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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.

New Product

Announcement

New Synchronous Rectifier Controller

further improves power supply efficiency

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

The Diodes’ Advantage

ZXGD3103N8

Issue Number | 00

2

July 2010

GATEL 3

GATEH 4

REF 2

N/C 1

8 DRAIN

7 BIAS

6 GND

SO-8