SI2457-C-FSR Silicon Laboratories Inc, SI2457-C-FSR Datasheet - Page 19
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SI2457-C-FSR
Manufacturer Part Number
SI2457-C-FSR
Description
Manufacturer
Silicon Laboratories Inc
Datasheet
1.SI2457-C-FSR.pdf
(74 pages)
Specifications of SI2457-C-FSR
Lead Free Status / RoHS Status
Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Part Number:
SI2457-C-FSR
Manufacturer:
SILICON LABS/芯科
Quantity:
20 000
4.13. Overcurrent Detection
The Si2457/34/15/04 includes an overcurrent detection
feature
programmable time after the Si2457/34/15/04 goes off-
hook. This allows the Si2457/34/15/04 to detect if it is
connected to an improper telephone line. The
overcurrent detection feature may be enabled by setting
the OCDM bit (U70, bit 11). OHT (U77, bits 8:0) sets the
delay after off-hook until the loop current is measured.
See “AN93: Modem Designer’s Guide” for details.
4.14. Global Operation
The Si2457/34/15/04 chipset contains an integrated
silicon direct access arrangement (Silicon DAA) that
provides a programmable line interface to meet
international telephone line interface requirements.
“AN93: Modem Designer’s Guide” gives the DAA
register settings required to meet international PTT
standards.
Additionally, the user-access registers (via the AT:U and
AT:R commands) may be programmed for country-
specific settings, such as dial tone, ring, ringback, and
busy tone. See “AN93: Modem Designer’s Guide” for
complete details.
that
LVCS
BITS
measures
30
25
20
15
10
5
0
0 3 6 9 12 15 18 21 24
the
loop
CTR21 only
27
current
30 33 36 39 42 45 48 51 54 57 60 63 66 69 72
Figure 8. Loop Current
at
Rev. 1.1
a
Loop Current
4.15. Firmware Upgrades
The Si2457/34/15/04 contains an on-chip program ROM
that includes the firmware required for the features
listed in this data sheet. In addition, the Si2457/34/15/04
contains on-chip program RAM to accommodate minor
changes to the ROM firmware. This allows Silicon Labs
to provide future firmware updates to optimize the
characteristics of new modem designs and those
already deployed in the field. See “AN93: Modem
Designer’s Guide” for complete details.
4.16. SMS / MMS Support
The
modulation. This modulation provides the low-level
functionality needed for SMS and MMS protocols. See
“AN93: Modem Designer’s Guide” for complete details.
4.17. Codec Interface (24-Pin Version Only)
In order to support a full range of voice and data
applications, the Si2457/34/15/04 includes an optional
serial interface that connects to an external voice codec
(Si3000). See “AN93: Modem Designer’s Guide” for
complete details.
(mA)
Si2457/34/15/04
75 78 81 84 87 90 93
Si2457/34/15/04
supports
Overload
V.23
140
half-duplex
19