ISO7820F

UCC27423

PWM

MOSFET A

MOSFET B

21

ISO7820, ISO7820F

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SLLSEP0A – JULY 2015 – REVISED MARCH 2016

Product Folder Links: ISO7820 ISO7820F

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9 Applications and Implementation

NOTE

Information in the following applications sections is not part of the TI component

specification, and TI does not warrant its accuracy or completeness. TI’s customers are

responsible for determining suitability of components for their purposes. Customers should

validate and test their design implementation to confirm system functionality.

9.1 Application Information

The ISO7820 is a high-performance, dual-channel digital isolator with 5.7 kVRMS isolation voltage per UL 1577. It

utilizes single-ended CMOS-logic switching technology. Its supply voltage range is from 2.25 V to 5.5 V for both

supplies, VCC1 and VCC2. When designing with digital isolators, it is important to keep in mind that due to the

single-ended design structure, digital isolators do not conform to any specific interface standard and are only

intended for isolating single-ended CMOS or TTL digital signal lines. The isolator is typically placed between the

data controller (that is,

μC or UART), and a data converter or a line transceiver, regardless of the interface type

or standard.

9.2 Typical Application

ISO7820F can be used to isolate power MOSFETs from sensitive logic circuitry in Switch Mode Power Supplies

(SMPS) as shown below.

Figure 16. Isolated Switch Mode Power Supply

9.2.1 Design Requirements

For the ISO7820, use the parameters shown in Table 7.

Table 7. Design Parameters

PARAMETER

VALUE

Supply voltage

2.25 V to 5.5 V

Decoupling capacitor between VCC1 and GND1

0.1 µF

Decoupling capacitor from VCC2 and GND2

0.1 µF