Description

MAS9138 is a single chip duplex asynchronous to synchronous converter. It converts asynchronous start stop characters to synchronous format, with stop bit deletion when required as defined in the CCITT recommendation V.14. On the receiver channel MAS9138 converts the incoming synchronous data to asynchronous start stop character format with stop bit insertion when required as defined in the CCITT recommendation V.14. MAS9138 implements the data modes for the synchronous interface as specified in the V.14. MAS9138 can be configured to operate at any frequency up to 38.4 kbits/s within these modes. The device contains a bit generator and frequency selection logic to allow easy operation at other data rates. With just one crystal the device can adapt to ten (10) different bit rates so it is ideally suited to be used with the most common modem systems ranging from V.22 to V.34.

Specifications and features

• Implements CCITT recommendation V.14
• Bypass operation
• Character length from 8 to 11 bits including start stop and parity bits
• CMOS and LS-TTL compatible interface
• Low power consumption (typically 10 mW)
• No additional circuitry needed to perform conversion
• Single +3.3...+5V supply
• Operating temperature -40°C to 85°C
• 16-pin PDIP and SO package

Application Scenarios

• Data communication systems
• Adapts asynchronous terminals to synchronous modems
• Full or half card PC modems using UART as a data source
• Simplifying data multiplexing systems