HIP6004DCB Intersil, HIP6004DCB Datasheet - Page 7

• Manufacturer Part Number: HIP6004DCB
• Description: IC CTRLR PWM VOLTAGE MON 20-SOIC
• Manufacturer: Intersil

Specifications of HIP6004DCB

• Pwm Type: Voltage Mode
• Number Of Outputs: 1
• Frequency - Max: 1MHz
• Duty Cycle: 100%
• Voltage - Supply: 5 V ~ 12 V
• Buck: Yes
• Boost: No
• Flyback: No
• Inverting: No
• Doubler: No
• Divider: No
• Cuk: No
• Isolated: No
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 20-SOIC (7.5mm Width)
• Frequency-max: 1MHz
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Over-Current Protection
The over-current function protects the converter from a
shorted output by using the upper MOSFET’s on-resistance,
r
converter’s efficiency and reduces cost by eliminating a
current sensing resistor.
The over-current function cycles the soft-start function in a
hiccup mode to provide fault protection. A resistor (R
programs the over-current trip level. An internal 200μA current
sink develops a voltage across R
V
referenced to V
over-current function initiates a soft-start sequence. The soft-
start function discharges C
inhibits PWM operation. The soft-start function recharges
C
clamped to the SS voltage. Should an overload occur while
recharging C
while fully charging C
shows this operation with an overload condition. Note that the
inductor current increases to over 15A during the C
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
(I
where I
typical). The OC trip point varies mainly due to the
MOSFET’s r
tripping in the normal operating load range, find the R
resistor from the equation above with:
I
DS(ON)
PEAK
1. The maximum r
IN
PEAK)
SS
15A
10A
. When the voltage across the upper MOSFET (also
temperature.
, and PWM operation resumes with the error amplifier
5A
0A
4V
2V
0V
=
OCSET
determined by:
to monitor the current. This method enhances the
I
---------------------------------------------------- -
OCSET
FIGURE 4. OVER-CURRENT OPERATION
DS(ON)
SS
r
DS ON
is the internal OCSET current source (200μA
IN
, the soft start function inhibits PWM operation
) exceeds the voltage across R
x R
(
DS(ON)
OCSET
variations. To avoid over-current
SS
)
to 4V to complete its cycle. Figure 4
TIME (20ms/DIV)
SS
at the highest junction
with a 10μA current sink and
7
OCSET
that is referenced to
OCSET
SS
OCSET
OCSET
, the
HIP6004D
)
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
R
presence of switching noise on the input voltage.
Output Voltage Program
The output voltage of a HIP6004D converter is programmed
to discrete levels between 1.100V
voltage identification (VID) pins program an 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.
‘11111’ VID pin combination resulting in a 0V output setting
activates the Power-On Reset function and disables the gate
drives circuitry. For this specific VID combination, though,
PGOOD asserts a high level. This unusual behavior has been
implemented in order to allow for operation in dual-
microprocessor systems where AND-ing of the PGOOD signals
from two individual power converters is implemented.
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.
2. The minimum I
3. Determine I
OCSET
where ΔI is the output inductor ripple current.
to smooth the voltage across R
PEAK
OCSET
for
I
PEAK
from the specification table.
>
I
DC
OUT MAX
and 1.850V
(
OCSET
)
+
(
ΔI
DC
) 2 ⁄
in the
. The
July 13, 2005
,
FN4855.3