SI2457-C-FT Silicon Laboratories Inc, SI2457-C-FT Datasheet - Page 20

• Manufacturer Part Number: SI2457-C-FT
• Description: IC ISOMODEM SYSTEM-SIDE 24TSSOP
• Manufacturer: Silicon Laboratories Inc

Specifications of SI2457-C-FT

• Package / Case: 24-TSSOP
• Mfg Application Notes: SI2493/57/34/15/04, Appl Note AN93
• Data Format: V.21, V.22, V.23, V.32, V.34, V.90, Bell 103, Bell 212A
• Baud Rates: 56k
• Interface: Parallel, UART
• Voltage - Supply: 3 V ~ 3.6 V
• Mounting Type: Surface Mount
• Operating Frequency: 4.92 MHz
• Supply Voltage (max): 3.6 V
• Supply Voltage (min): 3 V
• Supply Current: 26 mA
• Operating Temperature Range: 0 C to + 70 C
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

Si2457/34/15/04
4.18. EEPROM Interface
(24-Pin Version Only)
The Si2457/34/15/04 supports an optional serial
peripheral interface (SPI) bus serial EEPROM Mode 3
with a 16-bit (8–64 kbit range) address. Upon powerup,
if a pulldown resistor ≤10 kΩ is placed between D6
(Si2457, pin 4) and GND (see Table 8), the ISOmodem
attempts to detect an EEPROM. The EEPROM is
intended first for setting custom defaults, second for
automatically loading firmware upgrades, and third to
allow for user-defined AT command macros for use in
custom AT commands or country codes. See “AN93:
Modem Designer’s Guide” for complete details.
4.19. AT Commands
At powerup, the Si2457/34/15/04 is in the AT command
mode. In command mode, the modem monitors the
input (serial or parallel) checking constantly for a valid
command (AT commands are described in Table 10.)
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Rev. 1.1