MLX92241 Datasheet, PDF (12/16 Pages) Melexis Microelectronic Systems – 2-Wire Hall Effect Switch

MLX92241-AAA
2-Wire Hall Effect Switch
8 Application Information
8.1 Typical Automotive Application Circuit
ECU
V_CC
C1
10nF
VH_SENSE
R_SENSE
100
MLX92221 / 41
VDD
TEST
GND
Notes:
1. For proper operation, a 10nF bypass capacitor should be
placed as close as possible to the V_DD and ground(GND) pin.
For complete emissions protection a C1 = 68nF is
recommended.
2. The TEST pin is to be left open or connected to GND.
8.2 Automotive and Harsh, Noisy
Environments Application Circuit
ECU
8.3 Strobing V_DD application (used for
reduced self-heating)
ECU
V_CC
D1
(optional,
see Note 2)
VH_SENSE
R_SENSE
100
DZ1
(optional,
see Note 3)
C1
68nF
MMLLXX9922224211 / 41
VDD
TEST
GND
Notes:
1. For proper operation, a 10nF to 100nF bypass capacitor should be placed as close
as possible to the VDD and ground pin.
2. The device could tolerate negative voltage down to -24V, so if negative transients
over supply line VPEAK< -29V are expected, usage of the diode D1 is recommended.
Otherwise only RSENSE is sufficient.
When selecting the resistor RSENSE, three points are important:
- the resistor has to limit IDD/IDDREV to 50mA maximum
- the resistor has to withstand the power dissipated in both over voltage
conditions (VRSENSE2/RSENSE)
- the resulting device supply voltage VDD has to be higher than VDD min
(VDD = VCC – RSENSE.IDD)
3. The device could tolerate positive supply voltage up to +27V (until the maximum
power dissipation is not exceeded), so if positive transients over supply line with
VPEAK> 32V are expected, usage a zener diode DZ1 is recommended. The RSENSE-DZ1
network should be sized to limit the voltage over the device below the maximum
allowed.
VCC
VHSENSE
RSENSE
100
C1
68nF
MLX92221 / 41
VDD
TEST
GND
VDD
12 V
South Pole
weak South or B = null
ON phase
I DD
(1ms)
OFF phase
(1s)
t
I _ONtyp
I _OFFtyp
t ON
Valid IDD
state
Valid IDD
state
t ON
t
Notes :
1. Given strobe timing is exemplary only.
2. ^{For proper operation,} a 10nF to 100nF bypass capacitor should be placed as
close as possible to the V_DD and ground pin.
390109224100 Rev. 1
Page 12 of 16
June/13