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Feature Sheet, Rev.1.0, April 10, 2002
ZMD AG
A2SI
Advanced AS-Interface IC
Description
A2SI is a monolithic CMOS integrated circuit certified for AS-i (Actuator Sensor-interface) networks. AS-i
networks are intended for industrial automation.
The main advantage of AS-i solutions is that actuators and sensors are connected using a two-wire unshielded
cable that is easy to install. This cable transports both power and information/data.
AS-i network communication is based on the master-slave principle. The network can be extended (to cable
lengths greater than 100m) by using the A2SI in the repeater mode configuration. A2SI is furthermore used as
slave interface to sensors / actuators and as master interface.
AS-i is a standard for the automation industry based on IEC 62026-2 and EN 50295.
The device is available in a 28-pin SSOP (5,3 mm) package.
Features
AS-i Complete Specification V2.11 compliant
Integrated EEPROM
Additional addressing channel using an opto-electronic interface
Extended address mode operation as programmable option (up to 62 slaves)
High impedance AS-i line input, additional pins for further impedance optimizations
DC voltage output, approximately 24 volts, not stabilized
5 volt DC voltage output, stabilized, CMOS logic can be supplied directly (e.g. μC)
LED status indicator output (compliant with the standard indication recommendation)
Integrated watchdog
Temperature range -25°C to + 85°C
Block Diagram
RECEIVE
TRANSMIT
ELECTRONIC
INDUCTOR
POWER
SUPPLY
OSCILLATOR
4
4
4
DIGITAL
LOGIC
THERMAL
PROTECTION
A
2
SI
GND2
GND1
ASI+
ASI–
8 MHz
DOx
DIx
DSR
PST
Px
FID
LED
IRD
GND
0V
U
IN
U
OUT
U5R
U5RD
OSC1/2
CAP
ASIP
ASIN
10 F
2.2 F
5V
24V
POWERFAIL
DETECTION
IRD
AMP
C
CAP
R
CAP