MLX90320_12 Datasheet, PDF (19/33 Pages) Melexis Microelectronic Systems – Automotive sensor interface

MLX90320
Automotive sensor interface
6.5 Programming the MLX90320 through the output pin
Communicating with the MLX90320 only requires a limited amount of interface circuitry, software and a
computer. Melexis provides a communication equipment and belonging software such that the customer is able
to start communicating with the chip in a matter of minutes.
The output pin acts as analog output pin and as communication pin.
The drive stage of a class AB amplifier is connected to that pin to output analog signal.
For the communication the output will be sink/source current source.
Through a short circuit detection, the ASSP knows that the user requests the pin for communication.
6.5.1 Overview
When the user wants to communicate with the MLX90320, communication must be requested.
This can be achieved by short-circuiting the output pin to ground and supply level.
The ASSP detects this short and after a delay time, the same output pin turns into a half-duplex digital
communication channel.
6.5.2 Communication Initialization Request
When a new chip is supplied with 5V, before sending a first command to this chip, a power reset of 1.5ms +/-
30% is required. For the further commands with the same chip the power reset is not needed anymore.
After a communication initialization request, a delay of at least 10msec has to be taken before sending a
communication request.
3901090320
Rev 007
Page 19 of 33
Data Sheet
Feb/12