CH1788 Cermetek Microelectronics, CH1788 Datasheet - Page 5

• Manufacturer Part Number: CH1788
• Manufacturer: Cermetek Microelectronics

Specifications of CH1788

• Lead Free Status / RoHS Status: Supplier Unconfirmed

Cermetek Microelectronics, Inc.
Figure 2. CH1788 Pin Configuration. See Table 2 for detailed Pin Descriptions.
2006 Cermetek Microelectronics, Inc.
NOTE:
PIN
1
2
3
4
5
6
7
Used for LIU/911/Audio Control
Used for LIU/911/General IO
NAME
1. All unused pins should be left unconnected when not required in a specific application,
2. See DC characteristics before attempting to drive an LED directly from the output of any pin.
DSR
DCD
RTS
CTS
Optional High Reset Input
OH
A1
RI
unless specifically directed otherwise.
Used for LIU/Detection
TYPE
O
O
O
O
O
O
I
DTE Signal
DTE Signal
DTE Signal
DTE Signal
DTE Signal
DTE Signal
DTE Signal
Optional Input. Active high. Used when implementing the 911 Priority Pick-Up
circuit or the Line In Use circuit.
Off-Hook. Active low. OH Indicates when the CH1788 is Off-Hook. Used in Line
In Use, 911 Priority Pick-Up applications and for Audio Control.
Request To Send. Active low. Used for optional flow control. Used in conjunction
with the Clear to Send (CTS) pin as a handshaking signal. See the details of
register S90.
Ring Indication. Active low. For each occurrence of a valid ring signal, this pin will
pulse low for 70 ms. This output signal follows the frequency of the ringing signal
and is typically in the 20 to 40 Hz range with a cadence of 2 seconds on with 4
seconds off.
Clear to send. Active low. Used for optional flow control. Used in conjunction with
the Request To Send (RTS) pin as a handshaking signal.
Data Set Ready.
modem is in progress and/or the carrier of the remote modem has been detected
and a valid connection is imminent as measured by DCD being active. This feature
is enabled with the N command.
Data Carrier Detect. Active low. This output must be enabled with the ATC1
command. When enabled, it will become active when both the originated and
answering modems are connected and a data carrier has been detected.
Table 2.
10
11
1
2
3
4
5
6
7
8
9
RST
OH
RI
CTS
DSR
DCD
DTR
A2
TXD
A1
RTS
CH1788 Pin Descriptions.
Active low. A low indicates that handshaking with the remote
CH1788
Top View
Page 5
RING
GND
RXD
V
FUNCTION
TIP
CC
V+
S2
S1
V-
15
14
12
13
22
21
20
19
18
CH1788 Surface Mount PLCC 2400bps Modem
High Voltage Section
Optional S1/S2 Audio
Monitor/Tone/Voice
V+/V- Optional
CID Input
Telephone Line
Input
DTE Signal
Power Input +5V
Document No. 607-0018 Revision A6 (01/06)