ADVANCE INFORMATION
HAL815
4. Application Notes
4.3. Temperature Compensation
4.1. Application Circuit
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.
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 V for 100 ms. All components connected to the
VDD line at this time must be able to resist this voltage.
The HAL 800 and HAL 815 contain the same tempera-
ture compensation circuits. If an optimal setting for the
HAL 800 is already available, the same settings may
be used for the HAL 815.
V
DD
Temperature
TC
TCSQ
Coefficient of
Magnet (ppm/K)
OUT
GND
HAL815
µC
400
300
31
28
24
21
18
17
16
15
14
13
12
11
10
9
6
4.7 nF
7
4.7 nF
4.7 nF
4.7 kΩ
200
8
100
9
Fig. 4–1: Recommended application circuit
0
10
10
11
11
11
12
12
12
13
13
13
13
14
14
14
14
15
15
−50
4.2. Use of two HAL 815 in Parallel
−90
Two different HAL 815 sensors which are operated in
parallel to the same supply and ground line can be pro-
grammed individually. In order to select the IC which
should be programmed, both Hall ICs are inactivated
by the “Deactivate” command on the common supply
line. Then, the appropriate IC is activated by an “Acti-
vate” pulse on its output. Only the activated sensor will
react to all following read, write, and program com-
mands. If the second IC has to be programmed, the
“Deactivate” command is sent again, and the second
IC can be selected.
−130
−170
−200
−240
−280
−320
−360
−410
−450
−500
−550
−600
−650
−700
−750
V
DD
8
OUT A & Select A
OUT B & Select B
7
6
HAL 815
Sensor A
HAL 815
Sensor B
10 nF
5
4
4.7 nF
4.7 nF
GND
3
Fig. 4–2: Parallel operation of two HAL 815
2
1
Micronas
17
MICRONAS [ MICRONAS ]
