2-68

For an equation for the ripple current see the section under component guidelines titled ‘Output Inductor Selection’

.

A small ceramic capacitor should be placed in parallel with

presence of switching noise on the input voltage.

Output Voltage Program

The output voltage of a HIP6004A converter is

internal voltage reference (DACOUT) with a TTL-

compatible 5-bit digital-to-analog converter (DAC). The

level of DACOUT also sets the PGOOD and OVP

thresholds. Table 1 specifies the DACOUT voltage for the

32 different combinations of connections on the VID pins.

The output voltage should not be adjusted while the

converter is delivering power. Remove input power before

changing the output voltage. Adjusting the output voltage

during operation could toggle the PGOOD signal and

exercise the overvoltage protection.

All VID pin combinations resulting in a 0V output setting

activate the Power-On Reset function, disable the gate drive

circuitry and output a 0 logic at PGOOD pin.

Application Guidelines

Layout Considerations

As in any high frequency switching converter, layout is very

important. Switching current from one power device to

another can generate voltage transients across the

impedances of the interconnecting bond wires and circuit

traces. These interconnecting impedances should be

minimized by using wide, short printed circuit traces. The

critical components should be located as close together as

possible, using ground plane construction or single point

grounding.

Figure 5 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 5 should be located as close

TABLE 1. OUTPUT VOLTAGE PROGRAM

PIN NAME

NOMINAL OUTPUT

VOLTAGE DACOUT

PIN NAME

NOMINAL OUTPUT

VOLTAGE DACOUT

VID4

VID3

VID2

VID1

VID0

VID4

VID3

VID2

VID1

VID0

01111

0

11111

0

01110

0

11110

2.1

01101

0

11101

2.2

01100

0

11100

2.3

01011

0

11011

2.4

01010

0

11010

2.5

01001

0

11001

2.6

01000

0

11000

2.7

00111

0

10111

2.8

00110

0

10110

2.9

0

0

1

0

1

1.80

1

0

1

0

1

3.0

0

0

1

0

0

1.85

1

0

1

0

0

3.1

0

0

0

1

1

1.90

1

0

0

1

1

3.2

0

0

0

1

0

1.95

1

0

0

1

0

3.3

0

0

0

0

1

2.00

1

0

0

0

1

3.4

0

0

0

0

0

2.05

1

0

0

0

0

3.5

PGND

LGATE

UGATE

PHASE

RETURN

HIP6004A

FIGURE 5. PRINTED CIRCUIT BOARD POWER AND

GROUND PLANES OR ISLANDS

HIP6004A