MLX16303 Datasheet, PDF (11/20 Pages) Melexis Microelectronic Systems – Bi-directional Remote Sensor Unit Interface

MLX16303
Bi-directional Remote Sensor Unit Interface
5. General Description
VS (supply Voltage VDD2)
The IC and the external units are powered via the VS pin .VS is connected to a powerunit IC output
voltage.
VP (programming Voltage VDD1)
For the programming of the remote sensor the MLX16303 needs a higher voltage than VS. This voltage is
named VP.
VP is connected to the battery via a reverse polarity protection diode (KL15). The VP pin may not source
current under all conditions, especially after battery cut off.
VDD (5V Voltage)
Additional to the VS and VP MLX16303 needs a low current 5V voltage for the digital part and reference
use.
This voltage is named VDD.
GND
The design has two GND pins.
RTRIP (External Current Reference Resistor)
The trip point is established by setting a reference current via an external reference resistor connected to
ground. This reference current is needed for the current threshold of the current level-comparators. The
current threshold can change with different resistors. This trip point is common for both channels.
OUT0, OUT1
OUTx makes a smoothed, very slow changing supply voltage for the external remote units according to
the given electrical characteristic and monitors the output current. Each OUTx stage has a short circuit,
over voltage and over temperature protection. The OUTx voltage can be switched on and off via SPI.
There are two modes possible:
Programming mode:
The OUTx voltage can be modulated by the bi-directional remote unit interface IC between two defined
voltage ranges.
Non Programming mode:
No communication to the remote unit is possible.
The data transmission from the bi-directional remote unit interface IC to the external remote unit is only
enabled during the programming mode. The programming mode is enabled and disabled by a SPI
command.
RETURN0, RETURN1
The RETURNx pins make a low resistive connection to GND via a switched open collector transistor.
RETURNx will switch on if OUTx is switched on via SPI and vice versa.
SSIO0, SSIO1 (SideSatelliteInOut)
The SSIOx pins are bidirectional and have so multiple function.
In the non-programming mode (normal operation) the current at the pin OUTx is sensed and logical
evaluated as high or low current level. In this operation the pin is used as an output pin. At high current at
OUTx, SSIOx switches to low level (CMOS-compatible) and vice versa.
In the programming mode the SSIOx pins are used as input pins. Logical (CMOS-compatible) PWM
pulses from a microcontroller modulate the OUTx between two defined voltage ranges (high and low). At
3901016303
Rev. 004
Page 11 of 20
Data Sheet
Jun/04