A3280, A3281, and A3283
Chopper-Stabilized, Precision Hall-Effect Latches
Last Time Buy
The A3283 part is in production but has been determined to be
LAST TIME BUY. This classification indicates that the product is
obsolete and notice has been given. Sale of this device is currently
restricted to existing customer applications. The device should not be
purchased for new design applications because of obsolescence in the
near future. Samples are no longer available.
Date of status change: August 16, 2010
Deadline for receipt of LAST TIME BUY orders: October 29, 2010
Recommended Substitutions:
For existing customer transition, and for new customers or new appli-
cations, refer to the
A1223.
Note: The A3280 and A3281 are obsolete. For existing customer transi-
tion, and for new customers or new applications, refer to the
A1222.
NOTE: For detailed information on purchasing options, contact your
local Allegro field applications engineer or sales representative.
Allegro MicroSystems, Inc. reserves the right to make, from time to time, revisions to the anticipated product life cycle plan
for a product to accommodate changes in production capabilities, alternative product availabilities, or market demand. The
information included herein is believed to be accurate and reliable. However, Allegro MicroSystems, Inc. assumes no respon-
sibility for its use; nor for any infringements of patents or other rights of third parties which may result from its use.
A3280, A3281, and A3283
Chopper-Stabilized, Precision
Hall-Effect Latches
Features and Benefits
▪
Symmetrical switch points
▪
Resistant to physical stress
▪
Superior temperature stability
▪
Output short-circuit protection
▪
Operation from unregulated supply
▪
Reverse battery protection
▪
Solid-state reliability
▪
Small size
Description
The A3280, A3281, and A3283 Hall-effect latches
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. The three devices are
identical except for magnetic switch points.
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-collector output to sink up to 25 mA.
A south pole of sufficient strength will turn the output
on. A north pole is necessary to turn the output off. An
on-board regulator permits operation with supply voltages
of 4.2 to 24 volts.
Three package styles provide a magnetically optimized
package for most applications. Package type LH is a
modified SOT23W surface-mount package, LT is a
miniature SOT89/TO-243AA transistor package for
surface-mount applications; while UA is a three-lead
ultra-mini-SIP for through-hole mounting. Each package
type is lead (Pb) free (suffix,
–T),
with 100% matte tin
leadframe plating.
Packages:
Package LH
Package LT
Package UA
Not to scale
Functional Block Diagram
27609.20-DS, Rev. M
A3280, A3281
and
A3283
Chopper-Stabilized, Precision
Hall-Effect Latches
Selection Guide
Part Number
A3283ELTTR-T
A3283EUA-T
A3283LLHLT-T
A3283LLTTR-T
A3283LUA-T
Packing*
7-in. reel, 1000 pieces/reel
Bulk, 500 pieces/bag
7-in. reel, 3000 pieces/reel
7-in. reel, 1000 pieces/reel
Bulk, 500 pieces/bag
Mounting
SOT89 Surface Mount
3-pin SIP through hole
SOT23W Surface Mount
SOT89 Surface Mount
3-pin SIP through hole
–40 to 150
Ambient, T
A
(°C)
–40 to 85
–180
180
B
RP(MIN)
(T
A
= 25°C)
(G)
B
OP(MAX)
(T
A
= 25°C)
(G)
*Contact Allegro for additional packing options.
Absolute Maximum Ratings
Characteristic
Supply Voltage
Reverse Battery Voltage
Magnetic Flux Density
Output Off Voltage
Continuous Output Current
Reverse Output Currrent
Operating Ambient Temperature
Maximum Junction Temperature
Storage Temperature
Symbol
V
CC
V
RCC
B
V
OUT
I
OUT
I
ROUT
T
A
T
J
(max)
T
stg
Range E
Range L
Notes
Rating
26.5
–30
Unlimited
26
Units
V
V
G
V
mA
mA
ºC
ºC
ºC
ºC
Internal current limiting is intended to protect
the device from output short circuits.
25
–50
–40 to 85
–40 to 150
165
–65 to 170
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
2
A3280, A3281
and
A3283
Chopper-Stabilized, Precision
Hall-Effect Latches
X
PTCT
V
CC
1
2
3
GROUND
SUPPLY
Dwg. PH-003-2
Suffix '–LT' & '–UA' Pinning
(SOT89/TO-243AA & ultra-mini SIP)
OUTPUT
Suffix ‘–LH’ Pinning
(SOT23W)
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
3
A3280, A3281
and
A3283
Chopper-Stabilized, Precision
Hall-Effect Latches
ELECTRICAL CHARACTERISTICS over operating temperature range.
Limits
Characteristic
Supply Voltage Range
Output Leakage Current
Output Saturation Voltage
Output Current Limit
Power-On Time
Chopping Frequency
Output Rise Time
Output Fall Time
Supply Current
Symbol
V
CC
I
OFF
V
OUT(SAT)
I
OM
t
po
f
C
t
r
t
f
I
CC
R
L
= 820
,
C
L
= 20 pF
R
L
= 820
,
C
L
= 20 pF
B < B
RP
, V
CC
= 12 V
B > B
OP
, V
CC
= 12 V
Reverse Battery Current
Zener Voltage
Zener Impedance
NOTES:
I
CC
V
Z
+ V
D
z
z
+ z
D
V
RCC
= -30 V
I
CC
= 15 mA, T
A
= 25°C
I
CC
= 15 mA, T
A
= 25°C
Test Conditions
Operating, T
J
< 170°C
1
V
OUT
= 24 V, B < B
RP
I
OUT
= 20 mA, B > B
OP
B > B
OP
V
CC
> 4.2 V
Min.
4.2
–
–
30
–
–
–
–
–
–
–
28
–
Typ.
–
–
185
–
–
340
0.2
0.1
3.0
4.0
–
32
50
Max.
24
10
500
60
50
–
2.0
2.0
8.0
8.0
-5.0
37
–
Units
V
μA
mV
mA
μs
kHz
μs
μs
mA
mA
mA
V
1. Maximum voltage must be adjusted for power dissipation and junction temperature.
2. B
OP
= operate point (output turns on); B
RP
= release point (output turns off).
3. Typical Data is at T
A
= +25°C and V
CC
= 12 V and is for design information only.
MAGNETIC CHARACTERISTICS over operating voltage range.
Part Numbers
1
A3280
Characteristic
Operate Point, B
OP
Test Conditions
at T
A
= +25°C and T
A
= max.
at T
A
= -40°C
Release Point, B
RP
at T
A
= +25°C and T
A
= max.
at T
A
= -40°C
Hysteresis, B
hys
at T
A
= +25°C and T
A
= max.
at T
A
= -40°C
Min.
5.0
5.0
-40
-40
10
–
Typ.
22
–
-23
–
45
–
Max.
40
40
-5.0
-5.0
80
80
Min.
15
15
-90
-90
30
–
A3281
Typ.
50
–
-50
–
100
–
Max.
90
90
-15
-15
180
180
Min.
100
100
-180
-200
–
–
A3283
Typ.
150
–
-150
–
300
–
Max.
180
200
-100
-100
360
360
Units
G
G
G
G
G
G
(B
OP
- B
RP
)
NOTES:
1. Complete part number includes a suffix to identify operating temperature range (E or L) and package type (LH, LT, or UA).
2. As used here, negative
fl
ux densities are defined as less than zero (algebraic convention) and -50 G is less than +10 G.
3. Typical Data is at TA = +25°C and VCC = 12 V and is for design information only.
4. 1 gauss (G) is exactly equal to 0.1 millitesla (mT).
Allegro MicroSystems, Inc.
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com
4