Dell 1600n - Multifunction Laser Printer B/W Service Manual page 154

Circuit Diagram
1) Line Interface Signal of Tel Line and LSD is Analog Signal.
2) there is A/D, D/A Converter in LSD, so Analog Signal from Tel Line is transited in Digital through A/D Converter
in DAA and transfer to SSD by DIB Capacitor Digital Signal from SSD is converted to Analog by D/A Converter
in DAA and transfer to Tel Line
CX82500(SFM336)
DSP
3) Transformer transfer Clock from SSD to LSD and Clock Frequency is 4.032MHz. LSD fullwave rectifies Clock to
use as inner Power supply and also use as Main Clock for DIB Protocol Sycn between LSD and SSD.
Transformer transfer Clock by separatin Primary and Secondary, and amplifies Clock Level to LSD by Coil
Turns Ratio 1:1.16.
11.2.1.3 Clock
SSD
- Clock is supplied by transformer from SSD to LSD, and There is PWROUT to adjust output impedance of
Clock Out Driver is inside SSD and CLKSHIGH Registor to adjust duty of HLPWR Registor and Clcok. Clock
from SSD to LSD has Differential structure of 180 phase difference for Noise Robustness DIB Data transfer
Data From SSD to LSD By Capacitor, and also transfer specific data from LSD to SSD. after transfering data
to SSD, RSP is transfered and LSD recognize RSP and change LSD to output Driver transfer Data to SSD.
DIB Data form SSD to LSD by Capacitor has Differential structure of 180 phase difference between DIBP and
DIBN for Noise Robustness
Service Manual
11-6
Transformer
SSD
System
Side
Device
Capacitor
CLKP
CLKN
DIBP
DIBN
CX20493
LSD
Line
Side
Device
Primary Parts
LSD
Tel Line
Ext Line