MOTOROLA MC145446

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by MC145446A/D
SEMICONDUCTOR TECHNICAL DATA
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# %" !$
The MC145446A is a silicon gate CMOS frequency shift keying (FSK)
modem intended for use with telemeter systems or remote control systems over
the telephone network. It replaces the MC145446.
This device is compatible with CCITT V.21 and contains the entire circuit that
provides a full–duplex or half–duplex 300–baud data communication over a pair
of telephone lines. This device also includes the DTMF generator/receiver and
call progress tone detector (CPTD).
The differential line driver has the capability of driving 0 dBm into a 600 Ω load
with a single 5 V power supply. The transmit level is controlled by the
programmable attenuator in 1 dB steps.
This device also includes a serial control interface and internal control and
status registers that permit a CPU to exercise the following built–in features:
•
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Single 5 V Power Supply
Compatible with CCITT V.21
DTMF Generator and Receiver for All 16 Standard Digits
Capable of Driving 0 dBm into a 600 Ω Load (VCC = 5 V)
AGC (Auto Gain Control) Amplifier for DTMF Receiver
Imprecise Call Progress Tone (400 Hz) Detector
A Transmit Attenuator Programmable in 1 dB Steps
2100 Hz Answer Tone Generator
Serial Control Interface
Analog Loopback Configuration for Self Test
Power–Down Mode, Less than 1 µA
FW SUFFIX
SOP
CASE 751M
28
1
ORDERING INFORMATION
MC145446AFW
SOP
PIN ASSIGNMENT
VCC
1
28
FTLC1
GND
2
27
RxBO
Vref
3
26
RxGC
CDA
4
25
RxA
DTMF IN
5
24
TxA1
AGC OUT
6
23
TxA2
FTLC2
7
22
DSI
FTLC3
8
21
VCC
X1
9
20
E
X2
10
19
SCK
TLA
11
18
DATA I/O
GND
12
17
TxD
VCC
13
16
RxD
R/W
14
15
SD/CD/DV
This document contains information on a new product. Specifications and information herein are subject to change without notice.
REV 1
7/96

Motorola, Inc. 1996
MOTOROLA
MC145446A
1
BLOCK DIAGRAM
AGC OUT
DTMF
IN
FLTC2
LOW–BAND
BPF
NOISE
FILTER
AGC
FLTC1
FLTC3
FREQUENCY
DETECTER
RxBO
+
RxA
HIGH–BAND
BPF
NOISE
FILTER
–
CODE
CONVERTER
(DECODER)
4
STATUS
REGISTER
TIMING
CIRCUIT
SD/CD/DV
RxGC
30 k
65 k
FSK/DTMF LOOPBACK PATH
TxD
TLA
FSK
MODULATOR
LEVEL
CONTROL
DTMF
GENERATOR
LOW–BAND
BPF
MUX
HIGH–BAND
BPF
MUX/
MIXING
CARRIER/CPT
DETECTOR
CDA
FSK
DEMODULATOR
RxD
MUX
MODE CONTROL
LOGIC
DATA
I/O
DSI
SMOOTHING
FILTER
CONTROL
SHIFT REGISTER
–1
_
+
STATUS
SHIFT REGISTER
TxA2
TxA1
R/W
E
SCK
POWER–ON
RESET
VCC
MC145446A
2
ANALOG GROUND
GENERATOR
GND
Vref
CLOCK
GENERATOR
X1
X2
MOTOROLA
ABSOLUTE MAXIMUM RATINGS (Voltages referenced to VSS)
Rating
Symbol
Value
Unit
VCC
– 0.5 to 7.0
V
DC Input Voltage
Vin
– 0.5 to VCC + 0.5
V
DC Output Voltage
Vout
– 0.5 to VCC + 0.5
V
IIK, IOK
± 20
mA
Iout
± 25
mA
DC Supply Voltage
Clamp Diode Current per Pin
DC Current per Pin
Power Dissipation
PD
500
mW
Storage Temperature Range
Tstg
– 65 to 150
°C
This device contains circuitry to protect the
inputs against damage due to high static voltages or electric fields; however, it is advised that
normal precautions be taken to avoid applications of any voltage higher than the maximum
rated voltages to this high impedance circuit.
For proper operation it is recommended that
Vin and Vout be constrained to the range VSS ≤
(Vin or Vout) ≤ VDD. Reliability of operation is
enhanced if unused inputs are tied to an
appropriate logic voltage level (e.g., either VSS
or VDD).
RECOMMENDED OPERATING CONDITIONS
Parameter
Symbol
Min
Typ
Max
Unit
VCC
4.5
5
5.5
V
DC Input Voltage
Vin
0
—
VCC
V
DC Output Voltage
Vout
0
—
VCC
V
tr
0
—
500
ns
DC Supply Voltage
Input Rise Time
Input Fall Time
Crystal Frequency
Operating Temperature Range
tf
0
—
500
ns
fosc
—
3.579545
—
MHz
TA
– 20
25
70
°C
DC ELECTRICAL CHARACTERISTICS (VCC = 5.0 V ± 10%, TA = – 20 to 70°C)
Symbol
Characteristic
Input Voltage
Output Voltage
Conditions
Min
Typ
Max
Unit
V
H Level
VIH
3.15
—
—
L Level
VIL
—
—
1.1
H Level
VOH
IOH = 20 µA
VCC – 0.1
VCC – 0.01
—
L Level
VOL
IOL = 20 µA
IOL = 2 mA
—
—
0.01
—
0.1
0.4
Vin = VCC or GND
—
± 1.0
± 10.0
µA
FSK Mode
—
8
—
mA
DCMF Receive Mode
—
10
—
Power–Down Mode 1
—
—
500
µA
Power–Down Mode 2
—
—
1
µA
Conditions
Min
Typ
Max
Unit
Crystal Frequency
3.579545 MHz
974
980
986
Hz
1174
1180
1186
Input Current TxD, E, SCK, DATA I/O, R/W
Quiescent Supply Current
Iin
ICC
ICC
Power–Down Supply Current
V
TRANSMIT CARRIER CHARACTERISTICS (VCC = 5.0 V ± 10%, TA = – 20 to 70°C)
Symbol
Characteristic
Carrier Frequency Channel 1
Carrier Frequency Channel 2
Answer Tone
Mark ‘‘1’’
f1M
Space ‘‘0’’
f1S
Mark ‘‘1’’
f2M
1644
1650
1656
Space ‘‘0’’
f2S
1844
1850
1856
2090
2100
2110
—
7
—
dBm
—
– 46
—
dBm
fans
Transmit Carrier Level
VO*
Second Harmonic Energy
V2h*
Out–of–Band Energy
VOE*
Attenuator = 0 dB
RTLA = ∞, RL = 1.2 kΩ,
VTxA1 – VTxA2
Figure 2
dBm
* VTxA1 – VTxA2, RL = 1.2 kΩ
MOTOROLA
MC145446A
3
TRANSMIT ATTENUATOR CHARACTERISTICS (VCC = 5.0 V ± 10%, TA = – 20 to 70°C)
Characteristic
Symbol
Attenuator Range
Attenuator Accuracy
1 dB – 5 dB
Min
Typ
Max
Unit
ARNG
Conditions
0
—
15
dB
AACC
– 0.5
—
0.5
dB
–1
—
1
– 1.7
—
1
6 dB – 9 dB
10 dB – 15 dB
RECEIVER CHARACTERISTICS (INCLUDES HYBRID, DEMODULATOR, AND CARRIER DETECTOR)
(VCC = 5.0 V ± 10%, TA = – 20 to 70°C)
Symbol
Characteristic
Input Impedance
RIRX
Receiver Carrier Amplitude
VIRX
Carrier Detect Threshold
OFF to ON
VCDON
ON to OFF
VCDOF
Hysterisis (VCDON – VCDOF)
Carrier Detect Timing
Conditions
Min
Typ
Max
Unit
50
—
—
kΩ
– 48
—
– 12
dBm
—
– 44
—
dBm
—
– 47
—
2
—
—
dB
CD1 = 0, CD0 = 0
—
450
—
ms
CD1 = 0, CD0 = 1
—
10
—
CD1 = 1, CD0 = 0
—
10
—
CD1 = 1, CD0 = 1
—
70
—
CD1 = 0, CD0 = 0
—
35
—
CD1 = 0, CD0 = 1
—
35
—
CD1 = 1, CD0 = 0
—
20
—
CD1 = 1, CD0 = 1
—
15
—
Min
Typ
Max
Unit
RxA Pin
CDA = 1.2 5V
fin = 1.0 kHz
HYS
OFF to ON
ON to OFF
TCDON
TCDOFF
CPTD CHARACTERISTICS (VCC = 5.0 V ± 10%, TA = – 20 to 70°C)
Symbol
Characteristic
Conditions
Bandpass Filter Center Frequency
fc
—
400
—
Hz
Bandpass Filter – 3 dB Band Width
∆ BW
—
140
—
Hz
—
– 44
—
dBm
—
– 47
—
Tone Detect Level
Tone Detect Timing
CDA = 1.25 V
fin = 400 Hz
OFF to ON
VTDON
ON to OFF
VTDOF
OFF to ON
TTDON
—
10
—
ON to OFF
TTDOF
—
25
—
Min
Typ
Max
Unit
—
2.5
—
dBm
—
3.5
—
0
—
3
dB
—
5
—
%
–1
—
1
%
—
ms
ms
DTMF TRANSMIT CHARACTERISTICS (VCC = 5.0 V ± 10%, TA = – 20 to 70°C)
Symbol
Characteristic
Tone Output Level
High Group Pre–Emphasis
DTMF Distortion
Low Group
Vfl
High Group
Vfh
PE
DIST
DTMF Frequency Variation
∆fV
Out–of–Band Energy
VOE
Setup Time
tosc
MC145446A
4
Conditions
Attenuator = 0 dB
RTLA = ∞
Crystal Frequency
3.579545 MHz
Single Tone Mode
VTxA1 – VTxA2,
RL = 1.2 kΩ
Figure 1
—
4
dB
MOTOROLA
DTMF RECEIVER CHARACTERISTICS (VCC = 5.0 V ± 10%, TA = – 20 to 70°C)
Characteristic
Symbol
Conditions
Min
Typ
Max
Unit
50
—
—
kΩ
Detect Signal Level (Each Tone)
– 48
—
0
dBm
Twist (High Group Tone/Low Group Tone
– 10
—
10
dB
Frequency Detect Band Width (Figure 4)
± 1.5% ± 2 Hz
—
—
—
—
—
± 3.5
%
CD1 = 0, CD0 = 1
—
25
—
ms
CD1 = 1, CD0 = 0
—
30
—
CD1 = 1, CD0 = 1
—
40
—
CD1 = 0, CD0 = 1
—
25
—
CD1 = 1, CD0 = 0
—
35
—
CD1 = 1, CD0 = 1
—
25
—
Typ
Max
Input Impedance
Frequency No–Detect Band Width (Figure 4)
DTMF Detect Timing
OFF to ON
ON to OFF
TCDON
TCDOFF
DEMODULATOR CHARACTERISTICS (VCC = 5.0 V ± 10%, TA = – 20 to 70°C)
Characteristic
Bit Bias
Bit Error Rate
(CCITT Line Simulation, 511–Bit Pattern)
Symbol
Conditions
Min
ID
Input Level = – 24 dBm
S/N = 4 dB
—
5
—
%
—
0.00001
—
—
BER
Unit
SWITCHING CHARACTERISTICS (VCC = 5.0 V ± 10%, TA = – 20 to 70°C)
Symbol
Timing
Diagram
Reference
No.
Min
Typ
Max
Unit
Input Pulse Width (H) E, SCK
twh
1
50
—
—
ns
Input Pulse Width (L) E, SCK
twl
2
50
—
—
ns
Clock Cycle
tc
3
100
—
—
ns
Input Rise Time
tr
4
—
—
2
µs
Input Fall Time
tf
5
—
—
2
µs
trec
6, 18
50
—
—
ns
tsu
7
50
—
—
ns
R/W↓ to DATA
9
100
—
—
ns
R/W↑ to DATA
12
50
—
—
ns
8
50
—
—
ns
E to R/W
10
50
—
—
ns
DATA to R/W
14
50
—
—
ns
R/W to DATA
15
50
—
—
ns
13
—
—
50
ns
17
—
—
50
ns
Characteristic
Recovery Time E to SCK
Setup Time
Hold Time
Read Data Delay Time
DATA to SCK
SCK to DATA
E to DATA
th
td
SCK to DATA
Enable Minimum Interval
twe
11
—
—
450
ns
Mode Switch Minimum Interval
twm
16
—
—
600
ns
MOTOROLA
MC145446A
5
CONTROL REGISTER
1
(NOTE 1)
E*
(NOTE 6)
6
SCK
1
2
7
3
4
5
2
8
9
DATA
7
3
CD1 CD0
6
7
SQ
T3
9
10
11
12
13
14
15
16
(LSB CLOCK)
5
1
CH
8
4
T2
T1
T0
A3
A2
A1
A0
M3
M2
M1
M0
10
R/W
* The enable signal corresponds to preceding data format.
STATUS REGISTER
11
E
1
2
(NOTE 7) 18
12
(NOTE 5)
4
3
SCK
5
1
2
3
13
0
2
2
1
(NOTE 3)
5
4
1 (NOTE 2)
17
DATA
1
D0
D1
D2
D3
D0
D1
D2
D0
D1
14
16
(HIGH–IMPEDANCE)
15
(NOTE 4)
R/W
NOTES:
1. The data in front of the enable signal pulse will be latched.
2. The latched data will be repeated until there is an enable pulse.
3. The detected data will be updated with the next enable pulse.
4. After the R/W pin becomes INACTIVE, the data will be lost.
5. D1 corresponds to Clock1.
6. The enable and the SCK signals need to be set at the logic low level when the R/W signal changes.
7. The SCK must be held at low level when the enable signal is at high level.
Figure 1. Serial Data Input Timing
MC145446A
6
MOTOROLA
TRANSMIT CARRIER LEVEL (dBr)
0
3.4 k 4 k
16 k
256 k
f (Hz)
0
– 25
– 15 dB/OCT.
– 55
Figure 2. Out–of–Band Energy
Von
Voff
RxA, DTMF IN
ton
toff
SD/DV/CD
Figure 3. FSK, DTMF Carrier Detect Timing
ÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉ
NO–DETECT
DETECT MINIMUM
WIDTH
– 3.5%
ÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉ
ÉÉÉÉÉÉÉÉ
NO–DETECT
+ 3.5%
– 1.5% – 2 Hz
fo
+ 1.5% + 2 Hz
Figure 4. DTMF Frequency Detect Bandwidth
MOTOROLA
MC145446A
7
PIN DESCRIPTIONS
VCC
Positive Power Supply (Pins 1, 13, 21)
TxD
Transmit Data Input (Pin 17)
The digital supply pins, which are connected to the positive
power supply (5 V).
This pin is the transmit data input. When the device is in
FSK mode, the mark frequency is generated when this pin is
at the logic high level. The space frequency is generated
when the pin is at a logic low.
GND
Ground Pins (Pins 2, 12)
RxD
Receive Data Output (Pin 16)
The ground pins are connected to the system ground.
Vref
Reference Analog Ground (Pin 3)
This pin provides the analog ground voltage, which is internally regulated to VCC/2. It should be decoupled to the GND
with 0.1 µF and 100 µF capacitors.
X1
Crystal Oscillator Output (Pin 9)
A 3.579545 MHz ± 0.1% crystal oscillator is tied to this pin
with the other end connected to X2.
X2
Crystal Oscillator Input (Pin 10)
A 3.579545 MHz ± 0.1% crystal oscillator is tied to this pin
with the other end connected to X1. X2 may also be driven
directly from an appropriate external source.
SCK
Serial Clock Input (Pin 19)
This pin is the clock input for the 16–bit control resistor and
the 4–bit status resistor. The serial data is captured into the
control register, or is shifted out of the status register on the
rising edge of SCK.
DATA I/O
Serial Data Input/Output (Pin 18)
This pin is the 16–bit control register input, which determines the operation mode, DTMF tone, transmit attenuation
(receiver gain), carrier detect time, channel, and transmit
squelch. This pin is also the four–bit status register output
which indicates the received DTMF tone (hexadecimal
codes).
E
Enable Input (Pin 20)
When the R/W pin is at logic low, high level on the E pin
makes the 16–bit control register data transparent to the
mode control logic so that the device operation is changed.
While this pin is at logic low, the control register and the
mode control logic are isolated. The E pin must NOT be held
high while the control register data is being changed.
When the R/W pin is at logic high, the rising edge of E
transfers the four–bit DTMF data from the DTMF decoder to
the status register. Then the first bit (LSB = D0) is presented
at the Data I/O pin.
R/W
Read/Write Data Switch (Pin 14)
This pin is used for controlling the I/O direction of the Data
I/O pin.
MC145446A
8
This pin is the receive data output. When the device is in
the FSK mode, a high logic level of this pin indicates that the
mark carrier frequency has been received, and a low logic
level indicates the space carrier frequency has been received.
SD/CD/DV
Carrier/Call Progress Tone Detect/DTMF Data Valid
Detect (Pin 15)
This pin works as a carrier detector in the FSK mode,
whereas it works as the call progress tone detector in the
CPTD mode and as the receive DTMF detector in the DTMF
Rx mode. The output goes to a logic low level when the input
signal reaches the minimum threshold of the detect level that
is adjusted by the CDA voltage. When this pin is logic high,
the receive data output (RxD) is clamped high to avoid the
error that may occur with the loop noise.
In DTMF Rx mode, the logic low on this pin indicates that
the valid DTMF frequencies are detected. The received tone
is decoded to four–bit data, then stored in the DTMF decoder
by the falling edge of DV.
TxA1
Non–Inverting Transmit Analog Carrier Output (Pin 24)
This pin is the line driver non–inverting output. A 7 dBm
(typ) differential output voltage can be obtained by connecting a 1.2 kΩ load resistor between Tx1 and Tx2. Attention
must be paid so as not to exceed this level when an external
input is added to the DSI pin. A telephone line (600 Ω) is driven through an external 600 Ω resistor (see the Application
Circuit). In this case, the output level becomes about a half of
the differential output.
TxA2
Inverting Transmit Analog Carrier Output (Pin 23)
This pin is the line driver inverting output. The signal is
equal in magnitude, but 180° out of phase with the TxA1
(refer to TxA1).
RxA
Receive Signal Input (Pin 25)
This pin is the carrier signal input, and is enabled when the
device is in FSK or CPTD mode.
RxGC
Receive Gain Adjust (Pin 26)
This pin is used to adjust the receive buffer gain. To adjust
the gain, a resistor may be added between this pin and the
RxBO pin (refer to the Block Diagram). This pin may be held
open when the gain adjustment is not needed.
RxBO
Receive Buffer Output (Pin 27)
This pin is the receive buffer output.
MOTOROLA
DTMF IN
DTMF Receive Input (AGC Amp Input) (Pin 5)
This pin is the receive DTMF signal input. It is enabled
when the device is in the DTMF receive mode.
AGC OUT
AGC Output (Pin 6)
This pin is used by the manufacturer to test the auto gain
control amplifier. It should be held open in normal operation.
DSI
Driver Summing Input (Pin 22)
This pin is the inverting input of the line driver. An external
signal may be transmitted through an external series resistor
RDSI. The differential gain GDSI = (VTxA1 – VTxA2)/VDSI
is determined by the following equation:
GDSI = – 2Rf / RDSI, Rf
X 20 kΩ
Note that the programmable transmit attenuator does not
affect in this case.
The DSI pin should be held open when not in use.
CDA
Carrier Detect Level/CPTD Level Control (Pin 4)
The carrier/call progress tone detect level is adjusted by
the CDA pin voltage.
When this pin is held open, the CDA voltage is set to
1.25 V (VCC = ± 5 V) by an internal divider. Then the detect
level is set at – 44 dBm (typ) for off to on, and – 47 dBm (typ)
for on to off, and the hysteresis is set minimum 2 dB. This pin
has a very high input impedance so it should be connected to
GND with a 0.1 µF capacitor to keep it under the regulations.
An external voltage may be applied to this pin to adjust the
carrier detect threshold. The following equations may be
used to find the CDA voltage required for a given threshold
voltage:
VCDA = 245 × Von
VCDA = 347 × Voff
TLA
Transmit Carrier Level Adjust (Pin 11)
This pin is used to adjust the transmit carrier level that is
determined by the value of the resistor (RTLA) connected
between this pin and the GND. The maximum level can be
obtained when this pin is shorted to GND (RTLA = 0).
FTLC1
FSK Filter Test (Pin 28)
This pin is a high–impedence filter output. It may be used
for testing the FSK filter characteristics, and is reserved for
manufacturer’s use only. In normal operation, this pin should
be decoupled to Vref with a 0.1 µF capacitor.
MOTOROLA
FTLC2
DTMF Receive Low Group Filter Test (Pin 7)
This pin is a high–impedence filter output. It may be used
for testing the DTMF receive high goup bandpass filter characteristics, and is reserved for manufacturer’s use only. In
normal operation, this pin should be decoupled to Vref with a
0.1 µF capacitor.
FTLC3
DTMF Receive High Group Filter Test (Pin 8)
This pin is a high–impedence filter output. It may be used
for testing the DTMF receive high group bandpass filter characteristics, and is reserved for manufacturer’s use only. In
normal operation, this pin should be decoupled to Vref with a
0.1 µF capacitor.
SERIAL CONTROL INTERFACE
The following six functions are determined by the 16 bits of
serial data in the control register.
CONTROL REGISTER
FUNCTION MODE
:
M3
M2
M1
M0
TRANSMIT ATTENUATOR
:
A3
A2
A1
A0
TRANSMIT TONE
FREQUENCY
:
T3
T2
T1
T0
TRANSMIT SQUELCH
:
SQ
CHANNEL
:
CH
CARRIER DETECT TIME
:
CD1
CD0
The received DTMF tones are indicated by the four bits of
data in the status register.
STATUS REGISTER
RECEIVE TONE FREQUENCY :
D3
D2
D1
D0
Figure 1 presents the timing diagram of 16–bit control register input and four–bit status output. When the R/W pin is in
logic low, the 16–bit data is captured into the control register
at the rising edge of SCK and latched in the mode control
logic to update the function mode at logic high input to the E
pin. When the R/W pin is in logic high, the status register is
selected to read out the received DTMF data, the four–bit
data in the DTMF decoder is loaded into the status register,
and the first bit (D0) is presented at the Data I/O on the rising
edge of E. The following bits are repeatedly shifted out as
D1–D2–D3–D0–D1–... by the rising edges of SCK.
CONTROL REGISTER BIT MAP DESCRIPTION
FUNCTION MODE (M3 to M0)
One of the following modes is selected from the four–bit
data (M3 to M0) shown in Table 1. Table 2 presents each output status; the functions are described below.
MC145446A
9
DTMF Receive Mode
Table 1. Function Mode Truth Table
M3
M2
M1
M0
0
0
0
0
FSK
Function Mode
0
0
0
1
FSK Analog Loopback
0
0
1
0
CPTD
DTMF Analog Loopback Mode
0
0
1
1
Answer Tone
0
1
0
0
DTMF Transmit
0
1
0
1
Single Tone
The transmitter, working as a DTMF tone generator, is internally connected to the receiver working as DTMF tone receiver. The DV goes low when the receiver detects a valid
DTMF tone. This feature is used for the device self test.
0
1
1
0
Power–Down 1
0
1
1
1
Power–Down 2
1
0
0
0
DTMF Receive
1
0
0
1
DTMF Analog Loopback
The receiver works as a DTMF tone receiver. The DV goes
low when a valid DTMF tone is detected. The transmitter is
disabled.
Single Tone Mode
The transmitter generates one of the eight frequencies of
the DTMF tone. The receiver is disabled.
Power–Down Mode 1
FSK Mode
Whole internal circuits, except the oscillator, are disabled
and all outputs except the X1 pin go to the high–impedance
state. The supply current decreases to 500 µA (max).
The transmitter and the receiver work as an FSK modulator/demodulator. The SD pin goes low when a valid FSK
signal is detected.
Power–Down Mode 2
DTMF Transmit Mode
The transmitter works as a DTMF tone generator. The
receiver is disabled.
CPTD (Call Progress Tone Detect) Mode
The receiver works as a 400 Hz call progress tone detector. The CD pin goes low when a valid call progress tone is
detected.
Answer Tone Mode
The transmitter works as a 2100 Hz answer tone generator. The receiver is disabled.
FSK Analog Loopback Mode
The transmitter, working as the FSK modulator, is internally connected to the receiver working as the FSK demodulator. This feature is used for the device self test.
Whole internal circuits, including the oscillator, are disabled and all outputs go to the high–impedance state. The
supply current decreases to 1.0 µA (max).
Transmit Attenuator/AGC Gain Set (A3 to A0)
Four–bit serial data (A3 – A0) sets up the analog transmit
level in the FSK, answer tone, DTMF, analog loopback, and
single tone mode. The range of the transmit attenuator is 0 to
15 dB in 1 dB steps. The attenuator, however, does not affect
the external signal input from the DSI. These bits also determine the AGC amplifier gain in the DTMF receive mode. In
normal operation, “Automatic” may be selected so that the
gain is automatically adjusted corresponding to the input signal level. See Table 3 for a detailed description.
Transmit Tone Frequency (T3 to T0)
These four bits (T3 to T0) determine the DTMF tone frequencies in DTMF transmit and DTMF analog loopback
mode, and determine the single tone frequency in the single
tone mode. Tone frequency assignments with reference to
T3 – T0 are shown in Table 4.
Table 2. Output Status
Output Pin
Function Mode
RxD
SD/CD/DV
TxA1, TxA2
Receive
Digital Data
Carrier
Detect Signal
FSK
Call Progress Tone
H
CPTD Signal
VCC/2
Answer Tone
H
H
Answer Tone
DTMF Transmit
H
H
DTMF Tone
Single Tone
H
H
Single Tone
High Impedance
High Impedance
High Impedance
H
DV Signal
VCC/2
FSK
FSK Loopback
Power–Down 1, 2
DTMF Receive
DTMF Loopback
MC145446A
10
DTMF Tone
MOTOROLA
Table 3. Transmit Attenuator/AGC Gain Set
Truth Table
A3
A2
A1
A0
Attenuation
(dB)
AGC Gain
Step (dB)
0
0
0
0
0
– 5.0
0
0
0
1
1
– 2.5
0
0
1
0
2
0.0
0
0
1
1
3
2.5
0
1
0
0
4
5.0
0
1
0
1
5
7.5
0
1
1
0
6
10.0
0
1
1
1
7
12.5
1
0
0
0
8
15.0
1
0
0
1
9
17.5
1
0
1
0
10
20.0
1
0
1
1
11
Clamp
1
1
0
0
12
Automatic
1
1
0
1
13
—
1
1
1
0
14
—
1
1
1
1
15
—
Table 4. Tone Frequency Truth Table
Tone Frequency (Hz)
DTMF Mode
MOTOROLA
T3/D3
T2/D2
T1/D1
T0/D0
Low
Group
High
Group
Keyboard
Equivalent
Single
Tone Mode
0
0
0
0
941
1633
D
941
0
0
0
1
697
1209
1
697
0
0
1
0
697
1336
2
697
0
0
1
1
697
1477
3
697
0
1
0
0
770
1209
4
770
0
1
0
1
770
1336
5
770
0
1
1
0
770
1477
6
770
0
1
1
1
852
1209
7
852
1
0
0
0
852
1336
8
1336
1
0
0
1
852
1477
9
1477
1
0
1
0
941
1336
0
1336
1
0
1
1
941
1209
*
1209
1
1
0
0
941
1477
#
1477
1
1
0
1
697
1633
A
1633
1
1
1
0
770
1633
B
1633
1
1
1
1
852
1633
C
1633
MC145446A
11
Transmit Squelch
Table 7. Carrier/DTMF Detect Time Truth Table
The 1–bit serial data (SQ) controls the transmit analog
squelch. The FSK signal, DTMF tones, single tone, and answer tone are disabled, then TxA1 and TxA2 will be clamped
to VCC/2 when the transmit squelch goes to the Enable (SQ
= 1) state. The transmit squelch does not affect the external
signal from the DSI.
Table 5. Transmit Squelch Truth Table
SQ
Squelch
1
Enable
0
Disable
FSK Mode
Carrier Detect Time
(typ)
DTMF Receive Mode
Carrier Detect Time
(typ)
ton (ms)
CD1
CD0
ton (ms)
toff (ms)
0
0
450
35
0
1
10
35
25
25
1
0
10
20
30
35
1
1
70
15
40
25
toff (ms)
Reserved
Power–On Reset
Channel
When the function mode is either on the FSK or analog
loopback mode, the transmit and receive channel is set up
with a 1–bit serial data (CH).
Table 6. Channel Truth Table
CH
Channel
1
1 (Originate)
0
2 (Answer)
Carrier Detect Time
The carrier and DTMF tone detect timing are determined
by two–bit serial data (CD1, CD0). The timing diagram is
shown in Figure 3.
MC145446A
12
When the power is switched on, this device is entered into
Power–Down Mode 2 by the internal power–on reset circuit.
STATUS REGISTER BIT MAP DESCRIPTION
Received Tone Frequency (D3 to D0)
This four–bit data (D3 to D0) indicates the received DTMF
tones. The first bit (D0) is presented at Data I/O on the rising
edge of E, and the following bits (D1–D2–D3–D0–D1– ...)
are shifted out and presented on the next rising edge of SCK.
The data configuration corresponding to each tone is
shown in Table 4.
MOTOROLA
100 µF
0.1 µF
10 Ω
600 : 600
TxA2
VREF
TIP
*
600 Ω
TxA1
FTLC1
RING
RxA
0.1 µF
DTMF IN
RxGC
FTLC2
0.1 µF
RxBO
MC145446A
TxD
RxD
FTLC3
0.1 µF
I/O PORT
SD/CD/DV
R/W
MCU
DATA I/O
CDA
0.1 µF
SCK
TLA
E
DSI
0.1 µF
100 µF
VCC
+5V
GND
*
LINE PROTECTION CIRCUIT
SYSTEM GROUND
REFERENCE ANALOG GROUND
Figure 5. Application Circuit
MOTOROLA
MC145446A
13
PACKAGE DIMENSIONS
FW SUFFIX
SOP
CASE 751M–01
VIEW AB
A
-Y-
28
15
B
-Z-
1
E
V X 45_ " 5_
14
D 28X
0.25 (0.010)
M
T Z
0.18 (0.007)
M
T
S
Y
0.18 (0.007)
S
M
T Y
S
Z
S
VIEW AB
CL
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2. CONTROLLING DIMENSION: MILLIMETER.
3. DIMENSIONS A AND B DO NOT INCLUDE MOLD
PROTRUSION. MAXIMUM MOLD PROTRUSION
SHALL NOT EXCEED 0.15 (0.006) PER SIDE.
4. DIMENSION D DOES NOT INCLUDE DAMBAR
PROTRUSION. DAMBAR PROTRUSION SHALL
NOT CAUSE THE LEAD WIDTH TO EXCEED 0.65
(0.026).
MILLIMETERS
MIN
MAX
17.80
18.03
7.40
7.62
2.65
2.25
2.45
0.35
0.51
10.00
10.60
0.40
0.70
1.27 BSC
0.10
0.25
0.635 BSC
8_
0.25
0.75
0.05
0.20
1.40 REF
DIM
A
B
C
C1
D
E
F
G
J
L
θ
V
W
X
INCHES
MIN
MAX
0.701
0.710
0.291
0.300
0.104
0.090
0.096
0.014
0.020
0.394
0.414
0.016
0.028
0.050 BSC
0.004
0.010
0.025 BSC
8_
0.010
0.030
0.002
0.008
0.110 REF
0.10 (0.004) T
C
J
C1
-T-
SEATING
PLANE
W
L
G
4X
24X
W REF
F
θ
Z
Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty, representation or guarantee regarding
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, and
specifically disclaims any and all liability, including without limitation consequential or incidental damages. “Typical” parameters which may be provided in Motorola
data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. 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
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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.
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51 Ting Kok Road, Tai Po, N.T., Hong Kong. 852–26629298
MC145446A
14
◊
*MC145446A/D*
MC145446A/D
MOTOROLA