9

The OC trip point varies with MOSFET’s temperature. To avoid

over-current tripping in the normal operating load range,

where

ΔI is the output inductor ripple current.

For an equation for the output inductor ripple current see the

section under component guidelines titled ‘Output Inductor

Selection’.

OUT1 Voltage Program

The output voltage of the PWM converter is programmed to

designed to supply the microprocessor core voltage. The

voltage identification (VID) pins program an internal voltage

reference (DACOUT) through a TTL-compatible 5-bit

digital-to-analog converter. The level of DACOUT also sets

the PGOOD and OVP thresholds. Table 1 specifies the

DACOUT voltage for the different combinations of

connections on the VID pins. The VID pins can be left open

for a logic 1 input, because they are internally pulled up to

+5V by a 10

μA (typically) current source. Changing the VID

inputs during operation is not recommended. The sudden

change in the resulting reference voltage could toggle the

PGOOD signal and exercise the over-voltage protection.

The ‘11111’ VID pin combination resulting in an INHIBIT

disables the IC and the open-collector at the PGOOD pin.

UGATE

OCSET

PHASE

OVER-

CURRENT1

+

-

GATE

CONTROL

VCC

OC1

200

μA

+

+

FIGURE 9. OVER-CURRENT DETECTION

PWM

DRIVE

HIP6018B

VCC

LGATE

PGND

PIN NAME

NOMINAL

OUT1

VOLTAGE

DACOUT

VID4

VID3

VID2

VID1

VID0

01

11

1

1.30

01

11

0

1.35

01

10

1

1.40

01

10

0

1.45

01

01

1

1.50

01

01

0

1.55

01

00

1

1.60

01

00

0

1.65

00

11

1

1.70

00

11

0

1.75

00

10

1

1.80

00

10

0

1.85

00

01

1

1.90

00

01

0

1.95

00

00

1

2.00

00

00

0

2.05

11

11

1

INHIBIT

11

11

0

2.1

11

10

1

2.2

11

10

0

2.3

11

01

1

2.4

11

01

0

2.5

11

00

1

2.6

11

00

0

2.7

10

11

1

2.8

10

11

0

2.9

10

10

1

3.0

10

10

0

3.1

10

01

1

3.2

10

01

0

3.3

10

00

1

3.4

10

00

0

3.5

through pull-up resistors.

HIP6018B