A1180, A1181,
A1182, and A1183
Sensitive Two-Wire Field-Programmable
Chopper-Stabilized Unipolar Hall Effect Switches
Functional Description
Operation
The output, ICC, of the A1180 and A1182 devices switch low
after the magnetic field at the Hall sensor exceeds the oper-
ate point threshold, BOP. When the magnetic field is reduced to
below the release point threshold, BRP, the device output goes
high. The differences between the magnetic operate and release
point is called the hysteresis of the device, BHYS. This built-
in hysteresis allows clean switching of the output even in the
presence of external mechanical vibration and electrical noise.
The A1181 and A1183 devices switch with opposite polarity for
similar BOP and BRP values, in comparison to the A1180 and
A1183 (see figure 1).
I+
ICC(H)
I+
ICC(H)
0
B–
BHYS
ICC(L)
B+
0
B–
BHYS
ICC(L)
B+
(A) A1180 and A1182
(B) A1181 and A1183
Figure 1. Alternative switching behaviors are available in the A118x device family. 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).
Allegro MicroSystems, Inc.
7
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
www.allegromicro.com