EV7718A_S0_R0 Parameters Subject to ChangeParameters Subject to ChangeParameters Subject to ChangeParameters Subject to Change Without NoticeWithout NoticeWithout NoticeWithout Notice

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FEATURES

� Supports DCM, Quasi-Resonant, CrCM and

CCM operation

� Support the Flyback topology

� Supports High-side and Low-side

Rectification

� Output voltage directly supply VCC

� Low quiescent current

� Under-voltage protection

� Fast driver capability for CCM operation

� SOP-8 package

APPLICATIONS

�� Flyback Converter

DESCRIPTION

JW®7718A is a synchronous rectifier, used for the

secondary side rectification of Flyback. By

drivingan internal MOSFET, JW7718A is able to

significantly improve the efficiency comparing

with the conventional Diode rectifier.

When JW7718A senses VDS of

internalMOSFETless than -300mV, it turns on the

internal MOSFET. Once the VSW is greater than

-10mV, JW7718A turns off the internal MOSFET.

JW7718A supports multiple operation modes,

such as DCM, CrCM, CCM and Quasi-Resonant.

By implementing the Joulwattproprietary

technology, JW7718A is able to handle CCM

operation.

JW7718A is available in SOP-8 package.

EVALUATION BOARD

4400VV SSRR

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SCHEMATIC

Figure-1 100V SR

BILL OF MATERIALS for 100V SR

Quantity Designator Comment Description Footprint Manufacturer Manufacturer P/N

1 C1 2.2uF/16V/10% Capacitor 0603 SAMSUNG CL10B225K08NNN0

1 C2 1nF/100V/10% Capacitor 0805 SAMSUNG

1 R1 20R/5% Resistor 0805 UNIOHM

1 U1 JW7718A IC SOT23-6 Joulwatt JW7718A

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PRINTED CIRCUIT BOARD LAYEROUT

Figure-2Top Silk Layer

Figure-3Top Layer

Figure-4Bottom Silk Layer

Figure-5Bottom Layer

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QUICK START

1. The GND pin is connectedwith the output power ground. And the SW pin is connected with the

second winding (“B”).

2. The Vo pin isconnected with the output “Vo+”.

3. To get more information, please refer to the datasheet of JW7718A.

4. Figure-6shows the connection of 100V SR demo.

Figure-6 Typical connection for SR demo

EV7718_S0_R0

JW7718A_S0_R0 Rev.0.1 JoulWatt

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TYPICAL PERFORMANCE

JW7718A typical operation waveforms

1.1 Steady State-- No load (Burst mode)

1.2 Steady State-- Half load& full load

1.3 Steady State–No load (Burst mode)

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TYPICAL PERFORMANCE CHARACTERISTICS

waveforms with a5V/2.4A flybackadapter.

(Burst mode)

full load

(Burst mode)

JoulWatt

5

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1.4 Steady State-- Half load& Full Load

2.1 Startup--Full Load

2.2 Startup-- Full Load

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Full Load

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3.1 Startup–Load short-circuit

4.1 Load short-circuit–Full Load

5. Power off–Full Load

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JoulWatt

7

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IMPORTANT NOTICE

� Joulwatt Technology Inc. reserves the right to make modifications, enhancements, improvements,

corrections or other changes without further notice to this document and any product described herein. � Any unauthorized redistribution or copy of this document for any purpose is strictly forbidden.

� Joulwatt Technology Inc. does not warrant or accept any liability whatsoever in respect of any products

purchased through unauthorized sales channel.

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