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Publication Order Number:
AND8083/D
Semiconductor Components Industries, LLC, 2002
March, 2002 – Rev. 0
1
AND8083/D
Efficiency Improvements
Using 10 Volt
Schottky Diodes
Prepared by: Jim Spangler, Larry Hayes, Ron Perina
ON Semiconductor
ABSTRACT
This application note describes the advantages realized by
using 10 volt Schottky diodes in a variety of applications.
The major advantage of using a lower voltage Schottky is the
reduced forward voltage drop. This lower drop results in a
significant increase in efficiency. In addition, one can affect
a substantial cost advantage of using a single Schottky diode
as opposed to the use of a power FET as a synchronous
rectifier.
Lower Forward Voltage Drop
Figure 1 shows the relative improvement in forward
voltage drop, V
f
, which is made possible by the new 10 volt
Schottky technology. The comparison is made to industry
typical Schottky diodes using traditional low voltage
processes.
It is clear that such a significant improvement can have
major impact on the efficiency of many circuit applications.
The typical forward voltage drop of various low voltage
Schottky diodes is shown in Table 1. The data is taken from
the data sheet of each device [1, 2, 3, 4, 5, 6, 7] at 25°C. A
comparison can be made between a 10 volt device and a 20
or 30 volt device. Three surface mount packages are shown,
POWERMITE, SMA, and SMC. The forward voltage
drop is presented at five test currents in order to make
comparisons.
1. Notice the lower forward voltage drop of a 10 volt
device compared to a 20 or 30 volt device.
2. Also notice that in order to obtain a smaller
forward voltage drop, a higher current device can
be chosen. For example, the 4 Amp device,
MBRS410LT3 has a smaller forward voltage drop
than the 1 Amp or 2 Amp devices.
All Schottky diodes have a negative temperature
coefficient of approximately 1 mV/°C. The forward voltage
drop can be as much as 0.100 volts lower at 125°C when
compared to the voltage drop at 25°C.
Figure 1. V
F
Comparison
Industry
Typical
ON Semiconductor
V
F
Improvement
APPLICATION NOTE
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