hip6019cb Intersil Corporation, hip6019cb Datasheet - Page 14

• Manufacturer Part Number: hip6019cb
• Description: Advanced Dual Pwm And Dual Linear Power Control
• Manufacturer: Intersil Corporation

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.
P
LINEAR
SCH
=
I
------------------------------------------------------------ -
=
O
I
O
V
f
V
V
IN
V
IN
IN
–
–
V
V
OUT
OUT
2-265
f
).
HIP6019