HIP6019B_05 INTERSIL [Intersil Corporation], HIP6019B_05 Datasheet - Page 14

• Manufacturer Part Number: HIP6019B_05
• Description: Advanced Dual PWM and Dual Linear Power Control
• Manufacturer: INTERSIL [Intersil Corporation]

diode must be a Schottky type to prevent the lossy parasitic
MOSFET body diode from conducting. It is acceptable to
omit the diode and let the body diode of the lower MOSFET
clamp the negative inductor swing, but efficiency might drop
one or two percent as a result. The diode's rated reverse
breakdown voltage must be greater than twice the maximum
input voltage.
PWM2 MOSFET and Schottky Selection
The power dissipation in PWM2 converter power devices is
similar to PWM1 except that the power losses of the lower
device are representative of a Schottky diode instead of a
MOSFET. The transistor power losses follow the PWM1
upper MOSFET equation, so the selection process should
be somewhat similar. The equation below describes the
conduction power losses incurred by the Schottky diode.
As it can be observed, conduction losses in the Schottky
diode are proportional with the forward voltage drop (V
Linear Controller MOSFET Selection
The main criteria for selection of MOSFET for the linear
regulator is package selection for efficient removal of heat.
The power dissipated in a linear regulator is:
P
Select a package and heatsink that maintains the junction
temperature below the maximum rating while operating at
the highest expected ambient temperature.
HIP6019B DC-DC Converter Application
Circuit
Figure 15 shows an application circuit of a power supply for
a microprocessor computer system. The power supply
provides the microprocessor core voltage (V
voltage (V
generator voltage (V
detailed information on the circuit, including a Bill-of-
Materials and circuit board description, see Application Note
AN9800. Also see Intersil’s web page
(http://www.intersil.com).
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without
notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and
reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result
from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries.
P
LINEAR
SCH
=
I
------------------------------------------------------------ -
O
=
OUT2
×
I
O
V
×
f
All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems.
×
), the GTL bus voltage (V
(
V
(
V
V
IN
IN
IN
Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality
–
OUT4
–
V
V
For information regarding Intersil Corporation and its products, see www.intersil.com
OUT
OUT
) from +5V
)
)
14
DC
and +12V
OUT3
OUT1
) and clock
), the I/O
DC
. For
f
).
HIP6019B
April 13, 2005
FN4587.1