HIP6002CB datasheet(6/12 Pages) INTERSIL

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inhibits PWM operation. The soft-start function recharges

CSS, and PWM operation resumes with the error amplifier

clamped to the SS voltage. Should an overload occur while

recharging CSS, the soft start function inhibits PWM operation

while fully charging CSS to 4V to complete its cycle. Figure 4

shows this operation with an overload condition. Note that the

inductor current increases to over 15A during the CSS

charging interval and causes an over-current trip. The

converter dissipates very little power with this method. The

measured input power for the conditions of Figure 4 is 2.5W.

The over-current function will trip at a peak inductor current

(IPEAK) determined by:

where IOCSET is the internal OCSET current source (200µA -

typical). The OC trip point varies mainly due to the MOSFET’s

rDS(ON) variations. To avoid over-current tripping in the normal

operating load range, find the ROCSET resistor from the

equation above with:

1. The maximum rDS(ON) at the highest junction

temperature.

2. The minimum IOCSET from the Specification Table.

3. Determine IPEAK for IPEAK >IOUT(MAX) +(∆I)/2, where ∆I

is the output inductor ripple current.

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

ROCSET to smooth the voltage across ROCSET in the

presence of switching noise on the input voltage.

Output Voltage Program

The output voltage of a HIP6002 converter is digitally

programmed to levels between 2VDC and 3.5VDC. The

voltage identiﬁcation (VID) pins program an internal voltage

reference (DACOUT) with a 4-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 16 combinations of open or short connections on the VID

pins. The output voltage should not be adjusted while the

converter is delivering power. Remove input power or inhibit the

converter (EN pin to GND) before changing the output voltage.

Adjusting the output voltage during operation could toggle the

PGOOD signal and exercise the overvoltage protection.

The DAC function is a precision non-inverting summation

ampliﬁer shown in Figure 5. The resistor values shown are

only approximations of the actual precision values used.

Grounding any combination of the VID pins increases the

DACOUT voltage. The ‘open’ circuit voltage on the VID pins

is the band gap reference voltage, 1.26V.

TIME (20ms/DIV)

10A

15A

FIGURE 4. OVER-CURRENT OPERATION

PEAK

OCSET

•

DS(ON)

---------------------------------------------------

TABLE 1. OUTPUT VOLTAGE PROGRAM

PIN NAME

NOMINAL

DACOUT

VOLTAGE

VID3

VID2

VID1

VID0

1111

2.0

1110

2.1

1101

2.2

1100

2.3

1011

2.4

1010

2.5

1001

2.6

1000

2.7

0111

2.8

0110

2.9

0101

3.0

0100

3.1

0011

3.2

0010

3.3

0001

3.4

0000

3.5

NOTE: 0 = connected to GND or VSS, 1 = OPEN.

HIP6002

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