FX602 Consumer Microcircuits Limited, FX602 Datasheet - Page 7

• Manufacturer Part Number: FX602
• Description: Calling Line Identifier
• Manufacturer: Consumer Microcircuits Limited

Calling Line Identifier
1.5
1.5.1
The FX602'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
FX602's internal threshold levels, which are proportional to the supply voltage.
The FX602 has been designed to meet the applicable specifications with R8 = 470k
rising to 680k
section 1.4 and Fig 3c.
1998 Consumer Microcircuits Limited
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)
at V
[1] If enabled.
MODE
0
1
0
1
DD
Figure 3a : Input Signal Amplifier, balanced input configuration
= 5.0V, and R9 should be 240k
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
at V
DD
= 3.3V and 200k
End of Tone Alert Signal.
Ring or Line Polarity
Reversal Detector.
FSK Data Retiming [1] .
Ring or Line Polarity
Reversal Detector.
Ring or Line Polarity
Reversal Detector.
at V
IRQN o/p from
at V
DD
= 5.0V as shown in
DD
-
= 3.3V nominal,
D/602/7
FX602