ZXGD3103 Datasheet, PDF (1/2 Pages) Diodes Incorporated – New Synchronous Rectifier Controller further improves power supply efficiency

Issue Number | 002
July 2010
New Product
Announcement
ZXGD3103N8
New Synchronous Rectifier Controller
further improves power supply efficiency
With the drive to save power gaining
momentum, synchronous
rectification is being adopted into
more and more power supply
designs. Replacing the secondary
side rectifier diodes with low on-
resistance MOSFETs can cut the
rectifier losses by 60~70% giving an
overall efficiency saving of up to
3.5%.
The ZXGD3103N8 has been designed
to control and switch the MOSFET to
provide optimum performance,
thereby minimising the switching
and on state losses to improve the
overall power supply efficiency.
Proportional Gate drive is the main
differentiator when compared to
competing solutions. By backing off
the voltage applied to the MOSFET
Gate as the Drain current falls
ensures that the detector does not
turn off the MOSFET too early in the
cycle resulting in lost efficiency.
Competing solutions use direct drive
which means the MOSFET is kept
fully enhanced often resulting in the
detector threshold being reached
before the on cycle is complete.
The other advantage of the
Proportional Gate Drive is that at the
point when the MOSFET is required
to turn-off the current, there is less
Gate charge to overcome than if the
MOSFET was still fully enhanced
ensuring faster turn-off to minimize
shoot through and body diode
conduction.
For samples and quotations please
contact your nearest Diodes sales
office or representative.
N/C 1
REF 2
GATEL 3
GATEH 4
SO-8
8 DRAIN
7 BIAS
6 GND
5 VCC
The Diodes’ Advantage
Proportional Gate Drive
Prevents premature turn-off of the synchronous MOSFET giving optimum performance
Turn-off propagation delay and fall times of 15 and 21ns respectively
Prevents reverse conduction and minimises shoot through current ensuring high
efficiency operation
Turn-on propagation delay of 150ns
Reduces body diode conduction in the synchronous MOSFET, reducing losses.
Suitable for power supplies switching up to 300kHz
Operating voltage range 5 to 15V
Adaptable in various supply configuration
180V sensing input
Permits direct connection to the MOSFET Drain without the need for external
protection components
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