MLX90251 Datasheet, PDF (16/22 Pages) Melexis Microelectronic Systems – Programmable Linear Hall Effect Sensor

MLX90251
Programmable Linear Hall Effect Sensor
12.2 Programming the Sensor
To program the MLX90251 connection to V_DD, GND, and V_OUT is required. The device is placed into program
mode by increasing the supply voltage to the V_DD 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.
Figure 12.2-1 V_DD Programming Level
5.0V
2.5V
0V
Device
Decoded
Clock
V_OUT
Program Wave Form
Device
Decoded
Data
X
1
X
0
X
Figure 12.2-2 Tri-Level PTC
Note: External capacitors and resistors will effect the rise and fall times for the programming waveforms.
Program pulse timings may require adjustment for the application. The device can not be programmed if
MEMLOCK equals 1.
The EEPROM contents can be read from the device. This procedure, known as a read back, is done by
sending a read command and then measuring the supply current. To successfully read the EEPROM it must
be possible to measure the supply current to the device. The Melexis PTC hardware and software tools
contain built in functions for reading the EEPROM.
The MLX90251 can be programmed by using the PTC-04 programmer and the dedicated software tools. The
timing and voltage levels are controlled through the programming hardware and software. Further details can
be found in the MLX90251 software documentation.
3901090251
Rev 009
Page 16 of 22
Data Sheet
Nov/06