MC145745 Datasheet, PDF (1/16 Pages) Motorola, Inc – V.21/V.23 TELEMETER MODEM

MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
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V.21/V.23 Telemeter Modem
The MC145745 is a selectable modem chip compatible with ITU V.21
(300 baud full duplex asynchronous) and V.23 mode 2 (1200 baud half duplex
asynchronous). The built–in differential line driver has the capability of driving
0 dBm into a 600 Ω load with a 5 V single power supply. This device also
includes a DTMF generator, DTMF receiver, call–progress tone detector,
answer tone generator, and a receive timing control circuit.
Besides having a clock generator with a crystal oscillator connected to it, the
device has a divider circuit to which input of a double frequency clock is possible
from external sources, such as from a microcontroller unit (MCU). The serial
control port (SCP) permits the MCU to access internal registers for exercising
the built–in features.
A low consumption device, the MC145745 integrates various functions in a
small package. This modem IC is best suited for telemeter and other
applications of this type.
• Conforms to ITU V.21 and V.23 Recommendations
• DTMF Generator and Receiver for all 16 Standard Digits
• Capable of Driving 0 dBm into a 600 Ω Load (VCC = 5 V)
• Automatic Gain Control (AGC) Amplifier for the DTMF Receiver
• Call–Progress Tone Detector
• Four–Wire Serial Data Interface (SCP)
• Programmable Transmission and Carrier Detection Levels
• FSK/DTMF Analog Loopback Self–Test Function
• Crystal Oscillator (3.579545 MHz) and Half Divider Circuit (7.159090 MHz)
for External Inputs
• Operates in the Voltage Range of 3.3 – 5.5 V
• Power Down Mode (ICC < 1 µA)
Order this document
by MC145745/D
MC145745
28
1
FW SUFFIX
SOIC
CASE 751M
ORDERING INFORMATION
MC145745FW SOIC
PIN ASSIGNMENT
GND 1
Vref 2
CDA 3
TLA 4
TEST 1 5
RxD 6
TxD 7
CD 8
CLKO 9
X1 10
X2 11
ECLK 12
PB0 ₁₃
GND 14
28 VCC
27 RxA
26 TxA1
25 TxA2
24 TEST 2
23 SCPEN
22 SCPCLK
21 SCP Rx
20 SCP Tx
19 RESET
18 PB3
17 PB2
16 ^PB1
15 VCC
This document contains information on a product under development. Motorola reserves the right to change or discontinue this product without notice.
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MC145745
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