CMX602B Consumer Microcircuits Limited, CMX602B Datasheet - Page 7

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

Calling Line Identifier
1.5
1.5.1
The CMX602B's operating mode and the source of the DET and IRQN outputs are determined by the logic
levels applied to the MODE and ZP input pins:
In the 'Zero-Power' modes, power is removed from all of the internal circuitry except for the Ring or Line
Polarity Reversal Detector and the DET and IRQN outputs.
1.5.2
This amplifier is used to convert the balanced FSK and Tone Alert signals received over the telephone line
to an unbalanced signal of the correct amplitude for the FSK receiver and Tone Alert Detector circuits.
The design equations for this circuit are;
The target differential voltage gain depends on the expected signal levels between the A and B wires and
the CMX602B's internal threshold levels, which are proportional to the supply voltage.
 2003 CML Microsystems Plc
General Description
Mode Control Logic
Input Signal Amplifier
ZP
0
0
1
1
Differential voltage gain V AOP / V(b-a) = R8/R6
R6 = R7 = 470k
R10 = 160k
R9 = R8 x R10 / (R8 - R10)
[1] If enabled.
MODE
Figure 3a : Input Signal Amplifier, balanced input configuration
0
1
0
1
Tone Alert Detect
FSK Receive
'Zero-Power'
'Zero-Power'
Mode
Tone Alert Signal
Detection
FSK Level Detector
Ring or Line Polarity
Reversal Detector.
Ring or Line Polarity
Reversal Detector.
7
DET o/p from
Valid ‘off-hook’ CAS.
Ring or Line Polarity
Reversal Detector.
FSK Data Retiming [1] .
Ring or Line Polarity
Reversal Detector.
Ring or Line Polarity
Reversal Detector.
IRQN o/p from
-
CMX602B
D/602B/2