ISO7421

V

CC1

V

CC2

ISO7420E, ISO7420FE, ISO7421E, ISO7421FE

www.ti.com

SLLSE45F – DECEMBER 2010 – REVISED JULY 2015

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

ISO742x utilize single-ended TTL-logic switching technology. Its supply voltage range is from 3 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 (i.e.

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

standard.

9.2 Typical Application

ISO7421 can be used with Texas Instruments' mixed signal micro-controller, digital-to-analog converter,

transformer driver, and voltage regulator to create an isolated 4-20 mA current loop.

Figure 23. Isolated 4-20 mA Current Loop

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Product Folder Links: ISO7420E ISO7420FE ISO7421E ISO7421FE