CMX602BD4 MX-COM, Inc., CMX602BD4 Datasheet - Page 6

• Manufacturer Part Number: CMX602BD4
• Description: Calling line identifier plus call waiting
• Manufacturer: MX-COM, Inc.

Calling Line Identifier plus Call Waiting (Type II)
4. General Description
4.1 Mode Control Logic
The CMX602B's operating mode and the source of the DET and IRQ 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 IRQ outputs.
4.2 Input Signal Amplifier
The Input Signal 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 A and B input signal levels and the CMX602B's
internal overload and threshold levels, which are proportional to the supply voltage.
The CMX602B has been designed to meet the applicable specifications when R8 = 430k at V
nominal, rising to 680k at V
V
4800 Bethania Station Road, Winston-Salem, NC 27105-1201, USA
ZP
DD
2000 MX-COM, Inc
0
0
1
1
= 5.0V as indicated in Section 3 and as shown in Figure 5. Reference Notes found in Section 3.
MODE
0
1
0
1
Tone Alert Detect
FSK Receive
Zero-Power
Zero-Power
Differential Voltage Gain V
A
B
Figure 3: Input Signal Amplifier, balanced input configuration
Mode
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DD
= 5.0V (see note) and R9 = 240k at V
C6
C7
R6 = R7 = 470k
Tone Alert Signal Detection
FSK Level Detector
Ring or Line Polarity
Reversal Detector
Ring or Line Polarity
Reversal Detector
R6
R7 R9
DET output from
R10
R8
AMPOUT
AMPOUT
V
(B-A)
V
IN+
6
IN-
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SS
=
R
R
8
6
Input Signal Amplifier
+
-
Valid 'off-hook' CAS Duration.
Ring or Line Polarity Reversal Detector
FSK Data Retiming (if enabled). Ring or
Line Polarity Reversal Detector.
Ring or Line Polarity Reversal Detector.
None
DD
R10 = 160k
R9 = R8
= 3.0V dropping to 200k at
CMX602B PRELIMINARY INFORMATION
(R8 - R10)
IRQ output from
V
BIAS
R10
C9
Doc. # 20480204.002
DD
= 3.0V