Brief Description
The ASI4U is a next-generation CMOS integrated
circuit for AS-i networks. This low-level field bus AS-i
(Actuator Sensor Interface) was designed for easy,
safe, and cost-effective interconnection of sensors,
actuators, and switches. It transports both power
and data over the same two-wire unshielded cable.
The ASI4U is used as part of a master or slave node
and functions as an interface to the physical bus. It
provides the power supply, physical data transfer,
and communication protocol handling. The ASI4U is
fully compliant with the AS-Interface Complete
Specification V3.0. It is function and pin compatible
with the A²SI IC.
All configuration data are stored in an internal
EEPROM that can be easily programmed by a
stationary or handheld programming device. The
special AS-i safety option assures short response
times for security-related events

Features
• Compliant with AS-Interface Complete Specification V3.0
• Universal application: slaves, masters, repeaters,
and bus-monitors
• Floating AS-i transmitter and receiver for highly
symmetrical high-power applications
• On-chip electronic inductor with current drive
capability of 55 mA
• Two configurable LED outputs to support all
AS-Interface Complete Specification V3.0 status
indication modes
• Several data pre-processing functions, including
configurable data input filters and bit-selective
data inverting
• Additional addressing channel for easy wireless
module setup
• Support of 8 and 16 MHz crystals by automatic
frequency detection
• Special AS-i safety option
• Clock watchdog for high system security