SI2493-C-FS Silicon Laboratories Inc, SI2493-C-FS Datasheet - Page 201

• Manufacturer Part Number: SI2493-C-FS
• Description: IC ISOMODEM SYSTEM-SIDE 16SOIC
• Manufacturer: Silicon Laboratories Inc

Specifications of SI2493-C-FS

• Mfg Application Notes: SI2493/57/34/15/04, Appl Note AN93
• Data Format: V.21, V.22, V.23, V.29, V.32, V.34, V.90, V.92, Bell 103, Bell 212A
• Baud Rates: 56k
• Interface: UART
• Voltage - Supply: 3 V ~ 3.6 V
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

As shown in Figure 68, the V29FastPOS protocol looks different than the older, slower, V.22-like protocols. It is
also half-duplex, and each participating modem uses the entire spectral space available in the telephone line.
A receiving modem recognizes that the calling modem is V29-capable by detecting the V29 Calling tone at 980 Hz.
Another example with some more SDLC oriented data is provided later in this document.
DTMF dialing.
V29 Calling
Tone (980 Hz).
(2225 or 2100 Hz).
Answer Tone
Figure 68. Appearance of V29FastPOS Protocol
Answering modem
sends training pat-
terns and packet(s).
Rev. 0.9
Calling modem sends
training patterns and
packet(s).
Modem exchange packets.
AN93
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