ISO1228 Eight-Channel Isolated Digital Input with Current Limit and Diagnostics

1 Features

• Configurable IEC 61131-2 eight Type 1/3 or four

Type 2 Isolated Digital Inputs

• Low Power and Heat Dissipation

– Selectable input current limit

– Fieldside LED drivers using input current

• Configurable sinking or sourcing type inputs

• Wire-break detection in sink mode

• Integrated field-side power loss detection

• 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): 75kV/µs

• VCC1 Logic supply voltage range: 1.71V to 5.5V

• AVCC field supply voltage range (sink mode): 8.5V

to 36V

• AVCC field supply voltage range (source mode):

13V to 36V

• 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

EN IEC 60747-17 (VDE 0884-17)

– 3000-VRMS Isolation for 1 Minute per UL 1577

– IEC 62368-1, IEC 61010-1 Certifications

– 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 24V

digital input receiver, configurable to IEC 61131-2

Type 1, and 3 characteristics or four-channel

Type 2 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 either

sourcing or sinking type digital inputs with minimal

hardware change. Both serial SPI and parallel output

modes are available. Wire-break detection, fieldside

supply monitoring and built-in CRC across barriers

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

1.71V to 5.5V, supporting 1.8V, 2.5-V, 3.3V, and 5V

controllers. Field side output voltage range supported

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

source mode. ISO1228 supports up to 1.5Mbps data

rates passing a minimum pulse width of 667ns for

high-speed operation.

Device Information

PART

NUMBER

PACKAGE(1) PACKAGE SIZE(2)

BODY SIZE

(NOM)

ISO1228

SSOP (38)

DFB

9.9mm × 6.0mm

9.9mm ×

3.90mm

(1)

For all available packages, see the orderable addendum at

the end of the data sheet.

(2)

The package size (length × width) is a nominal value

andincludes pins, where applicable.

INx

R

THR

LEDx

24V

Field GND

Sensor

VCC1

OUTx/SPI

GND

R

PAR

AVCC

AVSS

R

ILIM

R

SURGE

C

SURGE

IN1F

V24V

(8.5V-36V)

C

FIL

C

IN

0V

Current Limit Se ng for

all channels

Host Controller

Sink Type

INx

R

THR

LEDx

24V

Field GND

Sensor

VCC1

OUTx/SPI

GND

R

PAR

AVCC

AVSS

R

ILIM

C

SURGE

IN1F

V24V

(13V-36V)

C

FIL

C

IN

0V

Current Limit Se ng for

all channels

Host Controller

Source Type

ISO1228

SLLSFN5A – JUNE 2023 – REVISED FEBRUARY 2024

An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,

intellectual property matters and other important disclaimers. PRODUCTION DATA.