The CH2100 is a full function, fully approved V.22bis 2400bps modem module. It is hermetically encapsulated and has a footprint that is less than one square inch. This makes the CH2100 unique in size, performance and reliability. The CH2100 interfaces directly to the telephone line utilizing its built in PSTN line interface. The modem is completely intelligent and is controlled by and will communicate via the five volt serial transmit and receive data pins exclusively. The CH2100 uses the standard AT commands and status words for command and control. No additional external pin connections are required. Even though all other vestigial modem signals have been eliminated, the CH2100 can communicate with any other commercially available modem up to and including 56Kbps modems. The CH2100 supports asynchronous operation at 2400bps, 1200bps, and 300bps to CCITT and Bell standards. Through-hole or surface mount pins are available. The user may select from standard temperature range or extended temperature range versions. The CH2100 is FCC part 68 approved (which is conveyed to the user), is UL1950 and CSA C22.2 950 compliant and is approvable in Canada to CSA CS03 Part I.