HIGH SPEED Modem and FAX FAMILY
CH2056/TBR/ETBR – V.90 / 57,600bps/TBR21
CH1799/TBR/ETBR – V.34bis / 33,600bps/TBR21
CH1794
– V.32bis / 14,400bps
2003 Cermetek Microelectronics, Inc.
Page 1
Document No. 607-0003 Revision K3 (09/03)
FEATURES
•
Supports V.90, V.34bis, V.34, V.32bis, V.32,
V.22bis, V.22A/B, V.23, V.21, Bell 212A and 103.
•
CH2056 supports V.80 Synchronous operation.
•
Error correcting: V.42 LAMP, MNP 2-4 and
MNP10.
•
Data Compression: V.42bis and MNP 5
•
MNP10 Data through put enhancement for cellular
operation.
•
DTE serial interface with speeds up to 230.4kbps
(CH2056), 115.2 (CH1799) or 57.6kbps (CH1794).
•
Automatic baud rate adaptability utilizing speed
sensing, flow control and data buffers.
•
Send & Receive FAX class 1, Group 3 supported.
•
Serial V.24, 5 volt interface.
•
NVRAM directory and stored profiles.
•
AT Command structure, with extensions.
•
Built-in DAA with 1500 VAC RMS isolation 2122V
peak surge protection.
•
UL 1950 and CSA C22.2 950 Recognized
(E104957).
•
Leased Line version available CH1799LL
•
FCC part 68 Approved/DOT CSA CS-03 Part I
Approvable.
•
+5 Volt operation with zero power option
•
Small size: 1.35” x 1.38” x 0.61” (nominal, 0.55”
upon request).
•
Pin compatible with low speed/low cost CH1786
•
TBR21 compliant versions available:
CH1799TBR/ETBR and CH2056TBR/ETBR.
INTRODUCTION
The CH2056, CH1799 and CH1794 (HS Modem
Family) are industrial grade high-speed modem
modules. Each HS Modem product supports a range
of modem standards and speeds from 300bps to
14,400bps, 28,800bps, 33,600bps or 57,600bps. By
using built in compression algorithms the operation
speed can be expanded to the maximum DTE rate of
57.6kbps for the CH1794, 115.2kbps for the CH1799
and 230.4kbps for the CH2056. A choice of error
correcting schemes is available including MNP 10 for
cellular telephone applications. The HS Modem family
supports Send and Receive FAX. The CH1799LL
operates exclusively on non-voltage bearing leased
line.
The HS Modem family is pin compatible with
Cermetek’s low cost CH1786 V.22bis, 2400bps
modem family. Each module in the HS Modem family
is a self-contained modem and is FCC Part 68
approved and Canadian DOT approvable.
Additionally, the CH1799TBR/ETBR and the
CH2056TBR/ETBR products meet the European
TBR21 requirements.
These ultra small modules are designed for PCB
through-hole mounting and are 1.35” x 1.38” x 0.61”
(nominal, 0.55” upon request) in size. The HS Modem
family requires only two external interfaces: a CCITT
V.24 serial interface for direct access to a UART, and
a Tip and Ring RJ-11C Jack for the PSTN line
connection. The HS Modem can be controlled with
industry standard AT commands and is compatible
with available industry communication software.
DESCRIPTION OF FUNCTIONAL BLOCKS
AND DISCUSSION OF BASIC OPERATIONS
Figure 1 contains a functional block drawing of the HS
Modem family of products. Each HS Modem product
consists of a serial interface buffer,
modulator/demodulator, modem controller with error
correction and data compression, non-volatile RAM
and a DAA.
Figure 1. Functional Block Diagram of HS Modem
Family.
Serial Host Interface Buffer.
The HS Modem utilizes
a serial V.24 EIA 232-E 5V interface to control the
modem. The HS Modem products can communicate
over the serial interface with the Data Terminal
