Samsung SF-830 Service Manual page 121

CIRCUIT DESCRIPTION
3-2 Circuit Operation
3-2-1 CLOCK
1) System Clock
2) Video Clock
3)USB Clock
4)PM-22 Clock
3-2-2 POWER ON/OFF RESET
1) Signal Operation
2) TIMING CHART
Threahold Voltage
V
Repair Manual
3-2
Device
Frequency
• KS32C61200 RISC PROCESSOR: drives PLL internally and uses 60MHz.
Device
Frequency
• 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
Device
Frequency
Device
Frequency
Input Signal
Output Signal
• POWER ON/OFF DETECT
RESET TIME (Td)
• Td=(Ct*V sensing)/I charge (...Ct=33µF, Is=100µA)
V and SENSE
CC
V
3.6V
CC CC
t
RESET d
Output
Undefined
Oscillator
20 MHz±%
Oscillator
45.3928 MHz±%
Oscillator
48 MHz±%
Oscillator
66 MHz±%
+5V Power Line (VCC)
KS32C61200 nRESET 29F800B nRESET
VCC RISING/FALLING 4.5°≠4.6V
1.48~1.52ms
t
d
V
2V
CC
Output
Undefined
Samsung Electronics