描述 Description

Overview MC145745 removed from active portfolio. Possible replacement part: none.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 ohm 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.  

特性 Features

\t?Conforms to ITU V.21 and V.23 Recommendations
\t?DTMF Generator and Receiver for all 16 Standard Digits
\t?Capable of Driving 0 dBm into a 600 ohm Load (VCC = 5 V)
\t?Automatic Gain Control (AGC) Amplifier for the DTMF Receiver
\t?Call-Progress Tone Detector
\t?Four-Wire Serial Data Interface (SCP)
\t?Programmable Transmission and Carrier Detection Levels
\t?FSK/DTMF Analog Loopback Self-Test Function
\t?Crystal Oscillator (3.579545 MHz) and Half Divider Circuit (7.159090 MHz)
\t\tfor External Inputs
\t?Operates in the Voltage Range of 3.3 - 5.5 V
\t?Power Down Mode (ICC