3. Applications

The following examples illustrate typical circuit configurations using the Si8751/52.

3.1 DC SSR Example

The Si875x device can be used to control a dc load as shown in the following figure:

MCAP1

GATE

SOURCE

IN

MCAP2

VDD

TT

GND

VDC

DC Load

Figure 3.1. Driving an FET for DC Load Including Miller Clamp Capacitor

In this configuration, the Si8751 charges the gate of the external FET; turning it on. This switches on power, supplied by VDC, to the

load. The output side circuitry is identical if using the Si8752.

3.2 AC SSR Example

The Si875x can be used to control power to an ac load using the following circuit:

AC Load

AC

Supply

MCAP1

GATE

SOURCE

IN

VDD

TT

GND

MCAP2

Figure 3.2. Driving FETs for AC Load Switching

In this configuration, both FET’s are turned on by the charge delivered by the Si8751. This allows ac current to flow to the load. When

the Si875x is turned off, charge is drained form the gates of both FET’s and the ac current is turned off. The output side circuitry is

identical if using the Si8752.

Si8751/52 Data Sheet • Applications

Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • sales@skyworksinc.com • www.skyworksinc.com

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206331A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice • July 27, 2022

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