3054
MULTIPLEXED
TWO-WIRE
HALL-EFFECT SENSOR ICs
SENSOR LOCATION
FUNCTIONAL BLOCK DIAGRAM
(±0.005” [0.13 mm] die placement)
1
BUS
ACTIVE AREA DEPTH
0.015"
0.090"
0.38 mm
2.29 mm
NOM
REG
COMP
COMP
0.073"
1.85 mm
RESET
CLOCK
CMOS LOGIC
SWITCH IN
(OPTIONAL)
3
A
BRANDED
SURFACE
1
2
3
2
GROUND
Dwg. FH-009
Dwg. MH-002-10A
DEFINITION OF TERMS
Sensor Address
Sensor Quiescent Current Drain (IQ)
Each bus sensor has a factory-specified predefined
address. At present, allowable sensor addresses are
integers from 01 to 30.
The current drain of bus sensors when active but not
addressed. IQH is the quiescent current drain when the
sensor is not addressed and is at VH IQL is the quiescent
current drain when the sensor is not addressed and is at
LOW-to-HlGH Clock Threshold (VCLH
)
VL. Note that IQL is greater than IQH
.
Minimum voltage required during the positive-going
transition to increment the bus address and trigger a
diagnostic response from the bus sensors. This is also
the maximum threshold of the on-chip comparator that
Diagnostic Phase
Period on the bus when the address voltage is at VH.
During this period, a correctly addressed sensor responds
by increasing its current drain on the bus. This response
from the sensor is called the diagnostic response and
the bus current increase is called the diagnostic current.
monitors the supply voltage, VBUS
.
HlGH-to-LOW Threshold (VHL)
Maximum voltage required during the negative-going
transition to trigger a signal current response from the bus
sensors. This is also the maximum threshold of the
on-chip comparator that monitors the supply voltage,
Signal Phase
Period on the bus when the address voltage is at VL.
During this period, a correctly addressed sensor that
detects a magnetic field greater than the magnetic oper-
ate point, BOP, responds by maintaining a current drain of
IS on the bus. This response from the sensor is called the
signal response and the bus current is called the signal
current.
VBUS
.
Bus HIGH Voltage (VH)
Bus HIGH voltage during addressing. Voltage should
be greater than VCLH
.
Sensor Address Response Current (IS)
Address LOW Voltage (VL)
Sensor current during the diagnostic and the signal
responses of the bus sensor. This is accomplished by
enabling an internal constant-current source.
Bus LOW voltage during addressing. Voltage should
be greater than VRST and less than VCHL
.
Bus Reset Voltage (VRST
)
Voltage level while resetting sensors.
ALLEGRO [ ALLEGRO MICROSYSTEMS ]
