SAP5SD-A-G1-T Datasheet, PDF (14/63 Pages) List of Unclassifed Manufacturers – Universal Actuator-Sensor Interface IC

SAP5S / SAP51
Universal Actuator-Sensor Interface IC
2 Basic Functional Description
2.1. Functional Block Diagram
U5R
Power
Supply
Thermal
Protection
CDC
Electronic
Inductor
Power
Fail Detector
APF
LTGP
LTGN
pos
Receiver
neg
UART
Transmitter MAN
Main
State
Machine
Param
Offset
I/O
Data
Offset
I/O
LED
Output
DSTB
I/O
PSTB
Output
PFAULT
Input
UOUT
P3 ... P0
D3 ... D0
LED2, LED1
DSTBn
PSTBn
PFAULT
OSC1
OSC2
OSCILLATOR
PLL
clk
EEPROM
Figure 3: Functional Block Diagram
Following device functions are associated with the different blocks of the IC:
RECEIVER
TRANSMITTER
The receive block converts the analog telegram waveform from the AS-i bus to a digital
pulse coded signal that can be processed further by a digital UART circuit.
The RECEIVE block is directly connected to the AS-i line pins LTGP and LTGN. It
converts the differential AS-i telegram to a single ended signal and removes the DC offset
by high pass filtering. To adapt quickly on changing signal amplitudes in telegrams from
different network users, the amplitude of the first telegram pulse is measured by a 3 bit
flash ADC and the threshold of a positive and a negative comparator is set accordingly to
about 50% of the measured level. The comparators generate the P-Pulse and N-Pulse
signals.
The transmit block transforms a digital response signal to a correctly shaped send current
signal which is applied to the AS-i bus. Due to the inductive network behavior of the
network the changing send current induces voltage pulses on the network line that overlay
the DC operating voltage. The voltage pulses shall have sin²-wave shapes. Hence, the
send current shape must follow the integral of the sin²-wave function.
Data Sheet
July 17, 2012
© 2012 Zentrum Mikroelektronik Dresden AG — Rev. 3.1
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.
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