Cermetek CH1787 User manual

Cermetek Microelectronics, Inc. Document No. 603-0182 Rev. D (11/98) 1
INTRODUCTION
The CH1787 is a small full function modem that is FCC Part
68 approved. It has been designed to be used in
applications where there is little or no controller intelligence
to command the modem. This allows the user to operate
the modem via hardware resources only, not requiring AT
Command execution for basic operation. For those
applications where there is controller intelligence, the
CH1787 operates like a standard AT Command driver
2400bps, V.22bis asychronous modem.
The CH1787 is ideal as a remote modem such as found in
alarm products and in industrial controllers. Upon some
operational event, the modem will dial a prestored telephone
number under pin activation to make a modem connection
with a host or another site. The modem can also be set to
automatically answer incoming calls or manually answer a
call, using an answering pin. A call can be ended via a
hang-up pin.
GENERAL DESCRIPTION OF FUNCTIONAL
BLOCKS
Figure 1 is a functional block diagram of the CH1787. Each
block will be described. The CH1787 is a highly integrated,
full function modem, comprised of a modulator/demodula-
tor, controller, and an FCC Part 68 approved telephone in-
terface, also called a Data Access Arrangement (DAA) and
NVRAM.
Modulation/Demodulation and Control
This Functional Block is comprised of a monolithic modem
integrated circuit, with built-in facilities to accommodate in-
tegrated AT command control and resident interfaces for
general communication and routing to the DAA.
Controller
The controller is a programed microprocessor that provides
commands to the modem in response to external pin acti-
vation. The following pins are controlled by the micropro-
cessor and are described in detail in Table 1. These pins
are operational when the modem is in use at 2400bps only.
ANS - Manual Answer Pin Input - Answer mode-
Places modem in answer mode
ORG - Manual Originate Pin Input - Originate mode -
places modem in originate mode
ORA- Automatic Dial Pin Input - Dials one of two
prestored numbers based on TST
See pin description Table 1 for more details.
FEATURES
Supports Standards CCITT V.22bis, V.22,
Bell 212, and Bell 103
 FCC Part 68 approved and DOC approvable
 Does not require a microprocessor to operate
 Pin activated hang-up
 Pin activated answer
 Manual originate and answer pins
 AT Command structure available
 1000 VAC isolation barrier
 Single 5 volt operation
 Low power sleep mode
 Automatic adaptive and fixed compromise
equalization
 Test modes and diagnostics
 Size: 2.0 x 1.25 x 0.53
 NVRAM allows storage of custom configurations
and telephone numbers
 Operating temperature 0o-70oC
 Extended temperature -40oC to 85oC order
CH1787ET
CH1787 Small Functional Modem
Cermetek
microelectronics
TST - Steering Pin Input used with ORA to select the user
stored number or Cermetek test number
HNG- Hang-up Pin Input used to terminate an active
modem connected
AAR- Automatic Answer Pin - used to place the modem
in Auto Answer Mode
Figure 1. CH1787 Functional Block Diagram

Cermetek Microelectronics, Inc. Document No. 603-0182 Rev. D (11/98) 2
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. The SPK signal is usually input to
an audio power amplifier and the amplifier drives a speaker coil.
Figure 5 shows how to drive an 8 Ωspeaker.
The speaker can be turned on and off with the ATMn command.
The speaker volume can be adjusted by the ATLn command,
where n is 0, 1, 2, or 3.
Serial Host Interface
The serial interface is V.24 (EIA-232-D) compatible interface. See
pin description.
NVRAM can save up to four telephone numbers with up to 36
digits or modifiers in each telephone number. The AT&Zn=s com-
mand will store s, the telephone number dial string. The ATDTS=n
command will cause the modem to dial one of the four stored
telephone numbers. The NVRAM storage location for the four
telephone numbers is selected by an n of 0, 1, 2, or 3. Location 1
is used for the ORA stored number and Cermetek number.
Supported Features
AT Command Set
A 40-character command line is supported. The command line
starts with AT and may contain standard or enhanced commands.
See Cermetek detailed command summary-
www.cermetek.com.
Phone Control
The CH1787 contains a pin called Voice/Data (V/D). This pin
toggles high when the modem goes off hook and can be used to
activate a relay which can switch a telephone on or off the Tip and
Ring Telco lines. This allows the telephone to be disconnected
when a data call is in progress, preventing the data from being
disturbed by an inadvertent telephone pick-up. See Figure 2.
NVRAM
NVRAM can save up to two user-customized modem configura-
tions. The AT&Wn command will store the active modem con-
figuration in one of two NVRAM locations as selected by an n of 0
or 1. The AT&Yn command selects one of the stored modem
configurations to be automatically recalled and active upon a re-
set or power up. The ATZn command immediately recalls and
activates a stored configuration. See Tables 2 and 3 for storable
S-Registers and Commands.
Figure 2. Voice/Data Port Control
DAA
The CH1787 is designed to meet North American telephone stan-
dards as set by FCC Part 68 and DOC. The telephone line inter-
face is designed to meet 1000VAC and 1500 volt peak surge
isolation, among other parameters. As such, it will meet U.S. and
Canadian requirements and other international requirements that
specify that level of isolation. The CH1787 comes with FCC Part
68 approval, a label is provided with the registration number and
ringer equivalent. This label should be prominently displayed.
As with most countries, except the U.S., Canada requires sub-
mission of the product containing the CH1787 for DOC approval.
This can be done by submitting the design to a test house or
consultant. Call Cermetek for a consultant list.
SLEEP MODE
To minimize the modem power consumption, the CH1787 includes
a power down feature called the Sleep Mode. When activated the
CH1787 will automatically enter the Sleep Mode after 0 to 255
seconds of inactivity. The time of inactivity is selected by the ATS24
command and 5 seconds is the default time. The modem returns
to normal operation when a ring signal is received or is upon an
input low signal on TXD. ATS24 = 255 disables the Sleep Mode
and is the default.
_____
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 modem enters the Sleep
Mode. In the sleep mode, power is reduced by 50% of normal
operating power.
Transmission Speed
The transmission rate of the host computer must be 300, 1200, or
2400 bps. The modem will connect at the selected speed or will
fall back to the speed set by the remote or answering modems
serial interface (the DTE transmission speed). That determines
the originate speed. The modem can be either originating (calling
modem) or answering (remote modem). The following table
shows the speeds:
Originate Mode
Answer Mode 300 1200 2400*
300 300 1200 1200
1200 300 1200 1200
2400 300 1200 2400
*Pin activated operation at 2400bps only. Other speeds may be
used with AT Command operation.
Speed and Parity Selection
Before a call, the modem adjusts to the host speed (2400, 1200, or
300 bps) and parity (odd, even, mark, space, or none) via a host-
initiated training sequence. This also selects the speed of the
data for originate calls. The modem automatically adapts to the
callers speed on answer calls.
The modem matches the hosts parity when it returns status mes-
sages to the host. During a data connection, however, the modem
passes parity through without interpretation or alteration.

Cermetek Microelectronics, Inc. Document No. 603-0182 Rev. D (11/98) 3
POWER SUPPLY
The modem module is a complex sub-system that may be treated
as any other component. Special attention should be paid to the
power supply connections. The modem decodes analog signals
from the telephone line that are in the millivolt range. Al though the
modem is designed to withstand significantly induced power sup-
ply noise, there is a limit. Steps must be taken 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 50 mV peak. If necessary, use dedi-
cated power and ground planes. Failure to provide such operating
conditions could cause the modem to malfunction.
The CH1787requires a single +5V ±5% supply. It is recommended
that by-pass capacitors be placed on the power supply as close to
the modems supply input as practical. It is recommended that a
10 µF Electrolytic capacitor in parallel with a 0.01µF ceramic
capacitor be used.
WARNING: The CH1787 has been FCC Part 68 approved as a
data modem. Utilization of the Voice/Tone Port requires further
registration. FCC will require that the system, including the CH1787
and the handset or DTMF transceiver, adhere to Part 68 rules.
MODEM CONTROL
The CH1787 modem may be controlled by sending serial ASCII
command sequences. The commands are sent to the modem
serially on TXD. After execution of the command, the modem re-
turns a serial status message on RXD, to indicate the completion
status of the command.
Initializing the Modem
Before commands may be sent to the modem, the modem must
be initialized. This consists of two events: 1) after power-up, a
hardware reset pulse must be applied to the modem, and 2) the
modem must be trained to the hosts speed (2400, 1200, 300bps)
and parity (odd, even, mark, space or none).
Figure 4. CH1787 Application Diagram of Test Circuit
Figure 3. Voice/Tone Injection
+Vcc
ISOLATED
ENVELOPE
RING DETECT
4.7uF
Vcc
4.7K
22K
10K
10K
+
+LM393
LM393
1
2
3
45
6
7
8
+
+
.1uF
RI
FROM 1787
PIN 12
+Vcc
Power-up Reset
After applying power to the modem, an internally generated reset
pulse is created. The user can also reset the modem externally by
applying the high-going reset pulse to RST for at least 10ms after
the +5V power supply has stabilized. Delay sending commands
to CH1787 for 100-200ms.
The modem must be trained to match the hosts 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. The modem is trained by sending it the following three-
character sequence.
Training the Modem
1
2
7
8
9
10
11
12
13
14
15
16
17
18
19
RING
TIP
RXA
DTR
ANS
V/D
RST
RI
CTS
DSR
DRA
TXD
DIR
IRQ
SLEEP
CH1787
34
33
32
31
30
29
28
27
26
25
24
23
22
21
20
AAR
GND
VCC
RXD
HNG
CON
TST
SPKR
NC
NC
NC
DAG
HS
DCD
GND
ENABLE RXA 4.7K
2N2222 1N914
+5V
AB 499
1
4
3
2
+15V
20K
20K
TL064
82K
20K
0.1uF
0.1uF
0.1uF
0.1uF
0.1uF
2.2uF
nonpolar
63.4K
20K
A1 54K
76
11
28K
A2
5
TL064
MECHANICAL RELAY ONLY.
A ZERO IMPEDANCE SWITCH MAY REPLACE
THE RELAY AND TRANSISTOR CIRCUIT.
ADJUST A2 FOR THE DESIRED LEVEL OF AXT VOICE TO BE ECHOED TO AXR.
DECREASE RECEIVE GAIN SIGNAL. AXR. BY DECREASING VALUE OF A1.
-
+
+
-
VOICE OR DTMF
SIGNAL

Cermetek Microelectronics, Inc. Document No. 603-0182 Rev. D (11/98) 4
Table 1. CH1787 Pin Descriptions
Note: (1) If VCC has a slow power up ramp time, the internal reset may be ineffective.
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.42Sotni552gnidaolybenodsisihT.detibihni

Cermetek Microelectronics, Inc. Document No. 603-0182 Rev. D (11/98) 5
Spare pins are available for custom functions. Contact Cermetek with your requirements.
NIPEMANO/INOITCNUF
02DNGI
.DNUORG
12 ____
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.1

Cermetek Microelectronics, Inc. Document No. 603-0182 Rev. D (11/98) 6
Modem States
The modem can be in either a command state or a data mode
state. When the modem is idle, it is in the command state. When
a data call is in progress, it is in the data mode state. The modem
does not recognize commands when in the data state. To recog-
nize commands, the computer must send an escape sequence
to the modem that forces it out of the data mode and into the
command mode.
The escape sequence consists of a guard time (a period where
no characters are sent to the modem) followed by 3 escape char-
acters, followed by a guard time again. At powerup, the guard
time is set to 1 second minimum, and the escape character is set
as +. These two parameters can be modified via registers S2
and S12.
The modem will stay off-hook with its carrier on after the escape
sequence is received. It returns an OK status message when it is
ready to accept commands. You may re-enter the data mode by
issuing the ONLINE command ATO [enter].
AT[CR]
Where: A and T must be upper case or lower case
[CR] repesents carriage return
The modem will respond with one of the following status mes-
sages, depending on whether it is optioned for abbreviated or
English status messages.
0[CR] (Abbreviated form)
[CR][LF][OK][CR][LF] (English form)
Where: [CR] represents carriage return (ASCII 13)
[LF] represents line feed (ASCII 13)
The modem may be retrained any time while it is idle.
Another attention sequence A/ is much like the AT sequence
except it repeats the previously entered command specified with
an AT prefix. When given, it must also be in upper case ASCII.
No carriage return is needed.

Cermetek Microelectronics, Inc. Document No. 603-0182 Rev. D (11/98) 7
Table 2 Ch1787 Register Summary
Register Function
S0* Ring to Answer On
S1 Ring Count
S2 Escape Code Character
S3 Carriage Return Character
S4 Line Feed Character
S5 Back Space Character
S6 Wait For Dial Tone
S7 Wait Time for Data Carrier
S8 Pause Time for Comma
S9 Carrier Detect Response Time
S10 Lost Carrier to Hang-up Delay
S11 DTMF Dialing Speed
S12 Escape Code Guard Time
S14* Bit Mapped Options Register
S16 Modem Test Options
S18* Test Timer
S21* Bit Mapped Options Register
S22* Bit Mapped Options Register
S23* Bit Mapped Options Register
S24 Sleep Mode Inactivity Time
S25* Delay to DTR
S27* Bit Mapped Options Register
S28* Bit Mapped Options Register
*=S-Registers stored in NVRAM upon receipt of &W command
Ampersand Commands Function
*&Dn Data Terminal Ready Option
&F Load Factory Defaults
*&Gn Guard Tone Option
*&Pn Make to Break Ratio Selection
*&Sn Data Set Ready Option
&Tn Test Command Option
&V View Active Configuration
*&Wn Store active profile
*Yn Recall active profile
*&Zn Store telephone numbers
*&Cn Not supported
Percent Commands Function
%Dn DTMF Attenuation
%J Load Secondary Factory Defaults
NOTE: A detailed definition of all commands and registers is available from
Cermetek Microelectronics, Inc.
*= Commands that can be stored in NVRAM.
Table 3 Ch1787 AT Command Set Summary
Basic Commands Function
AT Attention Code
A Answer command
A/ Repeat Last Command
*Bn Communications Standard Option
D Dial Command
*E Off-Line Character Echo Option
Hn Switch Hook Control Option
*Ln Speaker Volume Option
*Mn Speaker Control Option
On On-Line Command
P Pulse Dial
*Qn Result Code Display Option
Sn Select an S Register
Sn= Write to an S Register
Sn? Read an S Register
*Vn Result Code Form Option
*Xn Result Code Set/Call Progress Option
+++ Escape Code Sequence
, Pause
? Returns Last Addressed S Register
*Yn Long Space Disconnect Option
Fn On Line Echo character Option
Z Reset
AT COMMAND APPLICATIONS
Pause ,
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 commands the modem to pause for a specific length of
time. A factory default pause time is 2 seconds.
Example: Dial 9, pause, dial number.
Enter AT DT9, 1234567
Multiple commas may be used for a greater delay time.
TOUCH TONE AND PULSE DIALING T and P
The modem can use DTMF (touch-tones) or dial pulses when
dialing a telephone number. If the dial command does not specify
which type to use, the modern defaults to the type last specified.
The power-on default value is P.
Example: Pulse dial 9, pause, touch-tone dial number.
Enter: AT DP9, T1234567
Originate a Call in Answer Mode R
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). Enter the R
command at the end of the telephone number.
Redial Last Number A/
Use A/, the repeat command, to redial the last telephone
number dialed when a busy signal is received.

Cermetek Microelectronics, Inc. Document No. 603-0182 Rev. D (11/98) 8
Phone Line Connection Guidelines
1) The mounting of the CH1787 in the final assembly must be
made so that it is isolated from exposure to any hazardous
voltages within the assembly. Adequate separation and re-
straint of cables and cords must be provided.
2) The circuitry from the CH1787 to the telephone line interface
must be provided in wiring that carries no other circuitry than
that specifically allowed in the rules (such as A and A1 leads).
Figure 5. Speaker Control Circuit--optional to allow for call
progress monitoring.
Return to Command State ;
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.
Example: Touch-tone dial 9, pause, dial number, return for
command.
Enter: AT DT9, 1234567;
Result: OK
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
S0 DO NOT ANSWER TELEPHONE
S1 ANSWER ON RING 1
S2 ANSWER ON RING 2
S3 ANSWER ON RING 3
DIAL A NUMBER D
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.
Example: Dial number.
Enter: AT D1234567
In response to this command, the modem dials the telephone
number 123-4567 and then waits for carrier from a distant mo-
dem. If no carrier is detected within a given time (the default time
is 30 seconds), the modem automatically releases the line and
sends a NO CARRIER result code. If carrier is detected, the mo-
dem gives a CONNECT result code and goes on-line, permitting
communication with the distant modem.
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.
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.
S0=255 ANSWER ON RING 255
When S0 is set to 0, the modem will not auto-answer.
Example: Assign the value 6 to S0 to set the modem to answer
on the sixth ring.
Enter: AT S0=6
Result: OK
The Serial Interface Lines
The module supports a full RS-232C/V.24 serial interface. Signal
levels are TTL rather than RS-232C level compatible, which al-
lows you to directly connect the modem to your hosts UART with-
out level translating circuitry. A complete description of each signal
follows under Pin Description.
Two of these lines are all that are required for proper modem
operation: TXD, RXD and DTR. The modem is controlled by send-
ing it serial commands over TXD and can be monitored by serial
status messages returned on RXD.
All other serial interface lines may be utilized for the convenience
of your application but are not required by the modem. Unused
outputs (from modem) should be left unconnected. Unused in-
puts should be tied to the proper logic level. See pin description.
3) Connection to phone line should be made through an RJ-11
jack.
4) Traces from the modems RING and TIP pins to the RJ-11
jack must exceed 0.1 inch spacing to one another and 0.2
inch spacing to all other traces. The traces should have a
nominal width of 0.020 inches or greater.
5) The RING and TIP traces should be as short as possible and
oriented to prevent coupling other high speed or high frequency
signals onto the host circuit card.
6) No additional circuitry other than that shown in the following
Figure may be connected between the modem module and
the RJ-11 jack.
7) The CH1787, the RJ-11 jack, the interfacing circuitry and traces
in between, must be mounted on a circuit board with a 94 V-0
flammability rating.

Cermetek Microelectronics, Inc. Document No. 603-0182 Rev. D (11/98) 9
8) The supplied FCC registration label must be applied visibly
on the outside of the host product.
9) The host products User Manual must provide the user with
instructions for connection and use as recommended in Sec-
tion FCC Registration.
MOUNTING THE MODEM
The modem contains static-sensitive devices and should only be
handled by personnel and in areas that are properly protected
against static discharge.
There are two mounting techniques that are recommended for
physically connecting the modem to your circuit card; 1) sockets,
and 2) direct soldering.
The modem may be wave soldered on a circuit card. This part is
hermetically sealed for normal wave soldering process.
The socketing approach to mounting eliminates cleaning and
desoldering concerns. When the socket is used, it must make a
solid connection to all modem pins. Failure to do so will cause
unreliable modem operation. Also, steps should be taken to as-
sure that the module remains tightly seated in the socket after the
host product is shipped.
FCC REGISTRATION
The CH1787 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
that contains the modem of several restrictions the FCC places on
the modem and its use. The following notice is recommended
and should be included in the host products USER MANUAL.
Also, the FCC requires that Cermetek make all repairs to the mo-
dem. If repair is necessary after the modem is installed in your
product and has been delivered to your customer, the modem
must be returned to you where it can be removed from the host
product and then forwarded to Cermetek for repair.
Changes in Attestation Procedure for Plugs and Jacks
(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.
FOR YOUR USERS MANUAL
The Part 68 rules require the following or the equivalent informa-
tion be provided to the end user of equipment containing a DAA:
Type of Service: The (insert your 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 FJ45S). Connection to telephone-company-provided
coin service (central office implemented systems) is prohibited.
Connection to party lines service is subject to state tariffs.
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.

Cermetek Microelectronics, Inc. Document No. 603-0182 Rev. D (11/98) 10
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Table 4. CH1787 System Data Mode Compatibility Specifications

Cermetek Microelectronics, Inc. Document No. 603-0182 Rev. D (11/98) 11
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 telephone
company if you have any questions about your phone line.
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).
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
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
Minimum DTR pulse width = 0.1 seconds
Ring count  01 (CH1786)
Escape code character = 43
Carriage return character = 13
Line feed character = 10
Back space character = 08
Duration of wait for dial tone = 02 seconds
Duration of wait for carrier after dialing = 30 seconds
Duration of deal pulse (comma) = 02 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
DTMF Attenuation = -4dB
Sleep mode inactivity time = 5 seconds
Long space disconnect disabled
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
items are listed on the equipment label. The sum of II of the RENs
on your telephone lines 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 on a given line.
Table 5. CH1787 Electrical Specifications
DEFAULT STATUS, PERFORMANCE, AND SPECS
Ta=25OC
Default Configuration Profile
Async mode selected
2400bps
Bell 212A operation at 1200bps
Even parity
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Cermetek Microelectronics, Inc. Document No. 603-0182 Rev. D (11/98) 12
Table 7. Other Performance Specifications
Table 6. CH1787 Electrical Specifications

Cermetek Microelectronics, Inc. Document No. 603-0182 Rev. D (11/98) 13
Table 8. Temperature Options
Model Operating Temperature
CH1787
CH1787ET
0oC to +70oC
-40oC to +85oC
Figure 7. CH1787 Physical Dimensions and Pin Functions
Cermetek
microelectronics
406 TASMAN DRIVE .SUNNYVALE, CALIFORNIA 94089 . TEL: [phone] FAX: [phone]
E-mail: [email protected]
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.
1998 Cermetek Microelectronics Printed in U.S.A.