7

Figure 6 shows the critical power components of the

converter. To minimize the voltage overshoot the

interconnecting wires indicated by heavy lines should be

part of ground or power plane in a printed circuit board. The

components shown in Figure 6 should be located as close

Locate the HIP6008 within 3 inches of the MOSFET, Q1.

The circuit traces for the MOSFET’s gate and source

connections from the HIP6008 must be sized to handle up to

1A peak current.

Figure 7 shows the circuit traces that require additional

layout consideration. Use single point and ground plane

construction for the circuits shown. Minimize any leakage

close to the SS pin because the internal current source is

only 10

to the BOOT and PHASE pins.

Feedback Compensation

+

-

BAND GAP

REFERENCE

1.26V

VID0

VID1

VID2

VID3

FB

COMP

DACOUT

ERROR

AMPLIFIER

21.5k

Ω

1.7k

Ω

10.7k

Ω

5.4k

Ω

2.7k

Ω

2.9k

Ω

DAC

+

-

FIGURE 5. DAC FUNCTION SCHEMATIC

CO

UGATE

PHASE

Q1

D2

RETURN

HIP6008

FIGURE 6. PRINTED CIRCUIT BOARD POWER AND

GROUND PLANES OR ISLANDS

+12V

HIP6008

SS

GND

BOOT

D1

CO

Q1

D2

PHASE

FIGURE 7. PRINTED CIRCUIT BOARD SMALL SIGNAL

LAYOUT GUIDELINES

OSC

REFERENCE

LO

CO

ESR

ERROR

AMP

PWM

DRIVER

(PARASITIC)

+

-

DACOUT

R1

R3

R2

C3

C2

C1

COMP

FB

HIP6008

COMPARATOR

DETAILED COMPENSATION COMPONENTS

PHASE

+

-

+

-

FIGURE 8. VOLTAGE - MODE BUCK CONVERTER COMPEN-

SATION DESIGN

HIP6008