Voltage Regulator Circuit Descriptions; Lt1764A Voltage Regulators - Xilinx Virtex-4 ML455 User Manual

Voltage Regulators
Table 3-9: Power Supplies
Designation
None
None
U3
U2
U7
U4
VR1
Notes:
1. On-board voltage regulators are shown in the schematics provided on the kit CD, on schematic sheet 17.

Voltage Regulator Circuit Descriptions

This section describes the voltage regulators on the ML455 board.

LT1764A Voltage Regulators

Figure 3-5
which have the same basic topology. The output adjust resistor is calculated from the
formula given in the Linear Technology data sheet (part number LT1764AF) at
www.linear-tech.com):
www.BDTIC.com/XILINX
Virtex-4 ML455 PCI/PCI-X Board
UG084 (v1.0) May 17, 2005
Input Output I
Max
5V N/A PCI
3.3V N/A PCI
5V 3.0V 3A
3.3V 2.5V 3A
3.3V 1.8V 0.5A
3.3V 1.2V 3A
5V 1.25V 6A
shows the LT1764A 5-pin linear 3A capable voltage regulators (U2, U3, and U4),
www.xilinx.com
Device Type
Edge Connector Voltage Regulator Input U3
A5, A8, A61, A62, B5,
PCI 64-bit Socket J1
B6, B61, B62
LED Power D5, D6
VR1 1.25V V
Edge Connector Voltage Regulator Input for
U2, U4, and U7.
A10, A16, A21, A27,
A33, A39, A45, A53,
LED Power D1, D2, D3, D4
A59, A66, A75, AB4,
Y3 Osc V
B19, B25, B31, B36,
B91, B93, B54, B59,
PCI 64-bit Socket J1
B70, B79, B88
LT1764A (adj.) U10 LX25 Banks 3, 6, 10
V
U8 Clk Buf V
LT1764A (adj.) U10 LX25 Banks 1, 2, 4, 7, 8
V
J4 SODIMM Socket
U5 MAX3316 V
U1 XC32FP V
Y1,Y2 Oscillator V
P9 PC IV Cable Connector
LT1763CS8 U6 XC (CPLD) V
U1 XC32FP V
LT1764A (adj.) U10 LX25 V
PTH0505Y-AH J4 SODIMM Socket V
Memory Term. R Pullup V
Primary Use
Regulator
TT
CC
CCO
CC
and V
CCO CCAUX
CC
CCO
CC
CC
, V
CCINT CCJ
CCINT
REF
21
R