iru3004 International Rectifier Corp., iru3004 Datasheet - Page 8

• Manufacturer Part Number: iru3004
• Description: 5-bit Programmable Synchronous Buck Controller Ic With Dual Ldo Controller
• Manufacturer: International Rectifier Corp.

IRU3004
TYPICAL APPLICATION
Pentium with AGP
8
VID4
VID3
VID2
VID1
VID0
3.3V
C1
Figure 4 - Typical application of IRU3004 in a Pentium with AGP where the power dissipation of the 3.3V
linear regulator is equally distributed between Q3 and Q4 pass transistors. This equal distribution is
possible by accurately regulating the first regulator using the IRU3004 linear controller and its internal
1% reference voltage while the second controller regulates the output of the first regulator from 4.17V to
3.3V, thereby distributing the power dissipation equally.
12V
5V
C13
C2
R18
L1
C3
C4
Ct
SS
V12
D4
C5
V5
D3
C6
CS+
D2
R1
R2
HDrv
IRU3004
Q1
D1
CS-
D0
R3
www.irf.com
LDrv
V
FB2
PGd
Gnd
C8
Q2
R5
3.3V
V
R4
Lin2
FB3
V
Lin1
C7
FB1
Power Good
C9
R16
L2
R9
R12
R 1 1
R17
C16
R13
Q3
Q4
C15
C14
C10
V
R14
R15
R8
R7
OUT
3
C 1 1
C12
07/16/02
Rev. 1.7
3.3V