ISOFACE™ Digital Input ICs

The ISO1I81xT digital input product family is a intelligent system solution offering robust galvanic isolation between the µC on the “control side” and the 24V factory floor environment, frequently referred to as the “process side”.

Complete integration

The ISOFACE™ ISO1I81xT product family ISO1I811T and  ISO1I813T of galvanically isolated 8-channel digital input ICs sample input data from digital sensors and switches. The digital input ICs can be directly connected to digital inputs like sensors or switches and the microcontroller or bus-ASIC. Robust galvanic isolation is integrated.

8 input channels

Up to 8 inputs according to IEC61131-2 (Type 1/2/3) can be connected per IC. The precise characteristic of the current sink of the IC’s inputs reduces the power dissipation per channel by a factor of up to 2.5-times compared to solutions using resistors and opto-couplers. In consequence, more compact designs of input card solutions become possible with ISOFACE™.

Deglitching filters

To improve EMI robustness of the system solution, the 8 input channels are equipped with adjustable deglitching filters. In case of the ISO1I811T, jumpers on the PCB can be used to select one of the four possible settings. The ISO1I813T allows to individually program the filter setting for each of the channels. Bypass mode, i.e. zero filter time, is offered with both types.

High sampling speeds

The ISOFACE™ digital input ICs support sampling speeds of up to 500kHz per input channel, substantially exceeding the speed of solutions using opto-couplers. Therefore, they are ideally suited for high-precision or high-speed applications like bottling machines or paper and printing industries.

Time-stamping

A feature only available with the ISO1I813T is the capability to synchronously capture the input signals from multiple input ICs. This is of particular practical relevance when an isochronous time-stamp of the status of a complex machine or equipment is required.

Flexible interfaces

The microcontroller or bus-ASIC can be connected either via a high-speed SPI Interface or using a parallel 8-bit interface to the ICs. To support very compact system designs daisy-chaining of multiple ISOFACE™ digital input ICs is supported. To ensure uncompromised data-transfer with the microcontroller the ISO1I813T supports CRC-checking of the serial communication.

Galvanic isolation

The ISOFACE™ digital input ICs offer a robust integrated galvanic isolation of 500V _AC (EN60664-1, UL508). When compared with alternative solutions, ISOFACE™ digital input ICs enable up to four times more channels on the same PCB area. This high level of integration density combined with the low power consumption is a key enabler for highly compact industrial control products.

Comprehensive diagnostics

The diagnostic capabilities of the ISO1I813T includes the detection of a wire-break between the IC`s inputs and the sensors or switches connected to it. When such error is detected, the microcontroller or bus-ASIC can identify the individual channel. Furthermore, the device’s supply voltage (V _bb missing voltage) is being monitored. When V _bb missing voltage is diagnosed, the error pin indicates that the input data collected is not valid.

The ISO1I813T can even issue a pre-warning, if V _bb is falling below a pre-warning limit (V _bb under-voltage). This allows, for example, the system to assume a different mode of operation or to safely shut down. Monitoring wire-break and Vbb greatly improves the factory level maintenance thus providing a significant contribution to minimize costly un-scheduled machine down-times.

Key features:

• Complete system integration (digital sensor or switch input, galvanic isolation and intelligent microcontroller or bus-ASIC interface)
• 8-channel input according to IEC61131-2 (Type 1/2/3) 
• Integrated galvanic isolation 500V AC (EN60664-1, UL508) 
• 3V SPI and parallel microcontroller interface 
• Adjustable deglitching filters
• Up to 500kHz sampling frequency 
• Wire-break detection 
• V_bbunder-voltage detection
• Package: TSSOP 8x12.5mm