MLX90255LUF-2 MELEXIS [Melexis Microelectronic Systems], MLX90255LUF-2 Datasheet - Page 4

• Manufacturer Part Number: MLX90255LUF-2
• Description: Relative Integrated Pressure Sensor
• Manufacturer: MELEXIS [Melexis Microelectronic Systems]

This chip integrates a pressure sensor and the associated signal conditioning on the same die. The
supply voltage V
A chopped instrumentation stage amplifies the differential output signal of the sensor. The gain of this
amplifier can be adjusted with 3 bits. The input stage is followed by a differential to single-ended
conversion. The reference voltage for this stage is generated by a 10 bit DAC and varies linearly with
temperature in order to perform the offset and offset drift compensation. A digital hardware multiplier
calculates this compensation. The temperature signal, serving as input for this multiplier, is generated
from the ADC of the output signal of the internal temperature sensor.
The chopped signal is demodulated with a switched capacitor stage. The buffered output serves as
reference for a 10 bit DAC to perform the span and span drift compensation. The DAC is controlled by the
digital part.
Finally the signal is given out by a class AB rail-to-rail amplifier capable of sourcing and sinking large
currents.
A 3-point temperature and 2-point pressure calibration is required (room temperature, a low temperature
and a high temperature), to achieve an error less than ±1% over the complete pressure and temperature
range (the output error is referred to the output span).
PTC (Programming Through Connector) protocol is used to perform calibration.
Diagnostic Limits
Diagnostic of broken sensor: The output will be forced to ground (or a very low level) when the sensor
membrane breaks.
Diagnostic of broken wires: The output will be forced to ground (or a very low level) when the supply wire
breaks, even when a pull-up is still connected to the output pin.
The output will be forced to the supply voltage (or a very high level) when the ground wire breaks, even
when a pull-down is still connected to the output pin.
Output Protection
The output is protected against short-circuits at either battery terminals. The output can handle voltages
between -0.5V and 16V (independent of supply voltage).
Memlock Function
The memory consists of ZAP cells. When all calibration parameters are programmed, the chip can be
locked. This to avoid unwanted data to be written into the memory cells.
Once the chip is locked in a normal application, it is not possible to unlock.
Clamping Levels
The user can enable the clamping of the output to ensure that the output can not enter the fault band in
normal application.
3901090257
Rev. 006
5. General Description
6. Unique Features
DD
directly supplies the pressure sensor.
Page 4 of 9
Relative Integrated Pressure Sensor
MLX90257
Data Sheet
Mar/08