SPC8104 S-MOS Systems, SPC8104 Datasheet - Page 264

• Manufacturer Part Number: SPC8104
• Description: VGA LCD CONTROLLER
• Manufacturer: S-MOS Systems

SDU8104B
Rev 1.0 ISA Bus Evaluation Board
SPC8104
0B
Adjustable Core Logic Power Supply
An independent power supply for the core section (VDD CORE) is provided. This power supply
(PCBVDD1) can be adjustable between 1.8 V and 3.9 V @ 1 A. Adjust R13 appropriately.
Adjustable I/O Logic Power Supply
Another independent power supply (PCBVDD2) is required to supply the 3.3 V I/O VDD pins on
the SPC8104F0A. All of the I/O pins are connected to the one power rail. This power supply
(PCBVDD2) can be adjustable between 1.8 V and 3.9 V @ 1 A. Adjust R19 appropriately.
3.3V Power Supply
There is a third on-board power supply which is used to provide 3.3v to devices that should not be
adjusted when testing the 8104 under variable voltage conditions. Refer to the schematics for
details.
Voltage Translation Circuitry
Voltage translation circuitry is required on all ISA-Bus interface signals to prevent the forward
biasing of the input protection diodes of the SPC8104F0A Bi-directional control of the data bus is
controlled by the output signal RDACK#. The LCD interface also has translation circuits as most
panels require a 5.0v interface.
Power Measurement Capabilities
All associated 8104 power pins (VDD CORE and VDD IO) will have a 1 ohm 1% resistor in series
with it for calculation of power consumption of the individual logic sections.
EV1-12
412-1.0
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