11

FN9030.7

March 4, 2005

ISL6522 DC-DC Converter Application

Circuit

Figure 11 shows a DC-DC converter circuit for a

microprocessor application, originally designed to employ

the HIP6006 controller. Given the similarities between the

HIP6006 and ISL6522 controllers, the circuit can be

implemented using the ISL6522 controller without any

modifications. Detailed information on the circuit, including a

complete bill of materials and circuit board description, can

be found in Application Note AN9722. See Intersil’s home

page on the web: http://www.intersil.com.

ISL6522

RT

FB

COMP

SS

REF

-

+

GND

+

-

OSC

VCC

C1-3

L1

C6-9

0.1

µF

2x 1

µF

0.1

µF

1

µF

15K

3x 680

µF

4x 1000

µF

UGATE

OCSET

PHASE

BOOT

SPARE

CR1

Q1

3.01K

1000pF

CR2

C13

R1

R4

C15

R5

C14

C12

C17-18

C19

R6

C20

4148

U1

RTN

14

2

10

9

8

7

4

5

1

3

SPARE

PGND

LGATE

12

11

PVCC

13

JP1

Q2

1206

1206

MBR

340

RTN

ENABLE

R2

1K

COMP

TP1

PHASE

TP2

6

R7

10K

MONITOR AND

PROTECTION

+

-

+

-

C16

0.01

µF

33pF

SPARE

Component Selection Notes:

C1-C3 - Three each 680

µF 25W VDC, Sanyo MV-GX or equivalent.

C6-C9 - Four each 1000

µF 6.3W VDC, Sanyo MV-GX or equivalent.

L1 - Core: micrometals T50-52B; winding: ten turns of 17AWG.

CR1 - 1N4148 or equivalent.

CR2 - 3A, 40V Schottky, Motorola MBR340 or equivalent.

Q1, Q2 - Fairchild MOSFET; RFP25N05

FIGURE 11. DC-DC CONVERTER APPLICATION CIRCUIT

R3

1K

ISL6522