A3241 데이터 시트보기 (PDF) - Allegro MicroSystems
부품명
상세내역
제조사
A3241 Datasheet PDF : 12 Pages
| |||
A3241 and A3242
Chopper-Stabilized Unipolar Hall Effect Switches
Functional Description
Operation
The output of these devices switches low (turns on) when a
magnetic field (south polarity) perpendicular to the Hall sen-
sor exceeds the operate point threshold, BOP. After turn-on, the
output voltage is VOUT(SAT). The output transistor is capable of
sinking current up to the short circuit current limit, IOM, which
is a minimum of 30 mA. When the magnetic field is reduced
below the release point, BRP, the device output goes high (turns
off). The difference in the magnetic operate and release points is
the hysteresis, Bhys, of the device. This built-in hysteresis allows
clean switching of the output even in the presence of external
mechanical vibration and electrical noise.
Powering-on the device in the hysteresis region, less than BOP
and higher than BRP, allows an indeterminate output state. The
correct state is attained after the first excursion beyond BOP or
BRP.
Applications
It is strongly recommended that an external bypass capacitor be
connected (in close proximity to the Hall sensor) between the
supply and ground of the device to reduce both external noise
and noise generated by the chopper stabilization technique. As is
shown in Panel B of figure 1, a 0.1μF capacitor is typical.
Extensive applications information on magnets and Hall-effect
sensors is available in:
• Hall-Effect IC Applications Guide, AN27701,
• Hall-Effect Devices: Gluing, Potting, Encapsulating, Lead
Welding and Lead Forming, AN27703.1
• Soldering Methods for Allegro’s Products – SMT and Through-
Hole, AN26009
All are provided in Allegro Electronic Data Book, AMS-702 and
the Allegro Web site: www.allegromicro.com
(A)
V+
VCC
0
B– 0
BHYS
VOUT(SAT)
B+
(B)
VS
VCC
CBYP
0.1 μF
A324x
VOUT
GND
RLOAD
Sensor Output
Figure 1: Switching Behavior of Unipolar Switches. In Panel A, on the horizontal axis, the B+ direction indicates increasing south polarity
magnetic field strength, and the B– direction indicates decreasing south polarity field strength (including the case of increasing north
polarity). This behavior can be exhibited when using a circuit such as that shown in panel B.
A3241-DS, Rev. 2
Allegro MicroSystems, Inc.
8
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com
Share Link: 