ASI4UC-G1-SR-7 ZMDI, ASI4UC-G1-SR-7 Datasheet - Page 17

• Manufacturer Part Number: ASI4UC-G1-SR-7
• Description: Interface - Specialized ASI
• Manufacturer: ZMDI

Specifications of ASI4UC-G1-SR-7

• Product Category: Interface - Specialized
• Rohs: yes
• Product Type: Actuator Sensor Interface IC
• Operating Supply Voltage: 16 V to 33.1 V
• Supply Current: 6 mA
• Maximum Power Dissipation: 850 mW
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: SSOP-28
• Minimum Operating Temperature: - 25 C

2.3.1.
In slave mode the ASI4U can work on two different communication channels, the AS-i channel and the IRD
channel. The AS-i channel is directly connected to AS-i Bus via the pins ASIP and ASIN. A receiver and a
transmitter unit are connected in parallel to the pins that allow fully bi-directional communication through ASIP
and ASIN.
The ASI4U is the first IC that supports floating operation of the AS-i receiver and transmitter (within certain
limits) in relation to IC ground. Thus far, the ASIN pin always had to be on the same potential like IC ground,
preventing full symmetrical input circuits with external coils. The following figures illustrate the new
functionality. If one compares the relation Z1 / Z2, which is a measure for symmetry of the AS-i module input
towards machine ground, it becomes obvious that the new circuit is more symmetrical since Z1 and Z2 are
more equal than in the conventional solution. Please note, that this is not a complete application circuit.
2.3.2.
Besides the AS-i communication channel the ASI4U can also operate on a second input channel, the so
called IRD Input Channel or Addressing Channel. In this mode the IRD pin is input for an AS-i signal in
Manchester-II-coded format. The signal can either be an AC-current signal generated by a photo diode or a
5V-CMOS signal. The IC automatically detects the type of the signal and switches the input path accordingly.
Output pin in IRD communication mode is LED1. It transmits the slave response as inverted Manchester-II-
coded AS-i signal. The red LED, which is normally connected to LED1, can form the response transmitter in
an optical communication system or LED1 can be directly connected to some external circuitry.
Activation of the IRD communication channel is achieved by a so called magic sequence that is sent in
advance of the desired communication. The construction of a magic sequence is described in detail in chapter
3.3 Addressing Channel Input IRD on page 28. The IRD communication mode is basically left by IC reset,
except in one special case that is also described in that
2.3.3.
The ASI4U features a 4-bit wide parameter port and a related parameter strobe signal pin PST. There is a
defined phase relation between a parameter output event, the parameter input sampling and the activation of
the PST signal. Thus it can be used to trigger external logic or a micro controller to process the received
parameter data or to provide new input data for the AS-i slave response.
AS-i Complete Specification V3.0 newly defines a bidirectional mode for parameter data. The ASI4U supports
this feature that can be activated by special E²PROM setting.
See chapter 3.6 Parameter Port and PST on page 32 for further details.
Data Sheet
January 30, 2012
Figure 4: Conventional application of AS-i IC
ASI+
ASI-
ASI4U / ASI4U-E
Spec. 3.0 Com
AS-i communication channel
IRD communication channel
Parameter Port Pins
Z1
with one external coil
Z2
© 2012 Zentrum Mikroelektronik Dresden AG — Rev. 2.1
All rights reserved. The material contained herein may not be reproduced, adapted, merged, translated, stored, or used without
the prior written consent of the copyright owner. The information furnished in this publication is PRELIMINARY and subject to
changes without notice.
pliant Universal AS-I IC
Slave
GND
AS-i
IC
Load
chapter.
ASI+
ASI-
Figure 5: Newly supported application of AS-i IC
Z1
with two external coils
Z2
GND
Slave
AS-i
IC
Load
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