74VHC943 is a full duplex low speed modem for data communication over telephone lines and other narrow bandwidth channels. It provides a 300 baud bidirectional serial interface and is Bell 103 compatible. The 74VHC943 utilizes advanced silicon-gate CMOS technology. Switched capacitor techniques are used to perform analog signal processing. The modulator section contains a frequency synthesizer and a sine wave synthesizer, producing a phase coherent frequency shift keyed (FSK) output. The line driver and hybrid section are designed to facilitate connection to a 600X telephone line, they can perform two to four wire conversion and drive the line at a maximum of b9 dBm. The demodulator section incorporates anti-aliasing filters, a receive filter, limiter, discriminator, and carrier detect circuit. The nine-pole receive filter provides 60 dB of transmitted tone rejection. The discriminator is fully balanced for stable operation.
The 74VHC943 is a full duplex low speed modem utilizing advanced silicon-gate CMOS technology. It provides a 300 baud bidirectional serial interface for data communication over telephone lines and other narrow bandwidth channels, fully compatible with the Bell 103 standard.
The device integrates a modulator section containing a frequency synthesizer and sine wave synthesizer to produce phase coherent FSK output. It also includes a line driver and hybrid section designed for connection to a 600Ω phone line, performing two-to-four wire conversion. The demodulator incorporates anti-aliasing filters and a nine-pole receive filter providing 60 dB of transmitted tone rejection.
| Supply Voltage | 5V |
|---|---|
| Data Rate | 300 baud |
| Standard Compatibility | Bell 103 |
| Operating Temperature Range | -40°C to +85°C |
| Storage Temperature Range | -65°C to +150°C |
| Maximum Supply Voltage | +7.0V |
The device provides a 300 baud bidirectional serial interface.
Yes, the 74VHC943 is fully compatible with the Bell 103 standard.
The device operates on a +5V supply, with an absolute maximum of +7.0V.