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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)： | 9/14頁 |
| 文件大?。?/td> | 264K |
| 代理商： | MC145446 |
MC145446A
MOTOROLA
9
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
Note that the programmable transmit attenuator does not
affect in this case.
The DSI pin should be held open when not in use.
20 k
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
μ
F 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
μ
F capacitor.
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 char-
acteristics, and is reserved for manufacturer’s use only. In
normal operation, this pin should be decoupled to Vref with a
0.1
μ
F 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 char-
acteristics, and is reserved for manufacturer’s use only. In
normal operation, this pin should be decoupled to Vref with a
0.1
μ
F capacitor.
SERIAL CONTROL INTERFACE
The following six functions are determined by the 16 bits of
serial data in the control register.
T3
T2
T1
T0
CD1
CD0
A2
A1
A0
TRANSMIT TONE
FREQUENCY
:
CARRIER DETECT TIME
:
CHANNEL
:
SQ
TRANSMIT SQUELCH
:
FUNCTION MODE
:
TRANSMIT ATTENUATOR
:
CH
A3
CONTROL REGISTER
M2
M1
M0
M3
The received DTMF tones are indicated by the four bits of
data in the status register.
D3
D2
D1
D0
RECEIVE TONE FREQUENCY:
STATUS REGISTER
Figure 1 presents the timing diagram of 16–bit control reg-
ister 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 out-
put status; the functions are described below.
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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 |
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| MC145447P | 制造商:Motorola Inc 功能描述: |
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