CMX602B Consumer Microcircuits Limited, CMX602B Datasheet - Page 8

• Manufacturer Part Number: CMX602B
• Description: Calling Line Identifier Plus Call Waiting Type ii
• Manufacturer: Consumer Microcircuits Limited

Calling Line Identifier
The CMX602B has been designed to meet the applicable specifications with R8 = 430k
nominal, rising to 680k
as shown in section 1.4 and Fig 3c.
The Input Signal Amplifier may also be used with an unbalanced signal source as shown in Figure 3b. The
values of R6 and R8 are as for the balanced input case.
1.5.3
Is used to attenuate out of band noise and interfering signals which might otherwise reach the FSK
Demodulator, Tone Alert Detector and Level Detector circuits. The characteristics of this filter differ in FSK
and Tone Alert modes. Most of the filtering is provided by Switched Capacitor stages clocked at 57.7kHz.
1.5.4
This block operates by measuring the level of the signal at the output of the Bandpass Filter, and
comparing it against a threshold which depends on whether FSK Receive or Tone Alert Detect mode has
been selected.
In Tone Alert Detect mode the output of the Level Detector block provides an input to the Tone Alert Signal
Detector.
 2003 CML Microsystems Plc
Bandpass Filter
Level Detector
Figure 3c : Input Signal Amplifier, optimum values of R8 and R9 vs V
Figure 3b : Input Signal Amplifier, unbalanced input configuration
at V
DD
1000
900
800
700
600
500
400
300
200
100
= 5.0V, and R9 should be 240k
0
3
3.5
Nominal V
R8
8
4
DD
R9
4.5
at V
DD
= 3.0V and 200k
5
DD
at V
at V
DD
DD
CMX602B
D/602B/2
= 3.0V
= 5.0V