Xerox WorkCentre Pro 412, Service Manual

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Circuit Description
WorkCentre Pro 412
Launch Issue
5-2
August 2001
5-2 Circuit Operation
5-2-1 Clock
1) System Clock
Device
Oscillator
Frequency 20MHz
• KS32C61200 RISC PROCESSOR: drives PLL internally and uses 60MHz.
2) Video Clock
Device
Oscillator
Frequency 45.3928 MHz
• Fvd = ((PAPER 1SCAN LINE sending time * SCAN effective late /1SCAN LINE DOT #)*4
=(600dpi*600dpi*58.208mm/s*216mm*4)/(25.4mm*25.4mm*76.1%) = 28.697MHz.
•PAPER 1SCAN LINE sending time = SCAN LINE interval/DOCUMENT SPEED (58.208mm/S)
•1SCAN LINE DOT # = MAZ SCAN distance (216mm) *DOT # per 1mm.
3)USB Clock
Device
Oscillator
Frequency 48MHz
5-2-2 Power on/off Reset
1) Signal Operation
Input Signal
+5V Power Line (VCC)
Output Signal KS32C61200 nRESET 29F800B nRESET
• Power on/off detect VCC RISING/FALLING 4.5°¦4.6V
Reset time (Td) 1.48 to1.52ms
• Td = (Ct*V sensing)/I charge (...Ct = 33µF, Is = 100µA)
2) Timing Chart
and SENSE
VCC
Threahold Voltage
VCC
3.6V
RESET
td
Output
Undefined
Output
Undefined
VCC 2V
td