Samsung SF-335T, Repair Manual

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CIRCUIT DESCRIPTION
<2> SERIAL INTERFACE
PIN NAME DESCRIPTION DIRECTION / TYPE
preg Pre-regulator control analog/output
Vin DC motor driver and 5V regulator input supply voltage power/input
DCMA DC motor drive half bridge A power/bidirectional
DCMB DC motor drive half bridge B power/bidirectional
DCPWM PWM input signal CMOS/input
nPA Paper motor phase A drive power/open drain
nPnA Paper motor phase nA drive power/open-drain
nPB Paper motor phase B drive power/open drain
nPnB Paper motor phase nB drive power/open drain
+12V +12V EEPROM programming voltage output
nSA Service station motor phase A drive power/open drain
nSnA Service station motor phase nA drive power/open drain
nSB Service station motor phase B drive power/open drain
nSnB Service station motor phase nB drive power/open drain
DATA Serial Data Input (and ACK output) CMOS/input
SCLK Serial Clock Input CMOS/input
GATE1 V1 gate drive power/output
SOURCE1 V1 source voltage return analog/input
Vfb V1 return to close loop analog/input
COMP1 V1 compensation pin analog
SWITCH +5V switching output power/output
COMP5 +5V compensation pin analog
+5V +5V input for logic and to close loop analog/input
Vdd Input Voltage power/input
CP1 Bootstrap capacitor pin 1 analog
CP2 Bootstrap capacitor pin 2 analog
Ground Ground analog
nRESET Active low totem pole reset output CMOS/output
Enable Chip Enable CMOS/input
CT Reset timing delay capacitor analog
SPWMA Stepper motor pwm phase A/nA CMOS/input
SPWMB Stepper motor pwm phase B/nB CMOS/input
Vp Boost voltage output for high side FETs power/output
GND (11) Used both as ground and as heatsinking analog