A1120-23,25 Datasheet

Allegro MicroSystems, LLC

View All Related Products | Download PDF Datasheet

Datasheet

DESCRIPTION
The A1120, A1121, A1122, A1123, and A1125 Hall-effect
unipolar switches are extremely temperature-stable and
stress-resistant sensor ICs, especially suited for operation
over extended temperature ranges to 150°C. Superior high-
temperature performance is made possible through dynamic
offset cancellation, which reduces the residual offset voltage
normally caused by device overmolding, temperature
dependencies, and thermal stress.
Each device includes on a single silicon chip a voltage regulator,
Hall-voltage generator, small-signal amplifier, chopper
stabilization, Schmitt trigger, and a short-circuit protected
open-drain output to sink up to 25 mA.
An on-board regulator permits operation with supply voltages
of 3 to 24 V. The advantage of operating down to 3 V is that
the device can be used in 3 V applications or with additional
external resistance in series with the supply pin for greater
protection against high-voltage transient events.
For the A1120, A1121, A1122, and A1123, a south pole of
sufficient strength turns the output on. Removal of the magnetic
field turns the output off. The A1125 is complementary, in that
for these devices, a south pole turns the A1125 output off, and
removal of the magnetic field turns the output on.
Two package styles provide a magnetically optimized package
for most applications. Package type LH is a modified SOT23W,
surface-mount package, while UA is a three-lead ultra-mini
SIP for through-hole mounting. Each package type is lead
(Pb) free (suffix, –T), with a 100% matte-tin-plated leadframe.
A1120-DS, Rev. 18
MCO-0000417
FEATURES AND BENEFITS
▪ AEC-Q100automotivequalified
▪ Unipolarswitchpoints
▪ Resistanttophysicalstress
▪ Superiortemperaturestability
▪ Outputshort-circuitprotection
▪ Operationfromunregulatedsupply
▪ Reverse-batteryprotection
▪ Solid-statereliability
▪ Smallpackagesizes
Chopper-Stabilized Precision Hall-Effect Switches
Functional Block Diagram
A1120, A1121, A1122, A1123, and A1125
February 15, 2019
Regulator
GND
VCC
VOUT
Control
Current Limit
Dynamic Offset
Cancellation
Sample and Hold
To All Subcircuits
Amp
Low-Pass
Filter
PACKAGES:
Not to scale
3-pin SOT23W
(suffix LH)
3-pin SIP,
matrix HD style
(suffix UA)
3-pin SIP,
chopper style
(suffix UA)
NOT FOR
NEW DESIGN
Chopper-Stabilized Precision Hall-Effect Switches
A1120, A1121, A1122,
A1123, and A1125
2
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
SELECTION GUIDE
Part Number Packing [1] Mounting Ambient, TA
(°C)
Switchpoints
(Typ.) (G) Output In South (Positive)
Magnetic Field
BOP BRP
A1120ELHLX-T 13-in. reel, 10000 pieces/reel 3-pin SOT23W surface mount
–40 to 85
35 25
On (logic low)
A1120ELHLT-T
[2] 7-in. reel, 3000 pieces/reel 3-pin SOT23W surface mount
A1120EUA-T
[3] Bulk, 500 pieces/bag 3-pin SIP through hole
A1120LLHLX-T 13-in. reel, 10000 pieces/reel 3-pin SOT23W surface mount
–40 to 150
A1120LLHLT-T
[2] 7-in. reel, 3000 pieces/reel 3-pin SOT23W surface mount
A1120LUA-T
[3] Bulk, 500 pieces/bag 3-pin SIP through hole
A1121ELHLX-T 13-in. reel, 10000 pieces/reel 3-pin SOT23W surface mount
–40 to 85
95 70
A1121ELHLT-T
[2] 7-in. reel, 3000 pieces/reel 3-pin SOT23W surface mount
A1121EUA-T
[3] Bulk, 500 pieces/bag 3-pin SIP through hole
A1121LLHLX-T 13-in. reel, 10000 pieces/reel 3-pin SOT23W surface mount
–40 to 150
A1121LLHLT-T
[2] 7-in. reel, 3000 pieces/reel 3-pin SOT23W surface mount
A1121LUA-T
[3] Bulk, 500 pieces/bag 3-pin SIP through hole
A1122ELHLX-T 13-in. reel, 10000 pieces/reel 3-pin SOT23W surface mount
–40 to 85
150 125
A1122ELHLT-T
[2] 7-in. reel, 3000 pieces/reel 3-pin SOT23W surface mount
A1122EUA-T
[3] Bulk, 500 pieces/bag 3-pin SIP through hole
A1122LLHLX-T 13-in. reel, 10000 pieces/reel 3-pin SOT23W surface mount
–40 to 150
A1122LLHLT-T
[2] 7-in. reel, 3000 pieces/reel 3-pin SOT23W surface mount
A1122LUA-T
[3] Bulk, 500 pieces/bag 3-pin SIP through hole
A1123LLHLX-T 13-in. reel, 10000 pieces/reel 3-pin SOT23W surface mount
–40 to 150 280 225
A1123LLHLT-T
[2] 7-in. reel, 3000 pieces/reel 3-pin SOT23W surface mount
A1123LUA-T
[3] Bulk, 500 pieces/bag 3-pin SIP through hole
A1125ELHLX-T 13-in. reel, 10000 pieces/reel 3-pin SOT23W surface mount
–40 to 85
35 25 Off (logic high)
A1125ELHLT-T
[2] 7-in. reel, 3000 pieces/reel 3-pin SOT23W surface mount
A1125EUA-T
[3] Bulk, 500 pieces/bag 3-pin SIP through hole
A1125LLHLX-T 13-in. reel, 10000 pieces/reel 3-pin SOT23W surface mount
–40 to 150
A1125LLHLT-T
[2] 7-in. reel, 3000 pieces/reel 3-pin SOT23W surface mount
A1125LUA-T
[3] Bulk, 500 pieces/bag 3-pin SIP through hole
[1] Contact Allegro for additional packing options.
[2] Available through authorized Allegro distributors only.
[3] The chopper-style UA package is not for new design; the matrix HD style UA package is recommended for new designs.
Chopper-Stabilized Precision Hall-Effect Switches
A1120, A1121, A1122,
A1123, and A1125
3
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
ABSOLUTE MAXIMUM RATINGS
Characteristic Symbol Notes Rating Units
Forward Supply Voltage VCC 26.5 V
Reverse Supply Voltage VRCC –30 V
Output Off Voltage VOUT 26 V
Continuous Output Current IOUT 25 mA
Reverse Output Current IROUT –50 mA
Operating Ambient Temperature TA
Range E –40 to 85 °C
Range L –40 to 150 °C
Maximum Junction Temperature TJ(max) 165 °C
Storage Temperature Tstg –65 to 170 °C
PINOUT DIAGRAMS AND TERMINAL LIST TABLE
Terminal List
Name Description Number
Package LH Package UA
VCC Connects power supply to chip 1 1
VOUT Output from circuit 2 3
GND Ground 3 2
1
3
2
GND
VOUT
VCC
Package UAPackage LH
1
2
3
GND
VOUT
VCC
Chopper-Stabilized Precision Hall-Effect Switches
A1120, A1121, A1122,
A1123, and A1125
4
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
ELECTRICAL CHARACTERISTICS: Valid over full operating voltage and ambient temperature ranges, unless otherwise noted
Characteristics Symbol Test Conditions Min. Typ. [1] Max. Unit [2]
ELECTRICAL CHARACTERISTICS
Forward Supply Voltage VCC Operating, TJ < 165°C 3 24 V
Output Leakage Current IOUTOFF
A1120
A1121
A1122
A1123
VOUT = 24 V, B < BRP – 10 µA
A1125 VOUT = 24 V, B > BOP – 10 µA
Output Saturation Voltage VOUT(SAT)
A1120
A1121
A1122
A1123
IOUT = 20 mA, B > BOP 185 500 mV
A1125 IOUT = 20 mA, B < BRP 185 500 mV
Output Current Limit IOM
A1120
A1121
A1122
A1123
B > BOP 30 – 60 mA
A1125 B < BRP 30 – 60 mA
Power-On Time [3] tPO
VCC > 3.0 V, B < BRP(min) – 10 G,
B > BOP(max) + 10 G – 25 µs
Chopping Frequency fC– 800 – kHz
Output Rise Time [3][4] trRL = 820 Ω, CS = 20 pF 0.2 2 µs
Output Fall Time [3][4] tfRL = 820 Ω, CS = 20 pF 0.1 2 µs
Supply Current
ICC(ON)
A1120
A1121
A1122
A1123
VCC = 12 V, B > BOP 4 mA
A1125 VCC = 12 V, B < BRP – 4 mA
ICC(OFF)
A1120
A1121
A1122
A1123
VCC = 12 V, B < BRP – 4 mA
A1125 VCC = 12 V, B > BOP – 4 mA
Reverse Supply Current IRCC VRCC = –30 V –5 mA
Supply Zener Clamp Voltage VZICC = 5 mA; TA = 25°C 28 V
Zener Impedance IZICC = 5 mA; TA = 25°C 50 Ω
Continued on the next page…
Chopper-Stabilized Precision Hall-Effect Switches
A1120, A1121, A1122,
A1123, and A1125
5
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
ELECTRICAL CHARACTERISTICS (continued): Valid over full operating voltage and ambient temperature ranges,
unless otherwise noted
Characteristics Symbol Test Conditions Min. Typ. [1] Max. Unit [2]
MAGNETIC CHARACTERISTICS
Operate Point BOP
A1120 35 50 G
A1121 50 95 135 G
A1122 120 150 200 G
A1123 205 280 355 G
A1125 35 50 G
Release Point BRP
A1120 5 25 – G
A1121 40 70 110 G
A1122 110 125 190 G
A1123 150 225 300 G
A1125 5 25 – G
Hysteresis BHYS
A1120
(BOP – BRP)
– 10 – G
A1121 10 25 42 G
A1122 10 25 42 G
A1123 30 55 80 G
A1125 – 10 – G
[1] Typical data are are at TA = 25°C and VCC = 12 V, and are for initial design estimations only.
[2] 1 G (gauss) = 0.1 mT (millitesla).
[3] Guaranteed by device design and characterization.
[4] CS = oscilloscope probe capacitance.
Chopper-Stabilized Precision Hall-Effect Switches
A1120, A1121, A1122,
A1123, and A1125
6
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
THERMAL CHARACTERISTICS: May require derating at maximum conditions; see application information
Characteristic Symbol Test Conditions Value Units
Package Thermal Resistance RθJA
Package LH, 1-layer PCB with copper limited to solder pads 228 °C/W
Package LH, 2-layer PCB with 0.463 in.
2 of copper area each side
connected by thermal vias 110 °C/W
Package UA, 1-layer PCB with copper limited to solder pads 165 °C/W
6
7
8
9
2
3
4
5
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
20 40 60 80 100 120 140 160 180
Temperature (ºC)
Maximum Allowable V
CC
(V)
T
J(max)
= 165ºC; I
CC
= I
CC(max)
Power Derating Curve
(R
θJA
= 228 ºC/W)
Package LH, 1-layer PCB
(R
θJA
= 110 ºC/W)
Package LH, 2-layer PCB
(R
θJA
= 165 ºC/W)
Package UA, 1-layer PCB
V
CC(min)
V
CC(max)
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
20 40 60 80 100 120 140 160 180
Temperature (°C)
Power Dissipation, PD (mW)
Power Dissipation versus Ambient Temperature
(R
θJA
= 165 ºC/W)
Package UA, 1-layer PCB
(R
θJA
= 228 ºC/W)
Package LH, 1-layer PCB
(R
θJA
= 110 ºC/W)
Package LH, 2-layer PCB
Chopper-Stabilized Precision Hall-Effect Switches
A1120, A1121, A1122,
A1123, and A1125
7
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
CHARACTERISTIC PERFORMANCE
A1120, A1121, A1122, A1123, and A1125 Electrical Characteristics
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
2 6 10 14 18 22 26
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
- 60 - 40 - 20 0 20 40 60 80 100 120 140 160
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
- 60 - 40 - 20 0 20 40 60 80 100 120 140 160
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
2 6 10 14 18 22 26
0
50
100
150
200
250
300
- - - 0 20 40 60 80 100 120 140 160
0
50
100
150
200
250
300
2 6 10 14 18 22 26
60 40 20
Average Supply Current (On) versus Average Supply VoltageAverage Supply Current (On) versus Ambient Temperature
Average Supply Current (Off) versus Average Supply VoltageAverage Supply Current (Off) versus Ambient Temperature
Average Output Saturation Voltage versus Supply Voltage
Average Output Saturation Voltage versus Ambient Temperature
TA (°C)
ICC(av) (mA)
ICC(av) (mA)
ICC(av) (mA)
ICC(av) (mA)
VOUT(sat) (V)
VOUT(sat) (V)
VCC (V)
TA (°C) VCC (V)
TA (°C) VCC (V)
TA (°C)
–40
25
150
VCC (V)
3.0
12
24
VCC (V)
3.0
3.8
4.2
12
24
A112x*
*A1120, A1121,
A1122, and A1125
A1123
VCC (V)
3.0
12
24
A112x*
*A1120, A1121,
A1122, and A1125
A1123
A112x*
*A1120, A1121,
A1122, and A1125
A1123
TA (°C)
–40
25
150
A112x*
*A1120, A1121,
A1122, and A1125
A1123
TA (°C)
–40
25
150
A112x*
*A1120, A1121,
A1122, and A1125
A1123
A112x*
*A1120, A1121,
A1122, and A1125
A1123
Chopper-Stabilized Precision Hall-Effect Switches
A1120, A1121, A1122,
A1123, and A1125
8
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
A1120 and A1125 Magnetic Characteristics
0
5
10
15
20
25
30
35
40
45
50
-60 -40 -20 0 20 40 60 80 100 120 140 160
0
5
10
15
20
25
30
35
40
45
50
-60 -40 -20 0 20 40 60 80 100 120 140 160
0
2
4
6
8
10
12
14
16
18
20
-60 -40 -20 0 20 40 60 80 100 120 140 160
0
5
10
15
20
25
30
35
40
45
50
2 6 10 14 18 22 26
0
5
10
15
20
25
30
35
40
45
50
2 6 10 14 18 22 26
0
2
4
6
8
10
12
14
16
18
20
2 6 10 14 18 22 26
Average Operate Point versus Average Supply VoltageAverage Operate Point versus Ambient Temperature
Average Release Point versus Average Supply VoltageAverage Release Point versus Ambient Temperature
Average Switchpoint Hysteresis versus Supply Voltage
Average Switchpoint Hysteresis versus Ambient Temperature
TA (°C)
BOP (G)
BOP (G)
BRP (G)
BRP (G)
BHYS (G)
BHYS (G)
VCC (V)
TA (°C) VCC (V)
TA (°C) V
CC
(V)
VCC (V)
3.0
24
VCC (V)
3.0
24
VCC (V)
3.0
24
TA (°C)
–40
25
150
TA (°C)
–40
25
150
TA (°C)
–40
25
150
Chopper-Stabilized Precision Hall-Effect Switches
A1120, A1121, A1122,
A1123, and A1125
9
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
A1121 Magnetic Characteristics
- 60 - 40 - 20 0 20 40 60 80 100 120 140 160 2 6 10 14 18 22 26
26
- 60 - 40 - 20 0 20 40 60 80 100 120 140 160 2 6 10 14 18 22
- 60 - 40 - 20 0 20 40 60 80 100 120 140 160 2 6 10 14 18 22 26
40
50
60
70
80
90
100
110
10
15
20
25
30
35
40
50
60
70
80
90
100
110
120
130
140
50
60
70
80
90
100
110
120
130
140
40
50
60
70
80
90
100
110
10
15
20
25
30
35
40
Average Operate Point versus Average Supply VoltageAverage Operate Point versus Ambient Temperature
Average Release Point versus Average Supply VoltageAverage Release Point versus Ambient Temperature
Average Switchpoint Hysteresis versus Supply Voltage
Average Switchpoint Hysteresis versus Ambient Temperature
TA (°C)
B
OP
(G)
BOP (G)
B
RP
(G)
BRP (G)
B
HYS
(G)
BHYS (G)
VCC (V)
TA (°C) VCC (V)
TA (°C) VCC (V)
VCC (V)
3.0
12
24
VCC (V)
3.0
12
24
VCC (V)
3.0
12
24
TA (°C)
–40
25
150
TA (°C)
–40
25
150
TA (°C)
–40
25
150
Chopper-Stabilized Precision Hall-Effect Switches
A1120, A1121, A1122,
A1123, and A1125
10
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
A1122 Magnetic Characteristics
- 60 - 40 - 20 0 20 40 60 80 100 120 140 160 2 6 10 14 18 22 26
26
- 60 - 40 - 20 0 20 40 60 80 100 120 140 160 2 6 10 14 18 22
- 60 - 40 - 20 0 20 40 60 80 100 120 140 160 2 6 10 14 18 22 26
10
15
20
25
30
35
40
200
190
180
170
160
150
140
130
120
200
190
180
170
160
150
140
130
120
190
180
170
160
150
140
130
120
110
190
180
170
160
150
140
130
120
110
10
15
20
25
30
35
40
Average Operate Point versus Average Supply VoltageAverage Operate Point versus Ambient Temperature
Average Release Point versus Average Supply VoltageAverage Release Point versus Ambient Temperature
Average Switchpoint Hysteresis versus Supply Voltage
Average Switchpoint Hysteresis versus Ambient Temperature
TA (°C)
B
OP
(G)
BOP (G)
B
RP
(G)
BRP (G)
B
HYS
(G)
BHYS (G)
VCC (V)
TA (°C) VCC (V)
TA (°C) VCC (V)
VCC (V)
3.0
12
24
VCC (V)
3.0
12
24
VCC (V)
3.0
12
24
TA (°C)
–40
25
150
TA (°C)
–40
25
150
TA (°C)
–40
25
150
Chopper-Stabilized Precision Hall-Effect Switches
A1120, A1121, A1122,
A1123, and A1125
11
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
A1123 Magnetic Characteristics
355
350
305
280
255
230
205
355
350
305
280
255
230
205
-60 -40 -20 0 20 40 60 80 100 120 140 160
-60 -40 -20 0 20 40 60 80 100 120 140 160
-60 -40 -20 0 20 40 60 80 100 120 140 160
2 6 10 14 18 22 26
2 6 10 14 18 22 26
2 6 10 14 18 22 26
300
275
250
225
200
175
150
300
275
250
225
200
175
150
80
75
70
65
60
55
50
45
40
35
30
80
75
70
65
60
55
50
45
40
35
30
Average Operate Point versus Average Supply VoltageAverage Operate Point versus Ambient Temperature
Average Release Point versus Average Supply VoltageAverage Release Point versus Ambient Temperature
Average Switchpoint Hysteresis versus Supply Voltage
Average Switchpoint Hysteresis versus Ambient Temperature
TA (°C)
BOP (G)
BOP (G)
BRP (G)
BRP (G)
BHYS (G)
BHYS (G)
VCC (V)
TA (°C) VCC (V)
TA (°C) V
CC
(V)
TA (°C)
–40
25
150
TA (°C)
–40
25
150
TA (°C)
–40
25
150
TA (°C)
3
12
24
TA (°C)
3
12
24
TA (°C)
3
12
24
Chopper-Stabilized Precision Hall-Effect Switches
A1120, A1121, A1122,
A1123, and A1125
12
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
CBYP
A112x
VOUT
GND
0.1 µF
VCC
Output
RL
VS
Operation
The output of the A1120, A1121, A1122, and A1123 devices
switches low (turns on) when a magnetic field perpendicular to
the Hall element exceeds the operate point threshold, BOP (see
panel A of figure 1). When the magnetic field is reduced below
the release point, BRP , the device output goes high (turns off).
The output of the A1125 devices switches high (turns off) when
a magnetic field perpendicular to the Hall element exceeds the
operate point threshold, BOP (see panel B of figure 1). When the
magnetic field is reduced below the release point, BRP , the device
output goes low (turns on).
After turn-on, the output voltage is VOUT(SAT)
. The output tran-
sistor is capable of sinking current up to the short circuit current
limit, IOM, which is a minimum of 30 mA.
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 range (less than BOP and higher than BRP) will
give 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 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 devices 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 on the Allegro website, www.allegromicro.com.
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.
(A) (B) (C)
FUNCTIONAL DESCRIPTION
BOP
BRP
BHYS
VCC
VOUT
VOUT(SAT)
Switch to Low
Switch to High
B+
V+
0
0
BOP
BRP
BHYS
VCC
VOUT
VOUT(SAT)
Switch to Low
Switch to High
B+
V+
0
0
Chopper-Stabilized Precision Hall-Effect Switches
A1120, A1121, A1122,
A1123, and A1125
13
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Amp
Regulator
Clock/Logic
Hall Element
Sample and
Hold
Low-Pass
Filter
Chopper Stabilization Technique
When using Hall effect technology, a limiting factor for
switchpoint accuracy is the small signal voltage developed across
the Hall element. This voltage is disproportionally small relative
to the offset that can be produced at the output of the Hall ele-
ment. This makes it difficult to process the signal while main-
taining an accurate, reliable output over the specified operating
temperature and voltage ranges.
Chopperstabilizationisauniqueapproachusedtominimize
Halloffsetonthechip.TheAllegrotechnique,namelyDynamic
QuadratureOffsetCancellation,removeskeysourcesoftheout-
put drift induced by thermal and mechanical stresses. This offset
reductiontechniqueisbasedonasignalmodulation-demodula-
tion process. The undesired offset signal is separated from the
magneticfield-inducedsignalinthefrequencydomain,through
modulation.Thesubsequentdemodulationactsasamodulation
process for the offset, causing the magnetic field induced signal
to recover its original spectrum at baseband, while the dc offset
becomesahigh-frequencysignal.Themagneticsourcedsignal
thencanpassthroughalow-passfilter,whilethemodulatedDC
offset is suppressed. This configuration is illustrated in figure 2.
Thechopperstabilizationtechniqueusesa400kHzhighfre-
quencyclock.Fordemodulationprocess,asampleandhold
techniqueisused,wherethesamplingisperformedattwicethe
chopperfrequency(800kHz).Thishigh-frequencyoperation
allows a greater sampling rate, which results in higher accuracy
and faster signal-processing capability. This approach desensi-
tizes the chip to the effects of thermal and mechanical stresses,
andproducesdevicesthathaveextremelystablequiescentHall
output voltages and precise recoverability after temperature
cycling.Thistechniqueismadepossiblethroughtheuseofa
BiCMOS process, which allows the use of low-offset, low-noise
amplifiers in combination with high-density logic integration and
sample-and-hold circuits.
The repeatability of magnetic field-induced switching is affected
slightlybyachoppertechnique.However,theAllegrohigh
frequencychoppingapproachminimizestheaffectofjitterand
makes it imperceptible in most applications. Applications that are
morelikelytobesensitivetosuchdegradationarethoserequiring
precise sensing of alternating magnetic fields; for example, speed
sensing of ring-magnet targets. For such applications, Allegro
recommends its digital device families with lower sensitivity
tojitter.Formoreinformationonthosedevices,contactyour
Allegro sales representative.
Figure 2. Model of chopper stabilization technique
Chopper-Stabilized Precision Hall-Effect Switches
A1120, A1121, A1122,
A1123, and A1125
14
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
Power Derating
Thedevicemustbeoperatedbelowthemaximumjunction
temperature of the device, TJ(max). Under certain combinations of
peakconditions,reliableoperationmayrequirederatingsupplied
power or improving the heat dissipation properties of the appli-
cation. This section presents a procedure for correlating factors
affecting operating TJ. (Thermal data is also available on the
Allegro MicroSystems website.)
The Package Thermal Resistance, RθJA, is a figure of merit sum-
marizing the ability of the application and the device to dissipate
heatfromthejunction(die),throughallpathstotheambientair.
Its primary component is the Effective Thermal Conductivity, K,
oftheprintedcircuitboard,includingadjacentdevicesandtraces.
Radiation from the die through the device case, RθJC, is relatively
small component of RθJA. Ambient air temperature, TA, and air
motion are significant external factors, damped by overmolding.
Theeffectofvaryingpowerlevels(PowerDissipation,PD), can
be estimated. The following formulas represent the fundamental
relationships used to estimate TJ, at PD.
PD= VIN × IIN (1)
 ΔT = PD × RθJA (2)
TJ = TA + ΔT (3)
For example, given common conditions such as: TA= 25°C,
VCC = 12 V, ICC = 1.6 mA, and RθJA = 165°C/W, then:
PD= VCC × ICC = 12 V × 1.6 mA = 19 mW
ΔT = PD × RθJA = 19 mW × 165°C/W = 3°C
TJ = TA + ΔT=25°C+3°C=28°C
A worst-case estimate, PD(max), represents the maximum allow-
able power level (VCC(max), ICC(max)), without exceeding TJ(max),
at a selected RθJA and TA.
Example: Reliability for VCC at TA
=
150°C, package LH, using a
minimum-K PCB.
Observe the worst-case ratings for the device, specifically:
RθJA=
228°C/W,TJ(max) =
165°C, VCC(max)
= 24 V, and
ICC(max) = 4 mA.
Calculate the maximum allowable power level, PD(max). First,
invertequation3:
ΔTmax = TJ(max) – TA = 165
°C
150
°C = 15
°C
This provides the allowable increase to TJ resulting from internal
powerdissipation.Then,invertequation2:
PD(max) = ΔTmax ÷ RθJA=15°C÷228°C/W=66mW
Finally,invertequation1withrespecttovoltage:
 VCC(est) = PD(max) ÷ ICC(max) = 66 mW ÷ 4 mA = 16.5 V
The result indicates that, at TA, the application and device can
dissipateadequateamountsofheatatvoltages≤VCC(est).
Compare VCC(est) to VCC(max). If VCC(est)≤VCC(max), then reli-
able operation between VCC(est) and VCC(max)requiresenhanced
RθJA. If VCC(est)≥VCC(max), then operation between VCC(est)
and VCC(max) is reliable under these conditions.
Chopper-Stabilized Precision Hall-Effect Switches
A1120, A1121, A1122,
A1123, and A1125
15
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
0.55 REF
Gauge Plane
Seating Plane
0.25 BSC
0.95 BSC
0.95
1.00
0.70
2.40
2
1
AActive Area Depth, 0.28 mm REF
B
C
B
Reference land pattern layout
All pads a minimum of 0.20 mm from all adjacent pads; adjust as necessary
to meet application process requirements and PCB layout tolerances
Branding scale and appearance at supplier discretion
A
PCB Layout Reference View
Branded Face
CStandard Branding Reference View
N = Last two digits of device part number
T = Temperature code (letter)
1
NNT
N = Last three digits of device part number
1
NNN
2.90 +0.10
–0.20
4°±4°
8X 10° REF
0.180+0.020
–0.053
0.05 +0.10
–0.05
0.25 MIN
1.91 +0.19
–0.06
2.98 +0.12
–0.08
1.00 ±0.13
0.40 ±0.10
For Reference Only; not for tooling use (reference dwg. 802840)
Dimensions in millimeters
Dimensions exclusive of mold flash, gate burrs, and dambar protrusions
Exact case and lead configuration at supplier discretion within limits shown
DHall element, not to scale
D
D
D
1.49
0.96
3
Package LH, 3-Pin (SOT-23W)
Chopper-Stabilized Precision Hall-Effect Switches
A1120, A1121, A1122,
A1123, and A1125
16
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
(Reference DWG-0000404, Rev. 1)
Dimensions in millimeters – NOT TO SCALE
Dimensions exclusive of mold flash, gate burrs, and dambar protrusions
Exact case and lead configuration at supplier discretion within limits shown
231
1.27 NOM
1.02 MAX 0.51 MAX
0.79 REF
B
A
B
C
A
D
E
D
E
E
2.04
1.44 E
Branding scale and appearance at supplier discretio
Hall element, not to scale
Mold Ejector
Pin Indent
Branded
Face
4.09+0.08
–0.05
0.41 +0.03
–0.06
3.02+0.08
–0.05
0.43+0.05
–0.07
5
Dambar removal protrusion (6×)
Gate and tie bar burr area
Active Area Depth, 0.50 ±0.08 mm
Standard Branding Reference View
2 × 45°
C
45°
3 × 10°
1.52 ±0.05
NNT
= Supplier emblem
= Last two digits of device part numberN
1
= Temperature codeT
Package UA, 3-Pin SIP, Matrix Style
Chopper-Stabilized Precision Hall-Effect Switches
A1120, A1121, A1122,
A1123, and A1125
17
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
2 31
0.79 REF
1.27 NOM
2.16
MAX
0.51
REF
45°
C
45°
B
E
E
E
2.04
1.44
Gate burr area
A
B
C
Dambar removal protrusion (6X)
A
D
E
D
Branding scale and appearance at supplier discretion
Hall element, not to scale
Active Area Depth, 0.50 mm REF
For Reference Only; not for tooling use (reference DWG-9049)
Dimensions in millimeters
Dimensions exclusive of mold flash, gate burrs, and dambar protrusions
Exact case and lead configuration at supplier discretion within limits shown
Standard Branding Reference View
= Supplier emblem
N = Last two digits of device part number
T = Temperature code
NNT
1
Mold Ejector
Pin Indent
Branded
Face
4.09 +0.08
–0.05
0.41 +0.03
–0.06
3.02 +0.08
–0.05
0.43 +0.05
–0.07
15.75 ±0.51
1.52 ±0.05
Package UA, 3-Pin SIP, Chopper Style
NOT FOR
NEW DESIGN
Chopper-Stabilized Precision Hall-Effect Switches
A1120, A1121, A1122,
A1123, and A1125
18
Allegro MicroSystems, LLC
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
For the latest version of this document, visit our website:
www.allegromicro.com
Revision History
Number Date Description
15 September 3, 2013 Update product offerings;
Update UA package drawing
16 September 16, 2015 Added AEC-Q100 qualification under Features and Benefits
17 November 4, 2016 Chopper-style UA package designated as not for new design
18 February 15, 2019 Minor editorial updates
Copyright ©2019, Allegro MicroSystems, LLC
Allegro MicroSystems, LLC reserves the right to make, from time to time, such departures from the detail specifications as may be required to
permit improvements in the performance, reliability, or manufacturability of its products. Before placing an order, the user is cautioned to verify that
the information being relied upon is current.
Allegro’s products are not to be used in any devices or systems, including but not limited to life support devices or systems, in which a failure of
Allegro’s product can reasonably be expected to cause bodily harm.
The information included herein is believed to be accurate and reliable. However, Allegro MicroSystems, LLC assumes no responsibility for its
use; nor for any infringement of patents or other rights of third parties which may result from its use.
Copies of this document are considered uncontrolled documents.

Products

MAGNETIC SWITCH UNIPOLAR SOT23W
入手可能な数量2650
単価186
MAGNETIC SWITCH UNIPOLAR SOT23W
入手可能な数量0
単価166
MAGNETIC SWITCH UNIPOLAR SOT23W
入手可能な数量0
単価196
MAGNETIC SWITCH UNIPOLAR SOT23W
入手可能な数量0
単価196
MAGNETIC SWITCH UNIPOLAR SOT23W
入手可能な数量0
単価216
MAGNETIC SWITCH UNIPOLAR SOT23W
入手可能な数量0
単価216
MAGNETIC SWITCH UNIPOLAR 3SIP
入手可能な数量0
単価196
MAGNETIC SWITCH UNIPOLAR 3SIP
入手可能な数量0
単価216
MAGNETIC SWITCH UNIPOLAR SOT23W
入手可能な数量0
単価54.41693
MAGNETIC SWITCH UNIPOLAR SOT23W
入手可能な数量0
単価57.2438
MAGNETIC SWITCH UNIPOLAR 3SIP
入手可能な数量0
単価58.74563
MAGNETIC SWITCH UNIPOLAR SOT23W
入手可能な数量0
単価61.8375
MAGNETIC SWITCH UNIPOLAR 3SIP
入手可能な数量0
単価62.1025
MAGNETIC SWITCH UNIPOLAR 3SIP
入手可能な数量0
単価63.78088
MAGNETIC SWITCH UNIPOLAR SOT23W
入手可能な数量0
単価66.78443
MAGNETIC SWITCH UNIPOLAR SOT23W
入手可能な数量0
単価67.13783
MAGNETIC SWITCH UNIPOLAR SOT23W
入手可能な数量0
単価68.37453
MAGNETIC SWITCH UNIPOLAR 3SIP
入手可能な数量0
単価70.49463
MAGNETIC SWITCH UNIPOLAR 3SIP
入手可能な数量0
単価73.85163
MAGNETIC SWITCH UNIPOLAR 3SIP
入手可能な数量0
単価73.85163