Samsung ML-2251N/XAA Service Manual page 30

Summary of Product
4.3 Main PBA(SPL Model)
The Engine Board and Controller Board have been integrated into a single PBA. This consists of the CPU and
printer control functions. The CPU functions as the bus controller, I/O handler, motor driver and PC interface. The
main board sends the Current Image Video data to the LSU and manages the Electrophotographic printing
process. Circuits on the PBA drive include the main motor (paper feed, cartridge, fuser), clutch driver, pre-transfer
lamp driver, heat-lamp driver and fan driver.
The signals from the paper feed jam sensor and paper empty sensor are inputted to the main board from the
power supply PBA..
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1
LOW DROP FIXED AND ADJUSTABLE POSITIVE VOLTAGE REGULATORS(LD1117DT) U1
2
LOW POWER DUAL BIPOLAR COMPARATORS(LM393D) U2
3
SPREAD SPECTRUM CLOCK GENERATOR(CY25811) U4
4 CPU X-TAL(12MHz) OSC1
5 SDRAM(K4S641632H) U6, U15
6 LOW VOLTAGE HEX INVERTER WITH 5V TOLERANT SCHMITT TRIGGER INPUTS(74LCX14) U7
7 MOTOR DRIVER(A3977SLP) U9
8 GRAPHIC PROCESSOR ASIC(SPGPM) U11
LOW VOLTAGE HEX INVERTER WITH 5V TOLERANT SCHMITT TRIGGER INPUTS(74LCX14) U24
9
PARALLEL PORT SINGLE TERMINATION NETWORK(ST1284) U23
10
LOW VOLTAGE IEEE 161284 TRANSLATING TRANSCEIVER(161284) U22
11
VIDEO X-TAL(19.6MHz) OSC3
12
USB 2.0(NET2270) U25
13
USB X-TAL(30MHz) OSC4
14
LOW VOLTAGE OCTAL D-TYPE FLIP-FLOP(74LVX273) U14, U19
15
LOW VOLTAGE BIDIRECTIONAL TRANSCEIVER(74LCX245) U10
16
FLASH MEMOTY(29LV160DB) U13
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