DATA SHEET
4.3. Temperature Compensation
The relationship between the temperature coefficient
of the magnet and the corresponding TC and TCSQ
codes for linear compensation is given in the following
table. In addition to the linear change of the magnetic
field with temperature, the curvature can be adjusted
as well. For this purpose, other TC and TCSQ combi-
nations are required which are not shown in the table.
Please contact Micronas for more detailed information
on this higher order temperature compensation.
The HAL805, HAL810, and HAL815 contain the same
temperature compensation circuits. If an optimal set-
ting for the HAL805/HAL810 is already available, the
same settings may be used for the HAL815.
4. Application Notes
4.1. Application Circuit
For EMC protection, it is recommended to connect one
ceramic 4.7 nF capacitor each between ground and
the supply voltage, respectively the output voltage pin.
In addition, the input of the controller unit should be
pulled-down with a 4.7 kOhm resistor and a ceramic
4.7 nF capacitor.
Please note that during programming, the sensor will
be supplied repeatedly with the programming voltage
of 12.5 V for 100 ms. All components connected to the
V
DD
line at this time must be able to resist this voltage.
V
DD
Temperature
Coefficient of
Magnet (ppm/K)
OUT
HAL815
4.7 nF
4.7 nF
GND
4.7 nF
4.7 kΩ
μC
TC
TCSQ
400
300
200
100
0
31
28
24
21
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
6
7
8
9
10
10
11
11
11
12
12
12
13
13
13
13
14
14
14
14
15
15
Fig. 4–1:
Recommended application circuit
4.2. Use of two HAL815 in Parallel
Two different HAL815 sensors which are operated in
parallel to the same supply and ground line can be
programmed individually. In order to select the IC
which should be programmed, both Hall ICs are inacti-
vated by the “Deactivate” command on the common
supply line. Then, the appropriate IC is activated by an
“Activate” pulse on its output. Only the activated sen-
sor will react to all following read, write, and program
commands. If the second IC has to be programmed,
the “Deactivate” command is sent again, and the sec-
ond IC can be selected.
−50
−90
−130
−170
−200
−240
−280
−320
−360
V
DD
OUT A & Select A
−410
−450
−500
−550
−600
10 nF
HAL 815
Sensor A
4.7 nF
HAL 815
Sensor B
OUT B & Select B
4.7 nF
GND
−650
−700
−750
Fig. 4–2:
Parallel operation of two HAL815
Micronas
Feb. 7, 2006; 6251-537-3DS
23
MICRONAS [ MICRONAS ]
