V23 / Bell 202 Modem
CMX624
CMX624
D2/D5/P4
Signal
Description
Pin No.
16
Name
Type
I/P
RXN
RXO
RT
The inverting input to the Rx input amplifier.
The output of the Rx input amplifier.
O/P
BI
17
18
Open drain output and Schmitt trigger input
forming part of the Ring Signal detector.
RD
I/P
NC
NC
NC
19
20
21
22
Schmitt trigger input to the Ring Signal Detector.
No connection should be made to this pin.
No connection should be made to this pin.
-
-
-
No connection should be made to this pin if the
printed circuit board is to be used for CMX624
only. If the board is also to be used for
CMX644A, a capacitor should be connected as
shown in Figure 2.
-
I/P
No connection should be made to this pin if the
printed circuit board is to be used for CMX624
only. If the board is also to be used for
CMX644A, a capacitor should be connected as
shown in Figure 2.
23
V
Power
24
The positive supply rail. Levels and thresholds
within the device are proportional to this voltage.
DD
Should be decoupled to V by a capacitor
SS
mounted close to the device pins.
Notes:
I/P
O/P
BI
T/S
NC
=
=
=
=
=
Input
Output
Bidirectional
3-state Output
No Connection
This device is capable of detecting and decoding small amplitude signals. To achieve this V and V
DD
BIAS
decoupling and protecting the receive path from extraneous in-band signals are very important. It is
recommended that the printed circuit board is laid out with a ground plane in the CMX624 area to provide
a low impedance connection between the V pin and the V and V
decoupling capacitors.
SS
BIAS
DD
2003 CML Microsystems Plc
5
D/624/7
CMLMICRO [ CML MICROCIRCUITS ]
