Cermetek Microelectronics, Inc.
High Speed Modem and FAX Family
2003 Cermetek Microelectronics, Inc.
Page 17
Document No. 607-0003 Revision K3 (09/03)
Table 8. HS Modem Electrical Specifications.
Symbol Characteristic Min.
Typ.
Max.
Units
V
CC
Positive Supply Voltage
4.5
5.0
5.5
V
I
CC
Off Hook
(CH1794)
Nominal Operating Current @
V
CC
= 5.5V when modem is Off Hook
115.0 mA
I
CC
Off Hook
(CH1799)
Nominal Operating Current @
V
CC
= 5.5V when modem is Off Hook
185.0 mA
V
IH
High Level Input Voltage*
2.0
V
V
IL
Low Level Input Voltage*
0.8
V
VT+
Positive Hysteresis Threshold for RESET Pin
2.5
V
VT-
Negative Hysteresis Threshold for RESET Pin
0.5
V
V
OH
High Level Output (I
OH
= 0.5 mA)*
2.4
V
V
OL
Low Level Output (I
OL
= 1.6 mA)*
0.6
V
I
IN
Input Leakage Current (TXD, DTR, RTS)
100
µ
A
I
OH
Input Current (RST)
500
µ
A
C
p
Capacitive Load (TXD, DTR, RTS)
Capacitive Load (RST)
10
8
pF
pF
Test conditions: VCC = 5V ± 10%, Temp = 0°C to 70°F (unless otherwise stated).
*Output Load = 50 pF ± one TTL.
Table 9. HS Modem Electrical Specifications.
Parameter Min.
Typ.
Max.
Units
Comments
Off Hook Impedance
20
Ohm
Trans Hybrid Loss
25
dB
600 Ohm, RXA, TXA
Ring Voltage Loop
110V
250V
V
PP
On 48VDC line voltage for sustained
periods
Line Loop Current – (Off
Hook)
20
100
mA
Does not apply to CH1799LL
Return loss @ 1000 Hz
15
dB
600 Ohm
Ring Frequencies
40
Hz
Receiver Insertion Gain
-0.5
0.0
+0.5
dB
Transmit Power
-9.5
dBm
600 Ohm – Data Mode
First Character After Reset
1.0
sec
Delay
Inter Character Delay
20
50
msec
Between all command characters
Command Delay
100
200
msec
Between all AT command characters*
Minimum Reset Pulse
Duration
10
msec
If user supplied
* Note: Must wait for modem response before issuing new command.
