ATS674 Allegro MicroSystems, ATS674 Datasheet - Page 10

• Manufacturer Part Number: ATS674
• Description: (ATS673 / ATS674) Self-Calibrating TPOS Gear Tooth Sensor Optimized
• Manufacturer: Allegro MicroSystems

ATS673 and
ATS674
TPOS (True Power-On State) Operation
Under specified operating conditions, the devices are guaran-
teed to attain a specified output voltage polarity at power-on, in
relation to the target feature nearest the device at that time. Both
devices offer the options of either high or low polarity over ini-
tial tooth or valley. This polarity also applies throughout device
operation.
Start-Up Detection
These devices provide an output polarity transition at the first
mechanical edge after power-on.
Undervoltage Lockout
When the supply voltage falls below the undervoltage lockout
level, V
remains in that state until the voltage level is restored to to the
V
have no effect until voltage is restored. This prevents false sig-
nals caused by undervoltage conditions from propagating to the
output of the sensor.
CC
operating range. Changes in the target magnetic profile
CCUV
, the device switches to the OFF state. The device
Self-Calibrating TPOS Gear Tooth Sensor Optimized
V
Figure 5. Power Supply Protection Typical Circuit
S
C
0.1 μF
BYPASS
for Automotive Cam Sensing Applications
3
TEST
ATS673/674
VCC
GND
1
4
Power Supply Protection
The ATS673 and ATS674 contain an on-chip regulator and can
operate over a wide range of supply voltage levels. For applica-
tions using an unregulated power supply, transient protection
must be added externally. For applications using a regulated
supply line, EMI and RFI protection may still be required. The
circuit shown in figure 5 is the basic configuration required for
proper device operation. Contact Allegro field applications engi-
neering for information on the circuitry required for compliance
to various EMC specifications.
Internal Electronics
These devices contain a self-calibrating Hall effect IC that
provides a Hall element, a temperature compensated ampli-
fier, and offset cancellation circuitry. The IC also contains a
voltage regulator that provides supply noise rejection over the
operating voltage range. The Hall transducers and the electron-
ics are integrated on the same silicon substrate by a proprietary
BiCMOS process. Changes in temperature do not greatly affect
this device due to the stable amplifier design and the offset rejec-
tion circuitry.
VOUT
2
R
PU
Sensor Output
115 Northeast Cutoff, Box 15036
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 [phone]
www.allegromicro.com
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