1 Features

• Eight Configurable IEC 61131-2 Type 1, 2, 3

Isolated Digital Inputs

• Low Power and Heat Dissipation

– Selectable Input Current Limit

– Field Side LED Drivers Using Input Current

• Supports Sourcing and Sinking Type Inputs

• Wire-break Detection in Sink Mode

• Integrated Field Supply Voltage Monitor

• Programmable Glitch Filters

• Built in CRC check across Barrier

• Serial SPI and Parallel Output Options

– Supports SPI Daisy Chaining

– Supports SPI Burst Mode

• Integrated IEC ESD and Surge Protection

• High CMTI(Typ): 75 kV/μs

• VCC1 Logic Supply Voltage Range: 1.71 V to 5.5 V

• AVCC Field Supply Voltage Range (Sink mode):

8.5 V to 36 V

• AVCC Field Supply Voltage Range (Source mode):

13 V to 36 V

• Ambient Temperature Range: –40°C to 125°C

• Small Footprint 38-SSOP Package

• Safety-related certifications:

– 4242-VPK VIOTM and 637-VPK VIORM per DIN V

VDE V 0884-11

– 3000-VRMS Isolation for 1 Minute per UL 1577

– IEC 62368-1, IEC 61010-1 and GB

4943.1-2011Certifications

– All Certifications Planned

2 Applications

• Programmable Logic Controllers (PLC)

– Digital Input Modules

– Mixed Input Modules

• Motor Drive Digital Inputs

• Binary Input Modules

• CNC Control

• Industrial Transport Digital Inputs

3 Description

The ISO1228 is an eight-channel isolated 24-V digital

input receivers, configurable to IEC 61131-2 Type

1, 2, and 3 characteristics. The ISO1228 includes

resistor-programmable accurate current limit and

field side input-current-powered LED indication to

reduce system power dissipation and reduce board

temperatures. ISO1228 can be configured for both

sourcing and sinking type digital inputs with minimal

hardware change. Both serial SPI and parallel output

modes are available. Wire-break detection, field side

supply voltage monitoring and built-in CRC help

improve system reliability. In-built glitch filters and

integrated IEC-ESD and surge protection help to

achieve a robust design.

The ISO1228 operates over the logic supply range

of 1.71 V to 5.5 V, supporting 1.8-V, 2.5-V, 3.3-V,

and 5-V controllers. Field side output voltage range

supported is 8.5 V to 36 V in sink mode and 13 V

to 36 V in source mode. ISO1228 supports up to 1.5-

Mbps data rates passing a minimum pulse width of

667 ns for high-speed operation.