ISO7221

V

CC1

V

CC2

ISO7220A, ISO7220B, ISO7220C, ISO7220M

ISO7221A, ISO7221B, ISO7221C, ISO7221M

www.ti.com

SLLS755N – JULY 2006 – REVISED SEPTEMBER 2015

9 Application 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 ISO7220x and ISO7221x devices use single-ended TTL or CMOS-logic switching technology. The supply

digital isolators, because of 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

The ISO7221x device 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 19. Isolated 4 to 20 mA Current Loop

9.2.1 Design Requirements

Unlike optocouplers, which require external components to improve performance, provide bias (or limit current),

the ISO7220x and ISO7221x devices require only two external bypass capacitors to operate.

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Product Folder Links: ISO7220A ISO7220B ISO7220C ISO7220M ISO7221A ISO7221B ISO7221C ISO7221M