MLX90314_12 Datasheet, PDF (7/28 Pages) Melexis Microelectronic Systems – Programmable Sensor Interface

MLX90314
Programmable Sensor Interface
Unique Features
Customization
Melexis can customize the MLX90314 in both
hardware and firmware for unique requirements. The
hardware design provides 64 bytes of RAM, 3 kbytes
of ROM, and 48 bytes of EEPROM for use by the
firmware.
Special Information
The output of the sensor bridge is amplified via offset
and gain amplifiers and then converted to the correct
output signal form in one of the output stages.
The sensitivity and offset of the analog signal chain
are defined by numbers passed to the DAC interfaces
from the microcontroller core (GN[9:0] and OF[9:0]).
The wide range of bridge offset and gain is
accommodated by means of a 2-bit coarse adjustment
DAC in the offset adjustment (CSOF[1:0]), and a
similar one in the gain adjustment (CSGN[2:0]). The
signal path can be directed through the processor for
digital processing. Two I/O pins are available for
analog inputs or digital outputs. These pins can be
used for alarms on various points on the analog signal
path and built-in or external temperature values.
Programming and Setup
The MLX90314 needs to have the compensation
coefficients programmed for a particular bridge
sensor to create the sensor system.
Programming the EEPROM involves some
minimal communications interface circuitry,
Melexis’ setup software, and a PC. The
communications interface circuitry is available in
a de ve lopm ent b oar d. T his circuitr y
communicates with the PC via a standard RS-
232 serial communications port.
Table 2. Absolute Maximum Ratings
Supply voltage (ratiometric) VDD Max
6V
Supply voltage (ratiometric) VDD Min
4.5V
Supply voltage (operating), VDD1 Max 35V
Reverse voltage protection
-0.7V
Supply current, Current Mode, I_DD
Supply current, Voltage Mode, I_DD
3.5mA
4.5mA
Output current, I_VMO
Output current (short to V_DD), I_SCVMO
Output current (short to V_SS), I_SCVMO
8mA
100mA
8mA
Output voltage, V_VMO
Power dissipation, P_D
Operating temperature range, T_A
Storage temperature range, T_S
Maximum junction temperature, T_J
+11V
71mW
-40 to +140°
-55 to +150°
150°C
Cross Reference
There are no known devices which the MLX 90314
can replace.
ESD Precautions
Observe standard ESD control procedures for CMOS
semiconductors.
3901090314
Rev 008
Page 7
Apr/12