hip6015cb Intersil Corporation, hip6015cb Datasheet - Page 6

• Manufacturer Part Number: hip6015cb
• Description: Buck Pulse-width Modulator Pwm Controller And Output Voltage Monitor
• Manufacturer: Intersil Corporation

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 200 A 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
NOTE: 0 = connected to GND or V
DS(ON)
IN
VID4
. When the voltage across the upper MOSFET (also
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
15A
10A
4V
2V
0V
5A
0A
to monitor the current. This method enhances the
FIGURE 4. OVER-CURRENT OPERATION
VID3
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
IN
PIN NAME
) exceeds the voltage across R
VID2
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
SS
TIME (20ms/DIV.)
VID1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
with a 10 A current sink and
6
SS
OCSET
, 1 = connected to V
VID0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
that is referenced to
NOMINAL OUTPUT
VOLTAGE DACOUT
TABLE 1. OUTPUT VOLTAGE PROGRAM
OCSET
OCSET
DD
1.80
1.85
1.90
1.95
2.00
2.05
0
0
0
0
0
0
0
0
0
0
, the
through pull-up resistors.
)
HIP6015
VID4
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
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
in the normal operating load range, find the R
from the equation above with:
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.
I
1. The maximum r
2. The minimum I
3. Determine I
PEAK
PEAK)
SS
OCSET
where I is the output inductor ripple current.
, and PWM operation resumes with the error amplifier
VID3
=
OCSET
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
determined by:
to smooth the voltage across R
I
-------------------------------------------------- -
OCSET
PIN NAME
DS(ON)
SS
r
VID2
DS ON
is the internal OCSET current source (200 A
, the soft start function inhibits PWM operation
PEAK
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
R
OCSET
DS(ON)
OCSET
variations. To avoid over-current tripping
SS
for
VID1
to 4V to complete its cycle. Figure 4
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
at the highest junction temperature.
I
from the specification table.
PEAK
VID0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
I
OUT MAX
OCSET
NOMINAL OUTPUT
VOLTAGE DACOUT
OCSET
+
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3.0
3.1
3.2
3.3
3.4
3.5
in the
0
I
SS
2
resistor
,