Xilinx ML310 manual 17ATX Power Distribution and Voltage Regulation

Board Hardware

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Note: An Antec, model SL250S, ATX Power Supply is delivered with your ML310. The Antec User’s Manual is provided in the Data sheets section on the ML310 CDROM. Prior to installation please read the Installation section of the Antec User’s Manual which describes the red voltage switch power setting on your Antec SL250S supply.

Check the red power supply voltage switch setting before installation. It should be the same as your local power voltage (115V for North America, Japan, etc. and 230V for Europe and many other countries). Change the voltage setting if necessary. Failure to take this precaution could result in damage to your equipment and could void your warranty.

The ML310 requires a variety of voltages as is required by the different logic devices used in the ML310 board design. The varieties of voltages are derived from the 5.0V supply and regulated on board as shown in Figure 2-17.

Figure 2-17shows the power distribution and regulation for the ATX-compatible power supply.

J18
					NOTE: Typical ATX power supplies may not
Pin 1	Pin 11		VCC5V		produce a well-regulated 3.3V supply unless
					there is a minimum load on the 5V output.
3.3-A	3.3-C		VCC12V_N		Therefore 3.3V is regulated separately for
3.3-B	-12V				on-board use.
COM-A	COM-D		VCC12V_P
5V-A	PS-ON		VCC3V3_ATX
COM-B	COM-E				VCC3V3
5V-B	COM-F
					NOTE: These resistors (R185-188) allow the 3.3v regulator
COM-C	COM-G
					to be nostuffed and 3.3v power taken directly from the ATX
PW-OK	-5V
					supply in the case where it is well-behaved given the load
5VSB	5V-C				on the other outputs.	U3
12V	5V-D		R185-188		VCC12V_P		AC_AVDD
			Nostuff				(5.0V @ 500mA)
						LT1763CS8
VCC5V	U9				VCC3V3	U40
		USB_AVC					MGT_AVCC
		(5V @ 500 mA)					(2.5V @ 3A)
				U14

MIC2076-2

U41

VCC3_PCI (3.0V @ 500mA)

LT1763CS8

U8

VCC1V5 (1.5V @ 10A)

SC10A-DAC

	VCC3V3	LT1764AEQ
	(3.3V @ 10A)		U34
				MGT_VTT
SC10A-DAC				(1.8V @ 500 mA)
	U10
	VCC2V5		LT1763CS8
	(2.5V @ 10A)		U25
				DDR_VTT
SC10A-DAC				(1.25 V @ 3A)
				VREF_DDR
			ML655460

Figure 2-17:ATX Power Distribution and Voltage Regulation

Several voltage monitors, MC34161D, monitor all regulated power on the ML310 board. Each of the voltage monitors is connected to power indicator LEDs as shown in

Figure 2-18. The indicator LEDs will illuminate RED if a regulated supply voltage is out of spec and will illuminate Green if the regulated supply voltage is nominal. Each regulated supply voltage has a corresponding test point located near its indicator LED. Please review the ML310 schematics and the MC34161D data sheet for more detailed information.

ML310 User Guide	www.xilinx.com	59
UG068 (v1.01) August 25, 2004	1-800-255-7778