CH2000 [ETC]
Telecommunication IC ; 电信IC\n
| 型号： | CH2000 |
| 厂家： | 
ETC |
| 描述： | Telecommunication IC
|
| 文件： | 总12页 (文件大小：1180K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
CH2000 Low Profile Full Function
2400 bps Modem
Cermetek
microelectronics
INTRODUCTION
At 0.34 inches (nominal), Cermeteks CH2000 is the lowest
profile full function FCC Part 68 approved modem
commercially available. It has been designed to be used in
applications where an extremely low profile is required. The
CH2000 fully supports V.22bis and associated standards
and is controlled through the AT command set.
FEATURES
Supports Standards CCITT V.22bis, V.22,
Bell 212, and Bell 103
FCC Part 68 approved and DOT CSA CS-03 Part I
approvable
AT Command structure available
1000 VAC isolation barrier
Single 5 volt operation
Low power sleep mode
Figure 1. Functional Block Diagram of CH2000.
Automatic adaptive and fixed compromise
equalization
Test modes and diagnostics
Size: 2.0 x 1.12 x 0.34 (nominal)
NVRAM allows storage of custom configurations
and telephone numbers
Commercial Operating temperature 0o to 70oC
Extended temperature -40oC to 85oC order
CH2000ET
equivalent. This label should be prominently displayed on any
system containing the CH2000. With the exception of the U.S.,
most countries (including Canada) require submission of the
final product or system containing the CH2000 for regulatory
agency approval. This is typically done by submitting the design
to a test house or consultant for evaluation against the applicable
regulatory standards. Call Cermetek for a consultant list.
Non-Volatile RAM (NVRAM).
DESCRIPTION OF FUNCTIONAL BLOCKS
The NVRAM present on the CH2000 is sufficient to store up to two
user customized modem configurations. The AT&Wn command
will store the active modem configuration in the selected NVRAM
locations by specifying an n of 0 or 1. The AT&Yn command selects
the modem configurations to be automatically recalled and made
active upon a reset or power up. The ATZn command immediately
recalls and activates a stored configuration. Refer to Tables 4 and
5 for storeable S-Registers and available commands.
AND DISCUSSION OF BASIC OPERATIONS
Figure 1 contains a functional block diagram of the CH2000.
The CH2000 is a highly integrated, full function modem,
comprised of a modulator/demodulator, controller, NVRAM
(Non-Volatile Ram) and an FCC Part 68 approved telephone
interface (Data Access Arrangement -DAA).
Modulation/Demodulation and Modem
Controller.
These functions are provided by a monolithic modem inte-
grated circuit. This IC has built-in facilities accomodating
integrated AT command control and containing the nec-
essary resident interfaces for general communication and
routing to the DAA.
SUPPORTED FEATURES
AT Command Set.
The CH2000 supports a 40-character command line. The com-
mand line starts with AT and may contain standard or enhanced
commands.
See Cermeteks command summary at
(www.cermetek.com), for a detailed discussion of AT Commands.
Serial Host Interface.
The CH2000 utilizes a V.24 (EIA-232-D) compatible interface. Refer
to the pin descriptions in Table 2.
Telephone Line Interface or DAA.
The CH2000 is designed to comply with North American telephone
standards as set by FCC Part 68 (USA) and DOT CSA CS-03
Part I (Canada). Among the more critical parameters, the CH2000s
telephone line interface provides 1000VAC and 1500 volt peak
surge isolation. Consequently, the CH2000 satisfies U.S. and
Canadian requirements and will meet other international require-
ments that specify this high level of isolation. The CH2000 is FCC
Part 68 preapproved and is shipped from the factory with an FCC
Part 68 approval label indicating the registration number and ringer
Speaker Interface.
The SPK output reflects the receiver analog input and provides a
signal that can be used to monitor call progress. The SPK signal
can drive a 300 Ω load directly. Typically, the SPK signal is input
into an audio power amplifier and the amplifier, inturn, drives a
speaker coil.
1999 Cermetek Microelectronics, Inc.
Document No.607-0002 Rev. D (8/99)
1
The speaker is activated with the ATMn command. The speaker
volume is adjusted using the ATLn command, where n is 0, 1, 2,
or 3. Increasing numbers correspond to higher volume. Figure 5
illustrates one technique of driving an external 8Ω speaker.
Table 1. Connection Rates.
Answering Modem Initial Connection Rate Resulting When
Trained Rate
Calling Modem Initial Trained Rate is:
300
1200
2400
Phone Control.
300
300
1200
1200
Cermeteks CH2000 contains a pin called Voice/Data (V/D). The
V/D pin toggles high when the modem goes off hook. This pin
can be used to activate a relay which can switch a telephone on
or off the Tip and Ring incoming PSTN lines. This feature allows
any telephone associated with the CH2000 to be disconnected
when a data call is in progress, thereby preventing the data from
being disturbed by an inadvertent telephone pick-up. See Figure
2.
1200
300
300
1200
1200
1200
2400
2400
Speed and Parity Selection.
Prior to call initiation, the host controller trains the modem to the
host speed (2400, 1200, or 300 bps) and parity (odd, even, mark,
space, or none) via a host-initiated training sequence. This train-
ing also sets the speed of the data for originate calls. The CH2000
will automatically adjust to the originators speed when answering
calls.
RING
RJ-11
Jack
OPTIONAL
PHONE
TIP
TIP
RJ-11
Jack
TELEPHONE
LINE
RING
The CH2000 matches the hosts parity when it returns status mes-
sages to the host. During a data connection, however, the modem
passes parity through without interpretation or alteration.
Ring Indicator (RI).
The RI pin toggles low when the CH2000 detects an incoming call.
Although not TTL compliant, the RI pin can, nonetheless, be uti-
lized to activate external circuitry including the external RST pin.
When using the RI pin, it is recommended that a Schmitt Trigger or
the Isolated Envelope Detect Circuit in Figure 4 be placed between
the RI pin and the external load.
Figure 2. Voice/Data Port Control.
Sleep Mode.
To minimize power consumption, the CH2000 includes a power
down feature called Sleep Mode. When activated, the CH2000
will automatically enter Sleep Mode after 0 to 254 seconds of inac-
tivity. The inactivity delay is selected using the ATS24 command.
The CH2000 is delivered from the factory with a 5 second inactivity
delay enabled (i.e., ATS24=5). The CH2000 returns to normal
operation when a ring signal is received or upon an input low
signal on the TXD pin. ATS24 = 255 disables the Sleep Mode and
is the default if no value is set in register S24.
Power Supply.
The CH2000 modem module is a complex set of sub-systems.
During the course of normal operation the CH2000 decodes ana-
log signals from the telephone line that are in the millivolt range.
Steps must be taken by the user to guarantee that power supply
noise on all supply lines, including ground, does not exceed 50
mV peak to peak. Any frequency between 20 kHz and 150 kHz must
be less than 500 µV peak. If necessary, use dedicated power and
ground planes. Failure to provide such operating conditions could
cause the CH2000 to malfunction or to function erratically.
A SLEEP output signal is available to control power to external
devices. In Figure 5, a FET controlled by the SLEEP signal turns
off the external speaker amplifier when the CH2000 enters Sleep
Mode. In Sleep Mode, power is reduced to approximately 50% of
normal operating power.
The CH2000 requires a single +5V ±5% supply. It is recommended
that by-pass capacitors be placed on the power supply as close to
the modems supply input as practical. It is recommended that a
10 µF Electrolytic capacitor in parallel with a 0.01µF ceramic ca-
pacitor be used.
Transmission Speed.
In normal operation, the originating modem initiates the call and
attempts to connect to the answering modem at a speed estab-
lished by the originating modems controller prior to call initiation.
This is referred to as the Initial Trained Rate. Upon receiving the
call, the answering modem will attempt to connect to the originat-
ing modem at its Initial Trained Rate.
WARNING: The CH2000 has been FCC Part 68 approved as a
data modem only. Utilization of the Voice/Tone Port requires further
registration. FCC will require that the system, including the CH2000
and the handset or DTMF transceiver, adhere to Part 68 rules.
If these two rates are identical, the connection is made. If the
speeds differ, the answering modem must adjust its rate or termi-
nate the call. Table 1 indicates the connection rate that will result
when the calling modems Inital Trained Rate and the answering
modems Initial Trained Rate are different.
MODEM CONTROL
The CH2000 modem may be controlled by sending serial ASCII
command sequences. The commands are sent to the modem
serially on the TXD pin. After execution of a received command, the
modem returns a serial status message that can be read on pin
RXD. This message indicates command completion status. Re-
fer to Table 3 for a complete list of result codes.
Note that a 2400 baud connection rate will only result if both mo-
dems are initially set at 2400 baud.
1999 Cermetek Microelectronics, Inc.
Document No. 607-0002 Rev. D (8/99)
2
INITIALIZING THE MODEM
MECHANICAL RELAY ONLY.
ZERO IMPEDANCE SWITCH MAY REPLACE
THE RELAY AND TRANSISTOR CIRCUIT.
Before commands may be sent to the CH2000, the modem must
be initialized. This consists of two events:
1) Power-up reset . This is accomplished by applying a hardware
reset pulse to pin RST.
A
ENABLE RXA
4.7K
+5V
2N2222
1N914
+15V
1
2
RING
TIP
20K
2) Initial modem training. The modem must be trained to the
hosts speed (2400, 1200, 300bps) and parity (odd, even, mark,
space or none).
CH2000
NC
34
33
32
3
B
4
A
499
1
+
GND
VCC
20K
7
2
AXT
RXA
DTR
-
8
9
31
30
29
RXD
NC
NC
TL064
2.2uF
nonpolar
NC
0.1uF
0.1uF
10 V/D
RST
82K
0.1uF
11
NC 28
20K
12RI
13NC
27
SPK
These activities are briefly described below.
26
NC
63.4K
14
15
16
NC 25
24
NC 23
22
DSR
NC
NC
VOICE OR DTMF
SIGNAL
20K
TXD
17NC
HS
Power-up Reset.
R1
54K
DCD 21
GND 20
18NC
19SLEEP
After applying power to the CH2000, the CH2000 generates an
internal reset pulse. The user can also reset the modem exter-
nally by applying a high-going reset pulse to the RST pin for at
least 10ms after the +5V power supply has stabilized. Delay send-
ing commands to CH2000 for 200ms after Power-up reset has
been initiated to allow the CH2000 to properly reset.
6
5
-
+
7
AXR
0.1uF
11
28K
R2
TL064
0.1uF
Training the Modem.
ADJUST R2 FOR THE DESIRED LEVEL OF AXT VOICE TO BE ECHOED TO AXR.
DECREASE RECEIVE GAIN SIGNAL AXR BY DECREASING VALUE OF R1.
Each modem must be trained to match its hosts speed and parity
so that it is able to recognize serial asynchronous commands
sent to it by the host UART. The host must retrain the modem each
time a reset signal is applied on RST or after a RESET serial
command has been issued.
Figure 3. Voice/Tone Injection.
RING
RJ-11
JACK
RXA
TXA
ANALOG VOICE
INJECTED SIGNALS
TIP
TELEPHONE
LINE
OPTIONAL
PHONE
CONTROL
RELAY
VOICE/DATA
SPK
SPEAKER
CONTROL
CH2000
RXD
HS
DCD
DSR
RI
V.24
EIA-232-D
INTERFACE
OR
CTS
USART
TXD
DTR
RST
EXTERNAL RESET
+5V
GND
EARTH GND
*
Figure 4. CH2000 Application Diagram of Test Circuit.
1999 Cermetek Microelectronics, Inc.
Document No.607-0002 Rev. D (8/99)
3
Table 2. CH2000 Pin Descriptions (Continued).
PIN
N AME
I/O
FU N C TION
GR OU N D . Note: Noise should be less than 50mV peak to peak.
20
21
GND
-
____
DCD
D ATA C AR R IER D ETEC T output. LOW indicates a data carrier from a remote
modem is detected. DCD follows carrier is the default.
O
__
HS
SPEED IN D IC ATION . High speed select output. A LOW on this pin indicates the
modem is operating at 2400bps.
22
23
O
-
NC
No connection.
24
25
NC
NC
-
-
No connection.
No connection.
26
27
NC
-
No connection.
SPEAK ER . Audio Output. See Figure 5.
SPK
O
28
29
30
31
32
NC
NC
NC
-
-
No connection.
No connection.
No connection.
-
____
RXD
R EC EIVE D ATA. Serial receive data output. Received marking or a binary 1
condition is indicated by a HIGH.
O
-
POWER SU PPLY. 5 Volts + 5% is required. Note: Noise should be less than
50mV peak to peak.
VCC
GR OU N D . Note: Noise should be less than 50mV peak to peak.
33
34
GND
NC
-
-
No connection.
Notes: (1) If VCC has a slow power up ramp time, the internal reset may be ineffective.
(2) I means input only.
(3) O means output only.
(4) I/O means both input and output possible.
(5) NC means no connection.
1999 Cermetek Microelectronics, Inc.
Document No. 607-0002 Rev. D (8/99)
4
Modem Training Command Sequence.
by the user.
The CH2000 is trained by sending it the following sequence:
X0 - Result Codes 0, 1, 2, 3, 4 allowed
X1 - Result Codes 0, 1, 2, 3, 4, 5, 10 allowed
X2 - Result Codes 0, 1, 2, 3, 4, 5, 6, 10 allowed
X3 - Result Codes 0, 1, 2, 3, 4, 5, 7, 10 allowed
X4 - Result Codes 0, 1, 2, 3, 4, 5, 6, 7, 10 allowed
Enter: AT[CR]
Where: A and T may be either upper or lower case but must be the
same case.
[CR] repesents carriage return
The CH2000 is factory set to X4, which allows all result codes.
The AT sequence is referred to as an attention sequence. The
CH2000 will respond with one of the following status messages,
depending on whether it is optioned for abbreviated or English
status messages.
MODEM STATES
The CH2000 can be in either command mode or data mode. When
the modem is idle, it is in command mode by default. When data
transmission is in progress, the CH2000 is in the data mode state
and will not recognize commands. To force the CH2000 to recog-
nize commands, the host must send an escape sequence to the
CH2000 forcing it out of data mode and into command mode.
Result: 0[CR]
(Abbreviated form)
Result: [CR][LF]OK[CR][LF] (English form)
Where: [CR] represents carriage return (ASCII 13 or HEX 0D).
[LF] represents line feed (ASCII 10 or HEX 0A).
The modem is now in idle mode and is ready to accept com-
mands.
The escape sequence consists of a guard time (a period where
no characters are sent to the modem), followed by 3 escape
characters, followed by another guard time. At power up, the guard
time is set to 1 second minimum, and the escape character is set
as +. These two parameters can be modified via registers S12
and S2, respectively.
An alternate attention sequence A/ may be sent which behaves
much like the AT sequence except that it causes the previously
entered command specified with an AT prefix to be executed.
When given, it must be in upper case ASCII. No carriage return is
needed.
The CH2000 will stay off-hook with its carrier on after the escape
sequence is received and it returns an OK status message when
it is ready to accept commands. The CH2000 can be put into data
mode by issuing the command ATO [CR].
THE COMMAND FORMAT
Typical commands consist of three elements: the attention se-
quence, the commands themselves, and a terminating carriage
return.
Table 3. Summary of Result Codes and Their meanings.
AT [commands] [CR].
Where: AT represents attention sequence.
Result
Codes
Status
Messages
Meaning
[commands] represents command strings.
[CR] represents carriage return (ASCII 13 or HEX 0D).
When entering commands to the modem, the backspace charac-
ter-control-H (ASCII 8 or HEX 08) can be used to edit mistakes.
AT and A/ may not be edited however. Multiple commands may
be placed in the command line. A command line may be as long
as 40 characters, excluding the letters AT. By way of example, the
command below instructs the CH2000 to configure itself to not
echo characters when in command mode (E0) and then put itself
in answer mode (A).
0
1
2
3
OK
Command executed
Carrier detected at 300 bps
Ring detected
CONNECT
RING
NO CARRIER
Did not detect carrier
4
5
ERROR
Entry error
CONNECT 1200
Carrier detected at 1200 bps
Off-hook, but no response after
5 seconds
6
NO DIAL TONE
Enter: ATE0A[CR]
7
BUSY
Busy signal detected
AT Command Set.
The available command set is divided into four types of com-
10
CONNECT 2400
Carrier detected at 2400 bps
mands: dial modifiers, basic commands, ampersand and per-
cent commands. Refer to the complete list in Tables 4A, 4B and Table 4A. Dial Modifiers and Functions.
4C, 4D respectively.
Dial Modifers
Function
AT Command Data Rate.
P
Pulse Dial
With the serial interface, the rate is speed sensed for parity and
format.
R
T
Originate Call in Answer Mode
Touch Tone Dial
W
;
@
!
Wait for Dial Tone
Return to Idle State
Wait for Quiet Answer Command
Flash hook
THE STATUS MESSAGES
The CH2000 responds with a status message after each com-
mand is executed. This status message may either be a single
digit followed by a carriage return or a carriage return and line feed
with a message in English, followed by a carriage return and line
feed.
,
Pause
Dial Digits/Characters
0-9
A,B,C,D
The basic status code subsets are enabled with the Xn com-
mand. Where n=0,1,2,3,4 establishes the result codes allowed
1999 Cermetek Microelectronics, Inc.
Document No.607-0002 Rev. D (8/99)
5
Table 4B. CH2000 AT Command Set Summary.
CH2000 AT Set Summary
Table 5. CH2000 Register Summary.
CH2000 Register Summary
Function
Register
Basic Commands Function
S0*
S1
S2
S3
S4
S5
S6
S7
S8
Ring to Answer On
Ring Count
AT
A
A/
*Bn
D
Attention Code
Answer command
Escape Code Character
Carriage Return Character
Line Feed Character
Back Space Character
Wait For Dial Tone
Wait Time for Data Carrier
Pause Time for Comma
Carrier Detect Response Time
Lost Carrier to Hang-up Delay
DTMF Dialing Speed
Escape Code Guard Time
Bit Mapped Options Register
Modem Test Options
Repeat Last Command
Communications Standard Option
Dial Command
Off-Line Character Echo Option
Switch Hook Control Option
Speaker Volume Option
Speaker Control Option
On-Line Command
Pulse Dial
Result Code Display Option
Select an S Register
Write to an S Register
Read an S Register
Result Code Form Option
Result Code Set/Call Progress Option
Escape Code Sequence
Pause
*E
Hn
*Ln
*Mn
On
P
*Qn
Sn
Sn=
Sn?
*Vn
*Xn
+++
,
S9
S10
S11
S12
S14*
S16
S18*
S21*
S22*
S23*
S24
S25*
S27*
S28*
Test Timer
Bit Mapped Options Register
Bit Mapped Options Register
Bit Mapped Options Register
Sleep Mode Inactivity Time
Delay to DTR
?
Returns Last Addressed S Register
Long Space Disconnect Option
On Line Echo character Option
Reset
*Yn
Fn
Z
Bit Mapped Options Register
Bit Mapped Options Register
*=S-Registers stored in NVRAM upon receipt of &W command
AT COMMAND APPLICATIONS
Dialing A Phone Number.
The Dial command takes the form Dn, where n is a string of char-
acters. In the simplest form, n will be only the digits of the phone
number to be dialed.
Table 4C. Ampersand Commands.
Ampersand
Commands
Function
*&Dn
&F
*&Gn
*&Pn
*&Sn
&Tn
&V
*&Wn
*Yn
Data Terminal Ready Option
Load Factory Defaults
Guard Tone Option
Make to Break Ratio Selection
Data Set Ready Option
Test Command Option
View Active Configuration
Store active profile
Example: Dial number.
Enter: AT D1234567
In response to this command, the CH2000 dials the telephone
number 123-4567 and then waits for a carrier from the distant
modem. If no carrier is detected within a given time (the default
time is 30 seconds), the CH2000 automatically releases the line
and sends a NO CARRIER result code. If a carrier is detected, the
CH2000 gives a CONNECT result code and goes on-line, permit-
ting communication with the distant modem.
Recall active profile
Store telephone numbers
Data Carrier Detect Option
*&Zn
*&Cn
*= Commands that can be stored in NVRAM.
The Dial Command may also be issued without a telephone num-
ber. ATD causes the modem to pick up the telephone line without
dialing a number.
Table 4D. Percent Commands.
Pause During Dialing.
Percent
Function
When placing a call from an office with a telephone connected to a
PBX, it may be necessary to dial an access code (usually the digit
9) to get an outside line. Inserting a comma in the telephone
number instructs the modem to pause for a specific length of time.
The factory set default pause time is 2 seconds.
Commands
%Dn
%J
DTMFAttenuation
Load Secondary Factory Defaults
Example: Dial 9, pause, dial number.
Enter: AT DT9, 1234567
NOTE:
A detailed definition of all commands and registers
is available from Cermetek Microelectronics, Inc.
Refer to Cermetek document AT Commands and
S-Registers Reference Guide.
Multiple commas may be used to generate integer multiples of the
specified delay time.
1999 Cermetek Microelectronics, Inc.
Document No. 607-0002 Rev. D (8/99)
6
Originate a Call in Answer Mode.
The D command forces the modem into originate mode. To call
an originate-only modem, dial the number and set the modem to
answer mode via the R (reverse originate). This is done by
entering the R command at the end of the telephone number.
+5V
3
D
G
VN0300L
2
SLEEP
S
+
Redial Last Number.
Use A/, the repeat command, to redial the last telephone number
dialed when a busy signal is received.
1
10 uf
16V
6
220 uf
16V
3
+
7
SPK
5
Return to Command State.
LM386
_
+
0.1 uf
0.01 uf
2
1
The modem can be forced to reenter the command state after
dialing (without hanging up) by ending the dial command with a
semicolon. This is useful when using the modem as an auto
dialer.
8
+
4
Ohm
8
SPEAKER
1K
10 uf
Example: Touch-tone dial 9, pause, dial number, return for
command.
Enter: AT DT9, 1234567;
Result: OK
Figure 5. Speaker Control Circuit--optional to allow for call
progress monitoring.
Automatic Answering.
The S0 register controls the number of rings that must occur
before the modem answers a call. The register may range in
value from 0-255.
PHONE LINE CONNECTION GUIDELINES
S0 = 0
S0 = 1
DO NOTANSWER TELEPHONE
ANSWER ON RING 1
1) The CH2000 must be mounted in the final assembly such
that it is isolated from exposure to any hazardous voltages
within the assembly. Adequate separation and restraint of
cables and cords must be provided.
S0 = 2
S0 = 3
ANSWER ON RING 2
ANSWER ON RING 3
2) The circuitry from the CH2000 to the telephone line interface
must be provided in wiring that carries no other circuitry other
than that specifically allowed in the FCC rules (such as A and
A1 leads).
S0 = 255
ANSWER ON RING 255
When S0 is set to 0, the modem will not auto-answer.
3) Connection to phone line should be made through an RJ-11
jack.
4) PCB traces from the modems RING and TIP pins to the RJ-11
jack must be 0.1 inch spacing or greater to one another and
0.2 inch spacing or greater to all other traces. The traces
should have a nominal width of 0.020 inches or greater.
5) The RING and TIP PCB traces should be as short as possible
and oriented to prevent coupling other high speed or high
frequency signals present on the host circuit PCB.
6) No additional circuitry other than that shown in Figure 6 may
be connected between the modem module and the RJ-11
jack. Doing so will invalidate the FCC approval.
7) The CH2000, the RJ-11 jack, the interfacing circuitry and all
PCB traces in between, must be contained on a PCB with a
94 V-0 flammability rating.
CONNECTING TO THE HOST UART
Since a modem communicates data serially and most host prod-
ucts handle data in a parallel format, a UART is needed to make
parallel-to-serial and serial-to-parallel translations.
The Serial Interface Lines.
The CH2000 supports a full EIA-232D/V.24 serial interface. Signal
levels are TTL rather than EIA-232D level compatible, which al-
lows you to directly connect the modem to your hosts UART with-
out level translating circuitry. See Table 2 for complete pin descrip-
tion.
Two of the following three pins are all that are required for proper
modem operation: TXD, RXD and DTR. The modem is controlled
by sending it serial commands over TXD and can be monitored by
serial status messages returned on RXD. DTR is optionally used
to reset, terminate calls or return CH2000 to command mode.
8) The supplied FCC registration label must be applied visibly
on the outside of the product.
9) The products User Manual must provide the user with in-
structions for connection and use as recommended in Sec-
tion FCC Registration.
All other serial interface lines may be utilized for the convenience
of your application but are not required by the CH2000. Unused
outputs (from modem) should be left unconnected. Unused in-
puts should be set to the proper logic level. See Table 2.
1999 Cermetek Microelectronics, Inc.
Document No.607-0002 Rev. D (8/99)
7
Figure 6. PSTN Line Interface for CH2000 Products.
in the end product and the end product has been delivered to the
end user, the end product must be returned to the end product
supplier where the CH2000 can be removed from the end product
and then forwarded to Cermetek for repair.
CH2000 HANDLING AND ASSEMBLY RECOMMEN-
DATIONS
The CH2000 contains static-sensitive components and should
only be handled by personnel and in areas that are properly pro-
tected against static discharge.
FOR YOUR USERS MANUAL
The Part 68 rules require the following (or equivalent) be provided
to the end user of equipment containing a DAA:
There are two mounting techniques that are recommended for
physically connecting the CH2000 to a PCB: 1) sockets, and 2)
direct soldering.
Type of Service: The (insert end product name) is designed to be
used on standard device telephone lines. It connects to the tele-
phone line by means of a standard jack called the USOC RJ-11C
(or USOC RJ45S). Connection to telephone-company-provided
coin service (central office implemented systems) is prohibited.
Connection to party lines service is subject to state tariffs.
Direct Soldering.
The CH2000 may be wave soldered onto a circuit card. The CH2000
is hermetically sealed and will not be harmed by industry standard
wave soldering processes.
Socketing.
Changes in Attestation Procedure for Plugs and Jacks:
The socketing approach to mounting eliminates cleaning and
desoldering concerns. When the socket is used, it must make a
solid connection to all pins. Failure to do so will cause unreliable
operation. Also, steps should be taken to assure that the module
remains tightly seated in the socket after the end product is shipped.
(Name of applicant) attests that the network interface plugs or
jacks used on this equipment comply with and will continue to
comply with the mechanical requirements specified in Part 68,
Sub-part F, specifically the dimensions, tolerances and metallic
plating requirements. The compliance of these connectors will be
assured by purchase specifications and incoming inspection.
Documentation of such specifications and/or inspections will be
provided by the FCC within 30 days of their request for the same.
FCC REGISTRATION
The CH2000 is registered with the FCC (Federal Communica-
tions Commission) under Part 68. To maintain the validity of the
registration, you must serve notice to the end user of the product of
several restrictions the FCC places on the CH2000 and its use.
The following notice is recommended and should be included in
the end products user manual.
Telephone Company Procedures: The goal of the telephone com-
pany is to provide you with the best service it can. In order to do
this, it may occasionally be necessary for them to make changes
in their equipment, operations or procedures. If these changes
might affect your service or the operation of your equipment, the
telephone company will give you notice, in writing, to allow you to
make any changes necessary to maintain uninterrupted service.
Also, the FCC requires that Cermetek make all repairs to the
CH2000. If repairs are necessary after installation of the CH2000
1999 Cermetek Microelectronics, Inc.
Document No. 607-0002 Rev. D (8/99)
8
Table 6. CH2000 System Data Mode Compatibility Specifications
Parameter
Specification
Parameter
Specification
2400, 1200, 600 bps character
asynchronous. 0-300 bps asynchronous
Receive Carrier Frequencies Originate
2400Hz + 7Hz
1200Hz + 7Hzz
Asynchronous
V.22 bis, V.22, 212A
Answer
Answer 'space' 2020Hz + 7Hz
Answer 'mark' 2225Hz + 7Hz
Original 'space' 1070Hz + 7Hz
Original 'mark' 1270Hz + 7Hz
TXD may differ +1%, -2.5% from modem
output. Offsets will be corrected by
adding/deleting stop bits.
Asynchronous
Speed Range
Bell 103
Asynchronous
Format
Receiver
Sensitivity
OFF to ON threshold-43 dBm
ON to OFF threshold-48 dBm
8, 9, 10 bits, including start, stop, parity
Two-wire full duplex over public switched
network. On-chip hybrid and billing delay
timers.
Telephone Line
Interface
Billing Delay
Hysteresis
2.0 to 3.0 seconds (Ta=25OC)
2 dB minimum
V.22 bis, 16 point QAM at 600 baud. V.22
and 212A, 4 point, DPSK at 600 baud.
103 binary phase coherent FSK.
Modulation
Alternate 'ones' and 'zeros' and error
detector, to be used along with most
loopbacks. A number indicating the bit
errors detected is sent to DTE.
Fixed compromise equalization,
transmit.
Adaptive equalizer for PSK/QAM,
receive.
Self Test
Pattern Generator
Line Equalization
Local analog loopback.
Local digital loopback.
Remote digital loopback.
Request remote digital loopback.
Local interface loopback modem with
self test.
Transmit Carrier
Frequencies
V.22 bis, V.22,
212A
Originate 1200Hz + 0.1%
Diagonostics
Available
Answer
2400Hz + 0.1%
With speaker or quiet screen
messages
Call Progress
Tones Detected
(no dial tone, busy, ring-back, modem
answer tone and voice).
Originate 'space' 1070Hz + .01%
Originate 'mark'
Answer 'space'
Answer 'mark'
1270Hz + .01%
2020Hz + .01%
2225Hz + .01%
Bell 103 mode
Computer Interface
IBM PC/XT/AT bus compatible with an
8250/16450/16550A UART as a serial
controller.
In certain circumstances, it may be necessary for the telephone
company to request information from you concerning the equip-
ment which you have connected to your telephone line. Upon
request of the telephone company, provide the FCC registration
number and the ringer equivalence number (REN); both of these
In the event repairs are ever needed on the (insert your product
name), they should be performed by (insert your company name)
or an authorized representative of (insert your company name).
For information contact: (insert your company address).
should be less than five in order to assure proper service from the
telephone company. In some cases, a sum of five may not be
useable. Consult your local telephone service provider.
If Problems Arise: If any of your telephone equipment is not oper-
ating properly, you should immediately remove it from your tele-
phone line, as it may cause harm to the telephone network. If the
Telephone Company notes a problem, they may temporarily dis-
continue service. When practical, they will notify you in advance of
this disconnection. If advance notice is not feasible, you will be
notified as soon as possible. When you are notified, you will be
given the opportunity to correct the problem and informed of your
right to file a complaint with the FCC. Contact your local telephone
service provider if you have any questions about your phone line.
1999 Cermetek Microelectronics, Inc.
Document No.607-0002 Rev. D (8/99)
9
Table 7. CH2000 Electrical Specifications.
Ta=25OC
Symbol
Characteristic
Min.
Typ. Max.
Units
Vcc
Supply voltage
Supply Current
4.75
5.0
5.25
V
Off hook operating current
On hook operating current
Power down operating current
50
40
16
75
mA
mA
mA
Icc
Output Low Voltage ____ ___ __ ___
(IOL=1.6mA) SLEEP, DSR, DCD, HS, RXD only
(IOL=4mA) V/D
0.4
0.26
---
V
V
VOL
RI (See Note 1)
---
---
---
Output High Voltage ____ ___ __ ___
(IOH=-100uA) SLEEP, DSR, DCD, HS, RXD
(IOH=-4mA) V/D
2.4
4.18
---
V
V
VOH
RI (See Note 1)
---
Input Low Voltage
DTR, TXD
RXD
VIL
0.8
0.95
V
V
Input Leakage Current
TXD, DTR, ______ ____ ____ ___
RXD, RST, SLEEP, DSR, DCD, HS
100
10
uA
uA
I , ILO
IN
Capacitive Load
TXD, DTR, RXD
CP
VIH
10
pF
Input High Voltage
DTR, TXD
RXD
2.4
3.3
V
V
VT+
VT-
RST (Positive Hysteresis Threshold for Reset pin)
RST (Negative Hysteresis Threshold for Reset pin)
2.7
1.6
V
V
Note 1: The RI signal can drive a 74HC14 directly to detect ringing over the US ring voltage range. The CH2000 has an internal 30K Ω pullup
resistor on the RI signal. Adding an external pullup resistor to RI will decrease the ring detect sensitivity at low ring voltages. Use of the RI signal to
detect a ring is not required as the modem can be instructed to automatically answer a ring. If TTL compliance is required when used to activate
external circuitry, Cermetek recommends using a Schmitt Trigger or the Envelope Detect Circuit in Figure 4.
DEFAULT STATUS, PERFORMANCE, AND SPECS
The following is a summary of the Default Configuration Profile installed by Cermetek Microelectronics, Inc., prior to delivery of the
CH2000.
Escape code character = 43
Async mode selected
Carriage return character = 13
2400bps
Bell 212A operation at 1200bps
Line feed character = 10
Even parity
Back space character = 8
Auto answer disabled
Command echo ON
All result codes enabled extended
Wait for dial tone before dialing = 2 seconds
Detects busy signal
Full word result codes
Pulse dial make/break ratio = 39/61
DSR enabled
Duration of wait for dial tone = 2 seconds
Duration of wait for carrier after dialing = 30 seconds
Duration of deal pulse (comma) = 2 seconds
Carrier detect response time = 0.1 seconds
Escape code guard time = 1 second
Length of use after comma = 2.0 seconds
Last carrier to hang up delay = 0.1 seconds
DTMF interdigit delay = 0.1 seconds
Modem enabled DTR
DCD enabled
Speaker enabled but off when receiving carrier
Speaker volume set to medium
Local modem will grant RDL request from remote modem
Guard tones disabled
DTMF Attenuation = -4dB
Sleep mode inactivity time = 5 seconds
Long space disconnect disabled
Minimum DTR pulse width = 0.1 seconds
Ring count = 01
1999 Cermetek Microelectronics, Inc.
Document No. 607-0002 Rev. D (8/99)
10
Table 8. CH2000 Electrical Specifications
Parameter
Minimum Typical Maximum Units
Comments
Ring Voltage Sensitivity
Return Loss @ 1000 Hz
Ring Frequencies
40
VRMS
dB
17
600 ohm
15.3
68
Hz
Transmit Level
-12
dBm
msec
600 ohm - Data Mode
Delay
Command Mode After Reset
200
20
Between all command
characters
Inter Character Delay
msec
Between all AT
commands
Command Delay
100
10
msec
msec
dBV
Minimum Reset Pulse
If user supplied
RXA Transmission Insertion
Loss
Measured from AXT to
Tip/Ring per Figure 3
-1.5
-1.0
3.2
Measured from
Tip/Ring to AXR per
Figure 3
RXA Receiver Insertion Loss
dBV
Vpp
SPK Audio Output with DC
reference of 2.5V+20mV
Measured with 300
ohm, 0.01uF load
Table 9. Other Performance Specifications
Minimum Typical Maximum Units Comments
Parameter
DTMF Twist (Balance)
DTMF Tone Duration
3
dB
ms
pps
%
50
255
20
95 ms default
Pulse Dialing Rate
10
10pps default
Pulse Dialing Make/Break
Pulse Dialing Make/Break
Pulse Interdigit Interval
Call Progress Passband Frequency
Wait Time for Dial Tone
39/61
33/67
US, Canada default
UK, Hong Kong
789 ms default
%
700
120
2
3000
620
ms
Hz
sec
255
Two seconds default
Table 10. Analog Characteristics
Name
Type
O (DF)
Characteristic
Value
SPK
Minimum Load
300 Ω
Maximum Capacitive Load
Output Impedance
Output Voltage
0.01µF
10 Ω
2.5 + 1.6V
<20mV
D.C. Offset
(with reference to 2.5V nominal)
1999 Cermetek Microelectronics, Inc.
Document No.607-0002 Rev. D (8/99)
11
Table 11. Summary of CH2000 Product Family Options.
Model
CH2000
Summary of Features
Operating Temperature
Full Function, NVRAM, FCC Part 68 Approved, Hermetic
0o to 70oC
CH2000ET
Full Function, + Extended Temperature Performance,
NVRAM, FCC Part 68 approved, Hermetic
-40oC to +85oC
Notes: 1. All dimensions are in inches.
2. Case dimensions are nominal + 0.02 inches.
3. Pin length is nominal + 0.03 inches.
4. Cermetek reccomends that 0.040 inch diameter plated through holes are used with 0.060 inch diameter pads.
5. Pin spacings are nominal.
Figure 7. CH2000 Physical Dimensions and Pin Functions.
ermetek
C
microelectronics
.
.
406 TASMAN DRIVE SUNNYVALE, CALIFORNIA 94089 TEL: (408) 752-5000 FAX: (408) 752-5004
E-mail: cermstaf@cermetek.com
Website: www.cermetek.com
Cermetek reserves the right to make changes in specifications at any time and without notice. The information furnished by
Cermetek in this publication is believed to be accurate and reliable. However, no responsibility is assumed by Cermetek for its use,
or for any infringements of patents or other rights of third parties resulting from its use. No license is granted under any patents or
patent rights of Cermetek.
Printed in U.S.A.
Document No. 607-0002 Rev. D (8/99) 12
1999 Cermetek Microelectronics, Inc.
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