CMX865D2 CML Microcircuits, CMX865D2 Datasheet - Page 5

• Manufacturer Part Number: CMX865D2
• Description: FSK Modem and DTMF Codec
• Manufacturer: CML Microcircuits

FSK Modem and DTMF Codec
4.
This device is capable of detecting and decoding small amplitude signals. To achieve this, V
should be decoupled and the receive path protected from extraneous in-band signals. It is recommended
that the printed circuit board is laid out with a V
impedance connection between the V
connections to the Xtal oscillator capacitors C1 and C2 should also be low impedance and preferably be
part of the V
For best results, an Xtal oscillator design should drive the clock inverter input with signal levels of at least
40% of V
oscillator design assistance, please consult your Xtal manufacturer.
© 2005 CML Microsystems Plc
Notes:
External Components
I/P
O/P
BI
T/S
NC
DD
SS
peak-to-peak. Tuning-fork Xtals generally cannot meet this requirement. To obtain Xtal
Figure 2 Recommended External Components for a Typical Application
ground plane to ensure reliable start up of the oscillator.
R1
X1
=
=
=
=
=
Resistors ±5%, capacitors ±20% unless otherwise stated.
Input
Output
Bidirectional
3-state Output
No Connection
68kΩ
11.0592MHz
or 12.288MHz
SS
pins and the V
SS
5
ground plane in the CMX865 area to provide a low
DD
and V
C1, C2
C3, C4
C5
BIAS
decoupling capacitors. The V
22pF
100nF
10uF
DD
and V
CMX865
D/865/3
BIAS
SS