Ampro Corporation Littleboard 550 manual Power Interface J10, Power Monitor, CPU Fan, Tag

Chapter 3 Hardware

Power Interface (J10)

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).

Table 3-27. Power Interface Pin/Signal Descriptions (J10)

Pin #	Signal	Description
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 Monitor

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.

CPU Fan

Table 3-28. CPU Fan (J2)

Pin #	Signal	Description
1	GND	Ground
2	+5	+5.0 volts DC +/- 5%
3	TAG	Fan Speed Tachometer

Note: The shaded area denotes power or ground.

LittleBoard 550 Reference Manual 61