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MLX90251_12 Datasheet, PDF (16/20 Pages) Melexis Microelectronic Systems – Programmable Linear Hall Effect Sensor
MLX90251
Programmable Linear Hall Effect Sensor
12 Applications Information
12.1 Application Circuits – VA-package
Pin 2, TEST, is not used in applications. For EMC protection it is recommended to connect pin 2 to pin 3,
Ground, as close as possible to the device pins. The values for capacitors, C1 and C2, can be adjusted to
satisfy ESD and EMC requirements according to the environment. Ceramic capacitors are recommended for
use in the application. However for stable operation, the global output capacitor (C2 + C3) should not be
higher than 150nF.If higher capacitors (due to special ESD or EMC requirements) or special circuit
configurations are requested, please contact Melexis.
The MLX90251 can operate with a high impedance load and C2, a load resistor is not required.
Figures 12.1-1…12.1-2 Application Circuits
A voltage of 9V is required on VDD for programming. All additional components connected to VDD must be
able to withstand the voltage. The MLX90251 is designed for operation with a stable 5V supply. If fast
voltage transients occur additional filtering may be required.
12.2 Programming the Sensor
To program the MLX90251 connection to VDD, GND, and VOUT is required. The device is placed into program
mode by increasing the supply voltage to the VDD program level. In program mode data is clocked into the
device through the output pin using the Melexis tri-level PTC protocol. The clock and data are integrated into
one serial data stream, eliminating the need for a dedicated clock signal. The data is clocked at the leading
edge of each bit.
5.0V
2.5V
0V
Device
Decoded
Clock
VOUT
Program Wave Form
Figure 12.2-1 VDD Programming Level
Device
Decoded
Data
X
1
X
0
X
Figure 12.2-2 Tri-Level PTC
3901090251
Rev 012
Page 16 of 20
Data Sheet
Oct/2012