplitude  
Dynamic Range  
– 48  
36  
100  
5
– 12  
dBm  
dB  
Bit Jitter (S/N = 30 dB, Input = – 38 dBm, Bit Rate = 300 baud)  
Bit Bias  
µs  
%
Carrier Detect Threshold  
(CDA = 1.2 V or CDA grounded through a 0.1 µF capacitor)  
On to Off  
Off to On  
– 44  
– 47  
dBm  
MOTOROLA  
MC145442MC145443  
3
3.579 MHz  
8
±
0.1%  
9
Table 1. Bell 103 and CCITT V.21  
Frequency Characteristics  
Originate Mode  
Answer Mode  
R
X
TLA  
X
in  
TxD  
out  
Data  
Bell 103 (MC145443)  
Transmit  
Receive  
Transmit  
Receive  
11  
20  
17  
15  
TLA  
D
in  
V
DD  
TxA  
Space  
Mark  
1070 Hz  
1270 Hz  
2025 Hz  
2225 Hz  
2025 Hz  
2225 Hz  
1070 Hz  
1270 Hz  
RxA2  
MC145442  
MC145443  
600  
CCITT V.21 (MC145442)  
600  
16  
5
RxA1  
CDT  
4
RxD  
FB  
10  
D
out  
Space  
Mark  
1180 Hz  
980 Hz  
1850 Hz  
1650 Hz  
1850 Hz  
1850 Hz  
1180 Hz  
980 Hz  
TEST  
OUTPUT  
TEST  
INPUT  
0.1  
µF  
0.1 µF  
NOTE: Actual frequencies may be ± 5 Hz assuming 3.579545 MHz  
crystal is used.  
C
C
FB  
CDT  
MAXIMUM LEVEL OF OUT–OF–BAND ENERGY  
RELATIVE TO THE TRANSMIT CARRIER LEVEL INTO 600  
Figure 1. AC Characteristics Evaluation Circuit  
(kHz)  
256  
0
2
3.4 4  
16  
64  
PIN DESCRIPTIONS  
0
V
DD  
– 20  
– 25  
Positive Power Supply (Pin 6)  
This pin is normally tied to 5.0 V.  
15 dB/OCTAVE  
V
SS  
Negative Power Supply (Pin 12)  
– 55  
– 60  
This pin is normally tied to 0 V.  
V
Figure 2. Out–of–Band Energy  
AG  
Analog Ground (Pin 19)  
ExI  
External Input (Pin 18)  
Analog ground is internally biased to (V  
pin must be decoupled by a capacitor from V  
– V )/2. This  
SS  
AG  
DD  
to V  
and a  
SS  
The external input is the non–inverting input to the line  
driver. It is provided to combine an auxiliary audio signal or  
speech signal to the phone line using the line driver. This pin  
capacitor from V  
to V . Analog ground is the common  
AG  
DD  
bias line used in the switched capacitor filters, limiter, and  
slicer in the demodulation circuitry.  
should be connected to V  
if not used. The average level  
to maintain proper operation. (See  
AG  
must be the same as V  
AG  
TLA  
Applications Information.)  
Transmit Level Adjust (Pin 20)  
DSI  
This pin is used to adjust the transmit level. Transmit level  
adjustment range is typically from – 12 dBm to – 9 dBm. (See  
Applications Information.)  
Driver Summing Input (Pin 1)  
The driver summing input may be used to connect an ex-  
ternal signal, such as a DTMF dialer, to the phone line. A  
TxD  
series resistor, R  
A (see Applications Information and Figure 6). When ap-  
V
, is needed to define the voltage gain  
DSI  
Transmit Data (Pin 11)  
plying a signal to do DSI pin, the modulator should be  
squelched by bringing SQT (Pin 14) to a logic high level. The  
Binary information is input to the transmit data pin. Data  
entered for transmission is modulated using FSK techniques.  
A logic high input level represents a mark and a logic low rep-  
resents a space (see Table 1).  
voltage gain, A , is calculated by the formula A = – R /R  
V
V
f
DSI  
DSI  
(where R 20 k). For example, a 20 kresistor for R  
f
will provide unity gain (A = – 20 k/20 k= – 1). This pin  
V
must be left open if not used.  
TxA  
Transmit Carrier (Pin 17)  
RxD  
Receive Data (Pin 6)  
This is the output of the line driver amplifier. The transmit  
carrier is the digitally synthesized sine wave output of the  
modulator derived from a crystal oscillator reference. When a  
3.579 MHz crystal is used the frequency outputs shown in  
Table 1 apply. (See Applications Information.)  
The receive data output pin presents the digital binary data  
resulting from the demodulation of the receive carrier. If no  
carrier is present, CD high, the receive data output (RxD) is  
clamped high.  
MC145442MC145443  
MOTOROLA  
4
RxA2, RxA1  
Receive Carrier (Pins 15, 16)  
by CDT, Pin 4). This pin is held at the logic low level until the  
signal falls below the maximum threshold level for longer  
than the turn off time. (See Applications Information and  
Figure 5.)  
The receive carrier is the FSK input to the demodulator  
through the receive band–pass filter. RxA1 is the non–invert-  
ing input and RxA2 is the inverting input of the receive hybrid  
(duplexer) operational amplifier.  
CDA  
Carrier Detect Adjust (Pin 7)  
LB  
An external voltage may be applied to this pin to adjust the  
carrier detect threshold. The threshold hysteresis is internally  
fixed at 3 dB (see Applications Information).  
Analog Loopback (Pin 2)  
When a high level is applied to this pin (SQT must be low),  
the analog loopback test is enabled. The analog loopback  
test connects the TxA pin to the RxA2 pin and the RxA1 to  
analog ground. In loopback, the demodulator frequencies  
are switched to the modulation frequencies for the selected  
mode. (See Tables 1 and 2 and Figures 4c and 4d.)  
X
, X  
out in  
Crystal Oscillator (Pins 8, 9)  
A crystal reference oscillator is formed when a 3.579 MHz  
crystal is connected between these two pins. X  
(Pin 8) is  
out  
the output of the oscillator circuit, and X (Pin 9) is the input  
When LB is connected to analog ground (V ), the modu-  
in  
AG  
to the oscillator circuit. When using an external clock, apply  
lator generates an echo cancellation tone of 2100 Hz for  
MC145442 CCITT V.21 and 2225 Hz for MC145443 Bell 103  
systems. For normal operation, this pin should be at a logic  
low level (V ).  
The power–down mode is enabled when both LB and SQT  
are connected to a logic high level (see Table 2).  
the clock to the X (Pin 9) pin and leave X  
internal 10 Mresistor and internal capacitors, typically  
(Pin 8) open. An  
in out  
10 pF on X and 16 pF on X , allow the crystal to be con-  
in out  
SS  
nected without any other external components. Printed cir-  
cuit board layout should keep external stray capacitance to a  
minimum.  
Table 2. Functional Table  
FB  
MODE  
Pin 13  
SQT  
LB  
Filter Bias (Pin 10)  
Pin 14  
Pin 2  
Operating Mode  
Originate Mode  
Answer Mode  
This is the negative input to the ac amplifier. In normal op-  
eration, this pin is connected to analog ground through a  
0.1 µF bypass capacitor in order to cancel the input offset  
voltage of the limiter. It has a nominal input impedance of  
16 k. (see Figure 3).  
1
0
0
0
0
0
1
1
1
0
0
X
X
X
X
X
V
(V /2) Echo Tone  
AG DD  
1
0
Analog Loopback  
Squelch Mode  
SQT  
Transmit Squelch (Pin 14)  
V
(V /2) Squelch Mode  
AG DD  
When this input pin is at a logic high level, the modulator is  
disabled. The line driver remains active if LB is at a logic low  
level (see Table 2) .  
1
Power Down  
When both LB and SQT are connected to a logic high  
level, see Table 2, the entire chip is in a power down state  
and all circuitry except the crystal oscillator is disabled. Total  
power supply current decreases from 10 mA (Max) to 300 µA  
(Max).  
MODE  
Mode (Pin 13)  
This input selects the pair of transmit and frequencies  
used during modulation and demodulation. When a logic  
high level is placed on this input, originate (Bell) or channel 1  
(CCITT) is selected. When a low level is placed on this input,  
answer (Bell) or channel 2 (CCITT) is selected. (See  
Tables 1 and 2 and Figure 4.)  
FROM  
BAND–PASS  
FILTER  
TO  
+
CARRIER DETECT CIRCUIT  
AND DEMODULATOR  
CDT  
Carrier Detect Timing (Pin 4)  
490 k  
A capacitor on this pin to V  
carrier must be present before CD goes low (see Applica-  
tions Information for the capacitor values).  
sets the amount of time the  
SS  
16 k  
10  
FB  
0.1  
CD  
Carrier Detect Output (Pin 3)  
µ
F
This output is used to indicate when a carrier has been  
sensed by the carrier detect circuit. This output goes to a  
logic low level when a valid signal above the maximum  
threshold level (defined by CDA, Pin 7) is maintained on the  
input to the hybrid circuit longer then the response (defined  
Figure 3. ac Amplifier Circuit  
MOTOROLA  
MC145442MC145443  
5
In the answer or channel 2 mode, a logic low level is  
placed on MODE (Pin 13) and on LB (Pin 2). In this mode,  
the data follows the same path except the FSK signal is  
routed to the high–band band–pass filter and the sample–  
and–hold signal is routed through the low–band band–pass  
filter. (See Figure 4b.)  
In theanalog loopback originate or channel 1 mode, a logic  
high level is placed on MODE (Pin 13) and on LB (Pin 2).  
This mode is used for a self check of the modulator, demodu-  
lator, and low–band pass–band filter circuit. The modulator  
side is configured exactly like the originate mode above ex-  
cept the line driver output (TxA, Pin 17) is switched to the  
negative input of the hybrid op–amp. The RxA2 input pin is  
open in this mode and the non–inverting input of the hybrid  
GENERAL DESCRIPTION  
The MC145442 and MC145443 are full–duplex low–speed  
modems. They provide a 300–baud FSK signal for bidirec-  
tional data transmission over the telephone network. They  
can be operated in one of four basic configurations as deter-  
mined by the state of MODE (Pin 13) and LB (Pin 2). The  
normal (non–loopback) and self test (loopback) modes in  
both answer and originate modes will be discussed.  
For an originate or channel 1 mode, a logic high level is  
placed on MODE (Pin 13) and a logic low level is placed on  
LB (Pin 2). In this mode, transmit data is input on TxD, where  
it is converted to a FSK signal and routed through a low–  
band band–pass filter. The filtered output signal is then buff-  
ered by the Tx op–amp line driver, which is capable of driving  
– 9 dBm onto a 600 line. The receive signal is connected  
through a hybrid duplexer circuit on Pins 15 and 16, RxA2  
and RxA1. The signal then passes through the anti–aliasing  
filter, the sample–and–hold circuit, is switched into the high–  
band band–pass filter, and then switched into the ac amplifier  
circuit. The output of the ac amplifier circuit is routed to the  
demodulator circuit and demodulated. The resulting digital  
data is then output through RxD (Pin 5). The carrier detect  
circuit receives its signal from the output of the ac amplifier  
circuit and goes low when the incoming signal is detected  
(see Figure 4a).  
circuit is connected to V . The sample–and–hold output by-  
AG  
passes the filter so that the demodulator receives the modu-  
lated Tx data (see Figure 4c). This test checks all internal  
device components except the high–band band–pass filter,  
which can be checked in the answer or channel 2 mode test.  
In the analog loopback or channel 2 mode, a logic low level  
is placed on MODE (Pin 13) and a logic high level on LB  
(Pin 2). This mode is used for a self check of the modulator,  
demodulator, and high–band pass–band filter circuit. This  
configuration is exactly like the originate loopback mode  
above, except the signal is routed through the high–band  
pass–band filter (see Figure 4d).  
MC145442MC145443  
MOTOROLA  
6
15  
16  
RxA2  
RxA1  
CARRIER  
DETECT  
3
CD  
+
AC  
AMP  
LOW–BAND  
BPF  
AAF  
S/H  
5
1
DEMOD  
RxD  
DSI  
11  
HIGH–BAND  
BPF  
SMOOTHING  
FILTER  
TxD  
+
MODULATOR  
17  
18  
TxA  
Exl  
(a) Originate/Channel 1 Mode (MODE = High, LB = Low)  
15  
16  
RxA2  
RxA1  
CARRIER  
DETECT  
3
CD  
+
AC  
AMP  
LOW–BAND  
BPF  
AAF  
S/H  
5
1
DEMOD  
RxD  
DSI  
11  
HIGH–BAND  
BPF  
SMOOTHING  
FILTER  
TxD  
MODULATOR  
+
17  
18  
TxA  
Exl  
(b) Answer/Channel 2 Mode (MODE = Low, LB = Low)  
15  
16  
RxA2  
RxA1  
CARRIER  
DETECT  
3
CD  
+
AC  
AMP  
AAF  
S/H  
LOW–BAND  
BPF  
5
1
DEMOD  
RxD  
DSI  
11  
HIGH–BAND  
BPF  
SMOOTHING  
FILTER  
+
TxD  
MODULATOR  
17  
TxA  
Exl  
18  
(c) Originate/Channel 1 Mode and Analog Loopback State (MODE = High, LB = Low)  
15  
16  
RxA2  
RxA1  
CARRIER  
DETECT  
3
CD  
+
AC  
AMP  
AAF  
S/H  
LOW–BAND  
BPF  
5
1
RxD  
DSI  
DEMOD  
11  
HIGH–BAND  
BPF  
SMOOTHING  
FILTER  
MODULATOR  
+
TxD  
17  
TxA  
Exl  
18  
(d) Answer/Channel 2 Mode and Analog Loopback State (MODE = Low, LB = Low)  
Figure 4. Basic Operating Modes  
MOTOROLA  
MC145442MC145443  
7
20) to V  
(Pin 6). Table 3 shows the R  
values and the  
TLA  
APPLICATIONS INFORMATION  
DD  
corresponding power output for a 600 load. The voltage at  
CARRIER DETECT TIMING ADJUSTMENT  
TxA is twice the value of that at ring and tip because TxA  
feeds the signal through a 600 resistor R to a 600 line  
Tx  
The value of a capacitor, C  
CDT  
at CDT (Pin 4) determines  
how long a received modem signal must be present above  
the minimum threshold level before CD (Pin 3) goes low. The  
transformer (see Figure 7). When choosing resistor R  
,
TLA  
keep in mind that – 9 dBm is the maximum output level al-  
lowed from a modem onto the telephone line (in the U.S.). In  
addition, keep in mind that maximizing the power output from  
the modem optimizes the signal–to–noise ratio, improving  
accurate data transmission.  
C
capacitor also determines how long the CD pin stays  
CDT  
low after the received modem signal goes below the mini-  
mum threshold. The CD pin is used to distinguish a strong  
modem signal from random noise. The following equations  
show the relationship between t  
, the time in seconds re-  
, the time in seconds required  
CDL  
Table 3. Transmit Level Adjust  
Output Transmit Level  
quired for CD to go low; t  
for CD to go high; and C  
CDT  
Valid signal to CD response time: t  
CDH  
, the capacitor value in µF.  
(Typical into 600 )  
R
6.4 × C  
TLA  
CDL  
CDH  
CDT  
0.54 × C  
Invalid signal to CD off time:  
t
– 12 dBm  
– 11 dBm  
– 10 dBm  
– 9 dBm  
CDT  
19.8 kΩ  
9.2 kΩ  
5.5 kΩ  
Example: t  
t
6.4 × 0.1 µF 0.64 seconds  
0.54 × 0.1 µF 0.054 seconds  
CDL  
CDH  
CARRIER DETECT THRESHOLD ADJUSTMENT  
The carrier detect threshold is set by internal resistors to  
activate CD with a typical – 44 dBm (into 600 ) signal and  
deactivate CD with a typical – 47 dBm signal applied to the  
input of the hybrid circuit. The carrier detect threshold level  
can be adjusted by applying an external voltage on CDA  
(Pin 7). The following equations may be used to find the CDA  
THE LINE DRIVER  
The line driver is a power amplifier used for driving the  
telephone line. Both the inverting and noninverting input to  
the line driver are available for transmitting externally gener-  
ated tones.  
Exl (Pin 18) is the noninverting input to the line driver and  
gives a fixed gain of 2 (R = 50 k). The average signal level  
voltage required for a given threshold voltage. (V and V  
are in Vrms.)  
on  
off  
i
must be the same as V  
pin should be connected to V  
to maintain proper operation. This  
if not used.  
V
CDA  
V
CDA  
= 244 × V  
on  
= 345 × V  
off  
AG  
AG  
The driver summing input (DSI, Pin 1) may be used to con-  
nect an external signal, such as a DTMF dialer, to the phone  
line. When applying a signal to the DSI pin, the modulator  
should be squelched by bringing SQT (Pin 14) to a logic high  
level. DSI must be left open if not used.  
Example (Internally Set)  
V
V
= 4.9 mV – 44 dBm: V  
= 3.5 mV – 47 dBm: V  
= 244 × 4.9 mV = 1.2 V  
= 345 × 3.5 mV = 1.2 V  
on  
CDA  
CDA  
off  
Example (Externally Set)  
In addition, the DSI pin is the inverting side of the line driv-  
er and allows adjustable gain with a series resistor R  
(see  
DSI  
V
V
= 7.7 mV – 40 dBm: V  
= 5.4 mV – 43 dBm: V  
= 244 × 7.7 mV = 1.9 V  
= 345 × 5.4 mV = 1.9 V  
on  
CDA  
CDA  
Figure 6). The voltage gain, A , is determined by the  
V
off  
equation:  
The CDA pin has an approximate Thevenin equivalent  
voltage of 1.2 V and an output impedance of 100 k. When  
using the internal 1.2 V reference a 0.1 µF capacitor should  
R
f
A = –  
V
R
DSI  
be connected between this pin and V  
(see Figure 5).  
SS  
where R 20 kΩ.  
f
TRANSMIT LEVEL ADJUSTMENT  
Example: A resistor value of 20 kfor RDSI will provide  
unity gain.  
The power output at TxA (Pin 17) is determined by the  
value of resistor R that is connected between TLA (Pin  
A = – (20 k/20 k) = – 1  
V
TLA  
MC145442MC145443  
MOTOROLA  
8
V
DD  
ac  
AMP  
AUTO–NULLED  
COMPARATOR  
HYBRID  
16  
7
6 ms  
RETRIGGERABLE  
ONE–SHOT  
3
RxA1  
CDA  
CD  
V
ref  
V
1.2 V  
SAMPLING  
CLOCK  
THRESHOLD  
CONTROL  
CDA  
4
CDT  
C
CDA  
0.1 µF  
C
CDT  
0.1  
µF  
Figure 5. Carrier Detect Circuit  
MODULATOR  
OUTPUT  
R
= R  
0
f
R
0
DSI  
1
R
R
f
DSI  
TxA  
17  
ExI  
18  
+
R
i
V
AG  
19  
Figure 6. Line Driver Using the DSI Input  
MOTOROLA  
MC145442MC145443  
9
+ 5 V  
0.1 µF  
0.1 µF  
0.1 µF  
17  
19  
6
EIA–232–D  
DB–25  
CONNECTOR  
9
8
V
V
CC  
V
DD  
DD  
1
3
X
in  
20  
20  
1
C1+  
3.58  
MHz  
C1+  
C1–  
TLA  
C
R
DSI  
R
DSI  
18  
TLA  
DTMF  
INPUT  
C1–  
DI2  
X
out  
DSI  
TxA  
RxA2  
8
11  
15  
17  
15  
20 k  
MMBZ15VDLT1 X 3  
0.1  
µF  
10  
CD  
TxD  
RxD  
Tx2  
Rx1  
Tx1  
R
600  
DO1  
DI1  
Tx  
MC145442/3  
MC145407  
2
3
10 µF  
6
8
10  
+
16  
13  
10 k  
TIP  
RxA1  
SQT  
*
TxEN  
STBY  
10 k  
RING  
18  
10  
19  
Exl  
FB  
V
DD  
C
FB  
7
9
LB  
Rx2  
Rx3  
7
10 k  
0.1  
µF  
0.1 µF  
V
MODE  
AG  
V
4
CDT  
4
GND  
12  
CDA  
7
GND  
SS  
2
0.1  
µF  
C
0.1  
C
CDT  
CDA  
0.1 µF  
µ
F
* Line Protection Circuit  
Figure 7. Typical MC145442/MC145443 Applications Circuit  
MC145442MC145443  
MOTOROLA  
10  
PACKAGE DIMENSIONS  
P SUFFIX  
PLASTIC DIP  
CASE 738–03  
-A-  
NOTES:  
1. DIMENSIONING AND TOLERANCING PER ANSI  
Y14.5M, 1982.  
2. CONTROLLING DIMENSION: INCH.  
3. DIMENSION L TO CENTER OF LEAD WHEN  
FORMED PARALLEL.  
20  
1
11  
10  
B
4. DIMENSION B DOES NOT INCLUDE MOLD  
FLASH.  
C
L
INCHES  
MILLIMETERS  
DIM  
A
B
C
D
E
F
G
J
K
L
M
N
MIN  
MAX  
1.070  
0.260  
0.180  
0.022  
MIN  
25.66  
6.10  
3.81  
0.39  
1.27 BSC  
1.27  
2.54 BSC  
0.21  
MAX  
27.17  
6.60  
4.57  
0.55  
1.010  
0.240  
0.150  
0.015  
0.050 BSC  
0.050  
0.100 BSC  
0.008  
0.110  
-T-  
SEATING  
PLANE  
K
M
0.070  
1.77  
E
N
0.015  
0.140  
0.38  
3.55  
G
F
J 20 PL  
2.80  
0.300 BSC  
15  
0.040  
7.62 BSC  
15  
0.51 1.01  
D 20 PL  
M
M
0.25 (0.010)  
T
B
0°  
°
0°  
°
0.020  
M
M
0.25 (0.010)  
T
A
DW SUFFIX  
SOG PACKAGE  
CASE 751D–04  
NOTES:  
–A–  
1. DIMENSIONING AND TOLERANCING PER  
ANSI Y14.5M, 1982.  
2. CONTROLLING DIMENSION: MILLIMETER.  
3. DIMENSIONS A AND B DO NOT INCLUDE  
MOLD PROTRUSION.  
20  
11  
4. MAXIMUM MOLD PROTRUSION 0.150  
(0.006) PER SIDE.  
10X P  
–B–  
5. DIMENSION D DOES NOT INCLUDE  
DAMBAR PROTRUSION. ALLOWABLE  
DAMBAR PROTRUSION SHALL BE 0.13  
(0.005) TOTAL IN EXCESS OF D DIMENSION  
AT MAXIMUM MATERIAL CONDITION.  
M
M
0.010 (0.25)  
B
1
10  
MILLIMETERS  
INCHES  
20X D  
DIM  
A
B
C
D
MIN  
12.65  
7.40  
2.35  
0.35  
0.50  
MAX  
12.95  
7.60  
2.65  
0.49  
0.90  
MIN  
MAX  
0.510  
0.299  
0.104  
0.019  
0.035  
J
0.499  
0.292  
0.093  
0.014  
0.020  
M
S
S
0.010 (0.25)  
T
A
B
F
F
G
J
K
M
P
R
1.27 BSC  
0.050 BSC  
0.25  
0.10  
0
0.32  
0.25  
7
0.010  
0.004  
0
0.012  
0.009  
7
R X 45  
10.05  
0.25  
10.55  
0.75  
0.395  
0.010  
0.415  
0.029  
C
SEATING  
PLANE  
–T–  
M
18X G  
K
MOTOROLA  
MC145442MC145443  
11  
Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty, representationorguaranteeregarding  
the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit,  
andspecifically disclaims any and all liability, includingwithoutlimitationconsequentialorincidentaldamages. “Typical” parameters can and do vary in different  
applications. All operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. Motorola does  
not convey any license under its patent rights nor the rights of others. Motorola products are not designed, intended, or authorized for use as components in  
systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of  
the Motorola product could create a situation where personal injury or death may occur. Should Buyer purchase or use Motorola products for any such  
unintendedor unauthorized application, Buyer shall indemnify and hold Motorola and its officers, employees, subsidiaries, affiliates, and distributors harmless  
against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death  
associated with such unintended or unauthorized use, even if such claim alleges that Motorola was negligent regarding the design or manufacture of the part.  
Motorola and  
are registered trademarks of Motorola, Inc. Motorola, Inc. is an Equal Opportunity/Affirmative Action Employer.  
How to reach us:  
USA/EUROPE: Motorola Literature Distribution;  
JAPAN: Nippon Motorola Ltd.; Tatsumi–SPD–JLDC, Toshikatsu Otsuki,  
P.O. Box 20912; Phoenix, Arizona 85036. 1–800–441–2447  
6F Seibu–Butsuryu–Center, 3–14–2 Tatsumi Koto–Ku, Tokyo 135, Japan. 03–3521–8315  
MFAX: RMFAX0@email.sps.mot.com – TOUCHTONE (602) 244–6609  
INTERNET: http://Design–NET.com  
HONG KONG: Motorola Semiconductors H.K. Ltd.; 8B Tai Ping Industrial Park,  
51 Ting Kok Road, Tai Po, N.T., Hong Kong. 852–26629298  
MC145442/D  

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