Epson S1C63558 - Manual (Page 147)

S1C63558 TECHNICAL MANUAL EPSON 137
CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (FSK Demodulator)
Band-pass
filter
Carrier
detection circuit
Reference voltage
generation circuit
TIP
Amp
–
+
AV SS
AV DD
FSKIN
CDET
RDET
FOSC3
PWDN
RDIN
RING
FB
0.1
µ
F
RDRC
V REF
V DD
BPOUT
CDIN
FSK
demodulator
Clock
generator
Fig. 4.15.1.2 FSK core configuration
The external terminals of the FSK demodulator are as follows:
AV DD , AV SS Power terminals for the FSK block. Supply power respectively as AV DD = V DD , AV SS = V SS .
TIP Inverted input terminal of the input amplifier
RING Non-inverted input terminal of the input amplifier
FB Feedback output terminal of the input amplifier
BPOUT Output terminal of the band-pass filter
CDIN Input terminal for carrier signal detection
RDIN Input terminal for ring signal detection
RDRC I/O terminal for connecting an RC network
V RFF Reference voltage (1/2V DD ) output terminal
The basic external connection diagram is shown in Figure 4.15.1.3.
TIP
RING
FB
TIP
RING
RDIN
BPOUT
CDIN
RDRC
Protection
Network
0.2
µ
F 0.2
µ
F
470k
33k
10k 1000pF
1000pF
0.2 µ F
0.1
µ
F
270k
10k
V REF
AV DD
V DD
AV SS
V SS
0.1 µ F
V DD
Fig. 4.15.1.3 Basic external connection diagram (example for Bellcore)