Ampro Corporation Littleboard 550 Manuel D’Utilisation

LittleBoard 550

Reference Manual

61

The LittleBoard 550 uses five separate voltages on the board, but only one of the voltages is provided
externally (+5 volts) through the external connector, which uses a 7-pin vertical header with 0.156”
(3.96mm) spacing.  Holes for a right angle mounting header are also available at J10.  All the onboard
voltages are derived from the externally supplied +5 volts DC +/- 5%.  The onboard voltages provide the
CPU core voltages as well as other voltages used on the board.

Table 3-27 gives the pin outs and signals for Power supply connector (J10).

1

+5V

+5.0 volts DC +/- 5%

2

GND

Ground

3

GND

Ground

4

+12V

This +12V is are for BUS power only (optional)

5

+3.3V

This +3.3V is for BUS power only (optional)

6

GND

Ground

7

+5V

+5.0 volts DC +/- 5%

Notes: The shaded area denotes power or ground.  The +12Vand +3.3V on the Power Interface
connector (J10) are used for the PCI and ISA bus power and must be supplied externally.  The -5V
and –12V are supplied from an external power supply through the Utility 1 connector (J16).

Power supply monitoring is performed by the precision triple supply monitor, LTC 1326.  This chip
monitors the system voltages and provides an auto-reset or external push button reset capability.  The
LTC 1326 monitors three separate voltages Vcore, +5V, and +3.3V.  If any of these voltages drop below
–10% of the nominal voltage, the POWER GOOD output is driven low causing a system reset.

1

GND

Ground

2

+5

+5.0 volts DC +/- 5%

3

TAG

Fan Speed Tachometer

Note: The shaded area denotes power or ground.