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參數(shù)資料
| 型號： | MC145446 |
| 廠商： | Motorola, Inc. |
| 英文描述： | Single-Chip 300-Baud Modem with DTMF Transceiver |
| 中文描述： | 單芯片300波特調(diào)制解調(diào)器的雙音多頻收發(fā)器 |
| 文件頁數(shù)： | 8/14頁 |
| 文件大?。?/td> | 264K |
| 代理商： | MC145446 |
MC145446A
8
MOTOROLA
PIN DESCRIPTIONS
VCC
Positive Power Supply (Pins 1, 13, 21)
The digital supply pins, which are connected to the positive
power supply (5 V).
GND
Ground Pins (Pins 2, 12)
The ground pins are connected to the system ground.
Vref
Reference Analog Ground (Pin 3)
This pin provides the analog ground voltage, which is inter-
nally regulated to VCC/2. It should be decoupled to the GND
with 0.1
μ
F and 100
μ
F 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 deter-
mines 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.
TxD
Transmit Data Input (Pin 17)
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.
RxD
Receive Data Output (Pin 16)
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 re-
ceived.
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 connect-
ing a 1.2 k
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
) is driv-
en through an external 600
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.
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相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| MC145446AFW | 制造商:Rochester Electronics LLC 功能描述:- Bulk 制造商:Motorola Inc 功能描述: 制造商:MOTOROLA 功能描述: |
| MC145447DW | 制造商:Motorola Inc 功能描述:CALLER NUMBER ID CIRCUIT, 16 Pin, Plastic, SOP |
| MC145447DWR2 | 制造商:Motorola Inc 功能描述:TELEPHONE MULTIFUNCTION CKT, 16 Pin Plastic SOP |
| MC145447P | 制造商:Motorola Inc 功能描述: |
| MC145475DW | 制造商:Motorola Inc 功能描述:DATACOM, ISDN CONTROLLER, PDSO28 |
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