Si2401
V. 22
B I S
I S O
M O D E M ® W I T H
I
N T E G R A T E D
G
L O B A L
D A A
Features
Data modem formats
2400 bps: V.22bis
1200 bps: V.22, V.23, Bell 212A
300 bps: V.21, Bell 103
Fast connect and V.23 reversing
SIA and other security protocols
Integrated third-generation DAA
Fewer external components required
Over 5000 V capacitive isolation
Parallel phone detect
Globally-compliant line interface
27 MHz CLKIN support
Caller ID detection and decoding
UART with flow control
AT command set support
Call progress support
3.3 V Power
Lead-free, RoHS-compliant
packages
Ordering Information
See page 72.
Applications
Set-top boxes
Point-of-sale
ATM terminals
Security systems
Medical monitoring
Power meters
Pin Assignments
Si2401
CLKIN/XTALI
XTALO
GPIO5/RI
V
D
RXD
TXD
CTS
RESET
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
GPIO1/EOFR
GPIO2/CD
GPIO3/ESC
V
A
GND
GPIO4/INT/AOUT
C1A
C2A
Description
The Si2401
is a complete, two-chip 2400 bps modem integrating
Silicon Labs’ third-generation direct access arrangement (DAA), which provides a
globally-programmable telephone line interface with an unprecedented level of
integration. Available in two 16-pin SOIC packages, this compact solution
eliminates the need for a separate DSP data pump, modem controller, codec,
isolation transformer, relay, opto-isolators, and 2–4 wire hybrid. The Si2401
provides conventional data formats at connect rates of up to 2400 bps with full-
duplex operation over the Public Switched Telephone Network (PSTN).
Additionally, the Si2401 is fully-programmable to meet global standards with a
single design. Other features include fast connect times for electronic point-of-
sale (EPOS) applications and alarm protocols for security systems. The device is
ideal for embedded modem applications due to its small size, low external
component count, and low power consumption.
ISOmodem
®
Si3010
QE
DCT
RX
IB
C1B
C2B
VREG
1
2
3
4
5
6
7
8
16
15
14
13
12
11
10
9
DCT2
IGND
DCT3
QB
QE2
SC
VREG2
RNG2
Functional Block Diagram
Si2401
UART
RXD
TXD
CTS
RESET
EOFR/GPIO1
CD/GPIO2
ESC/GPIO3
INT/GPIO4
RI/GPIO5
XTALI
XOUT
Clock
Interface
Control
Interface
Si3010
RX
RNG1
µ Controller
(AT Decoder,
Call Progress)
Isolation Interface
Hybrid, AC
and DC
Terminations
Isolation
Interface
DSP
(Data Pump)
IB
SC
DCT
VREG
VREG2
DCT2
DCT3
U.S. Patent #5,870,046
U.S. Patent #6,061,009
Other patents pending
Ring Detect
Off-Hook
RNG1
RNG2
QB
QE
QE2
Rev. 1.0 12/05
Copyright © 2005 by Silicon Laboratories
Si2401
This information applies to a product under development. Its characteristics and specifications are subject to change without notice.
Si2401
2
Rev. 1.0
Si2401
T
A B L E O F
C
O N T E N TS
Section
Page
1. Electrical Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4
2. Typical Application Schematic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3. Bill of Materials: Si2401/10 Chipset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4. Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.1. Serial Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.2. Configurations and Data Rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.3. Low Power Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.4. Global DAA Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.5. Parallel Phone Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.6. Interrupt Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
4.7. V.23 Operation/V.23 Reversing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
4.8. V.42 HDLC Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
4.9. Fast Connect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23
4.10. Clock Generation Subsystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
5. AT Command Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24
5.1. Command Line Execution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
5.2. <CR> End-Of-Line Character . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
5.3. AT Command Set Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
5.4. Alarm Industry AT Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
5.5. Modem Result Codes and Call Progress . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
6. Low Level DSP Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
6.1. DSP Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
6.2. Call Progress Filters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
7. S Registers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
8. Pin Descriptions: Si2401 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69
9. Pin Descriptions: Si3010 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71
10. Ordering Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
11. Package Outline: 16-Pin SOIC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
Document Change List . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .74
Contact Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .76
Rev. 1.0
3
Si2401
1. Electrical Specifications
Table 1. Recommended Operating Conditions
Parameter
1
Ambient Temperature
Si2401 Supply Voltage, Digital
3
Symbol
T
A
V
D
Test Condition
F-Grade
Min
2
0
3.0
Typ
25
3.3
Max
2
70
3.6
Unit
°C
V
Notes:
1.
The Si2401 specifications are guaranteed when the typical application circuit (including component tolerance) and Si2401
and Si3010 are used. See "2. Typical Application Schematic" on page 10.
2.
All minimum and maximum specifications are guaranteed and apply across the recommended operating conditions. Typical
values apply at nominal supply voltages and an operating temperature of 25 °C unless otherwise stated.
3.
The digital supply, V
D
, operates from 3.0 to 3.6 V. The Si2401 interface supports 5 V logic (CLKIN/XTALI supports 3.3 V
logic only).
4
Rev. 1.0
Si2401
Table 2. Loop Characteristics
(V
D
=
3.0 to 3.6 V, T
A
=
0 to 70 °C for F-Grade, see Figure 1 on page 6)
Parameter
DC Termination Voltage
DC Termination Voltage
DC Termination Voltage
DC Termination Voltage
DC Termination Voltage
DC Termination Voltage
DC Termination Voltage
On-Hook Leakage Current
Operating Loop Current
Operating Loop Current
DC Ring Current
Ring Detect Voltage
*
Ring Detect Voltage
*
Ring Frequency
Ringer Equivalence Number
Symbol
V
TR
V
TR
V
TR
V
TR
V
TR
V
TR
V
TR
I
LK
I
LP
I
LP
Test Condition
I
L
= 20 mA, ILIM = 0
DCV = 00, MINI = 11, DCR = 0
I
L
= 120 mA, ILIM = 0
DCV = 00, MINI = 11, DCR = 0
I
L
= 20 mA, ILIM = 0
DCV = 11, MINI = 00, DCR = 0
I
L
= 120 mA, ILIM = 0
DCV = 11, MINI = 00, DCR = 0
I
L
= 20 mA, ILIM = 1
DCV = 11, MINI = 00, DCR = 0
I
L
= 60 mA, ILIM = 1
DCV = 11, MINI = 00, DCR = 0
I
L
= 50 mA, ILIM = 1
DCV = 11, MINI = 00, DCR = 0
V
TR
= –48 V
MINI = 00, ILIM = 0
MINI = 00, ILIM = 1
dc current flowing through ring
detection circuitry
Min
—
9
—
9
—
40
—
—
10
10
—
12
18
15
—
Typ
—
—
—
—
—
—
—
—
—
—
1.5
15
21
—
—
Max
6.0
—
7.5
—
7.5
—
40
5
120
60
3
18
25
68
0.2
Unit
V
V
V
V
V
V
V
µA
mA
mA
µA
V
RMS
V
RMS
Hz
V
RD
V
RD
F
R
REN
RT = 0
RT = 1
*Note:
The ring signal is guaranteed to not be detected below the minimum. The ring signal is guaranteed to be detected
above the maximum.
Rev. 1.0
5
