A1140 Allegro MicroSystems, A1140 Datasheet - Page 6

• Manufacturer Part Number: A1140
• Description: Sensitive Two-Wire Chopper-Stabilized Unipolar Hall-Effect Switches
• Manufacturer: Allegro MicroSystems

Operation
The output, I
after the magnetic fi eld at the Hall sensor exceeds the oper-
ate point threshold, B
below the release point threshold, B
high. The differences between the magnetic operate and release
point is called the hysteresis of the device, B
Figure 1. Alternative switching behaviors are available in the A114x device family. On the horizontal axis, the B+ direction indicates
increasing south polarity magnetic fi eld strength, and the B– direction indicates decreasing south polarity fi eld strength (including the
case of increasing north polarity).
A1140-DS
CC
Sensitive Two-Wire Chopper-Stabilized Unipolar Hall Effect Switches
, of the A1140 and A1142 devices switch low
I+
0
B–
OP
(A) A1140, A1142
. When the magnetic fi eld is reduced to
B
HYS
RP
, the device output goes
HYS
B+
. This built-
I
I
CC(H)
Functional Description
CC(L)
A1140/41/42/43
in hysteresis allows clean switching of the output even in the
presence of external mechanical vibration and electrical noise.
The A1141 and A1143 devices switch with opposite polarity for
similar B
A1142 (see fi gure 1).
OP
and B
I+
0
RP
B–
values, in comparison to the A1140 and
(B) A1141, A1143
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]
www.allegromicro.com
B
HYS
B+
I
I
CC(H)
CC(L)
6