A1120ELHLT-T Allegro Microsystems Inc, A1120ELHLT-T Datasheet - Page 10

• Manufacturer Part Number: A1120ELHLT-T
• Description: IC SWITCH UNIPOLAR 3V SOT-23W
• Manufacturer: Allegro Microsystems Inc
• Type: Unipolar Switchr

Specifications of A1120ELHLT-T

• Sensing Range: 50G Trip, 5G Release
• Voltage - Supply: 3 V ~ 24 V
• Current - Supply: 4mA
• Current - Output (max): 60mA
• Output Type: Digital, Open Collector
• Features: High Temperature
• Operating Temperature: -40°C ~ 85°C
• Package / Case: SOT-23W
• Termination Type: SMD
• No. Of Pins: 3
• Hall Effect Type: Switch
• Operating Temperature Range: -40°C To +85°C
• Supply Voltage Min: 3V
• Release Point Min: 5G
• Peak Reflow Compatible (260 C): Yes
• Output Current: 25mA
• Sensor Case Style: SOT23
• Supply Voltage Range: 3V To 24V
• Svhc: No SVHC (15-Dec-2010)
• Rohs Compliant: Yes
• Filter Terminals: SMD
• Bandwidth: 800kHz
• Leaded Process Compatible: Yes
• Operate Point Max: 50G
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: 620-1275-2

A1120, A1121, A1122
Operation
The output of the A1120, A1121, and A1122 devices switches
low (turns on) when a magnetic field perpendicular to the Hall
element exceeds the operate point threshold, B
figure 1). When the magnetic field is reduced below the release
point, B
of the A1125 devices switches high (turns off) when a magnetic
field perpendicular to the Hall element exceeds the operate point
threshold, B
is reduced below the release point, B
low (turns on).
sistor is capable of sinking current up to the short circuit current
limit, I
The difference in the magnetic operate and release points is the
hysteresis, B
clean switching of the output even in the presence of external
mechanical vibration and electrical noise. Powering-on the device
in the hysteresis range (less than B
Figure 1. Device switching behavior. In panels A and B, on the horizontal axis, the B+ direction indicates increasing south polarity magnetic field strength.
This behavior can be exhibited when using an electrical circuit such as that shown in panel C.
and A1125
After turn-on, the output voltage is V
V+
0
0
OM
RP
, which is a minimum of 30 mA.
, the device output goes high (turns off). The output
OP
HYS ,
(see panel B of figure 1). When the magnetic field
B
(A)
HYS
of the device. This built-in hysteresis allows
B+
V
V
Chopper Stabilized Precision Hall Effect Switches
OP
CC
OUT(SAT)
RP
OUT(SAT)
and higher than B
, the device output goes
. The output tran-
OP
V+
0
(see panel A of
0
Functional Description
RP
) will
B
(B)
HYS
give an indeterminate output state. The correct state is attained
after the first excursion beyond B
Applications
It is strongly recommended that an external bypass capacitor be
connected (in close proximity to the Hall element) between the
supply and ground of the device to reduce external noise in the
application. As is shown in panel B of figure 1, a 0.1 μF capacitor
is typical.
Extensive applications information for Hall effect devicers is
available in:
• Hall-Effect IC Applications Guide, Application Note 27701
• Guidelines for Designing Subassemblies Using Hall-Effect
Devices, Application Note 27703.1
• Soldering Methods for Allegro’s Products – SMT and Through-
Hole, Application Note 26009
All are provided in Allegro Electronic Data Book, AMS-702, and
the Allegro Web site, www.allegromicro.com.
B+
V
V
CC
OUT(SAT)
V
S
115 Northeast Cutoff
1.508.853.5000; www.allegromicro.com
Allegro MicroSystems, Inc.
Worcester, Massachusetts 01615-0036 U.S.A.
C
0.1 μF
BYP
OP
or B
A112x
RP
VCC
GND
.
(C)
VOUT
Output
R
L
10