3421
AND
3422
PRELIMINARY INFORMATION
(subject to change without notice)
September 6, 2000
HALL-EFFECT,
DIRECTION-DETECTION SENSORS
The A3421xKA and A3422xKA Hall-effect, direction-detection
sensors are a new generation of special-function integrated sensors that
are capable of sensing the direction of rotation of a ring magnet. These
transducers provide separate digital outputs that provide information on
magnet rotation speed, direction, and magnet pole count. These devices
eliminate the major manufacturing hurdles encountered in fine-pitch
direction-detection applications, namely maintaining accurate mechani-
cal location between the two active Hall elements. Here, the two Hall
elements are photolithographically aligned to better than 1
µm,
as
contrasted with 100
µm
or worse mechanical location tolerance when
manufactured discretely. These highly sensitive, temperature-stable,
magnetic transducers are ideal for use in digital-encoder systems in the
harsh environments of automotive or industrial applications. The
A3421xKA is a high-hysteresis device designed for low-resolution
pulse counting while the A3422xKA is a high-sensitivity device
optimized for use with high-density magnets.
The A3421xKA and A3422xKA monolithic integrated circuits
contain two independent Hall-effect latches whose digital outputs are
internally coupled to CMOS logic circuitry that decodes signal speed
and direction. Extremely low-drift BiCMOS circuitry is used for the
amplifiers to ensure symmetry between the two latches so that signal
quadrature can be maintained. An on-chip voltage regulator allows the
use of these devices from a 4.5 V to 18 V supply. Both devices have
standard open-collector outputs; the logic operation of both devices is
the same.
Two operating temperature ranges are provided; suffix ‘E–’ is for
the automotive and industrial temperature range of -40°C to +85°C,
suffix ‘L–’ is for the automotive and military temperature range of
-40°C to +150°C. The 5-pin ‘KA’ SIP package provides a cost-com-
petitive solution to linear magnetic sensing in harsh environments.
Data Sheet
27650.1
E1
E2
X
X
LOGIC
VCC
1
2
3
4
5
DIRECTION
GROUND
E1 OUTPUT
SUPPLY
Dwg. PH-015
Pinning is shown viewed from branded side.
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, V
CC
. . . . . . . . . . . . .
18 V
Magnetic Flux Density, B . . . .
Unlimited
Output OFF Voltage, V
OUT
. . . . . . . .
V
CC
Output Sink Current, I
OUT
. . . . . . .
30 mA
Package Power Dissipation,
P
D
. . . . . . . . . . . . . . . . . . . . . .
500 mW
Operating Temperature Range, T
A
Suffix ‘EKA’ . . . . . . .
-40˚C to +85˚C
Suffix ‘LKA’ . . . . . .
-40˚C to +150˚C
Storage Temperature Range,
T
S
. . . . . . . . . . . . . . .
-65˚C to +170˚C
SPEED
FEATURES
I
I
I
I
Internal Direction-Decoding Circuitry
Two Matched Hall Latches On A Single Substrate
Superior Temperature Stability
4.5 V to 18 V Operation
Electrically Defined Power-On State
Under-Voltage Lockout
Always order by complete part number, e.g.,
A3421EKA
.
3421
AND
3422
HALL-EFFECT,
DIRECTION-DETECTION
SENSORS
MAGNETIC CHARACTERISTICS over operating voltage range.
A3421xKA
Characteristic
Operate Point
Symbol
B
OP
Test Conditions
T
A
= -40°C
T
A
= +25°C
T
A
= Maximum
Release Point
3
B
RP
T
A
= -40°C
T
A
= +25°C
T
A
= Maximum
Hysteresis
B
hys
T
A
= -40°C
T
A
= +25°C
T
A
= Maximum
Operate Differential
Release Differential
B
OP1
- B
OP2
B
RP1
- B
RP2
Min.
140
130
120
-300
-280
-260
280
260
240
—
—
Typ.
185
160
—
-190
-175
—
375
335
—
—
—
Max.
300
280
260
-140
-130
-120
—
—
—
±80
±80
Min.
—
—
—
-85
-75
-75
10
10
10
—
—
A3422xKA
Typ.
29
29
—
-19
-18
-16
48
46
—
—
—
Max.
85
75
75
—
—
—
—
—
—
±60
±60
Units
G
G
G
G
G
G
G
G
G
G
G
NOTES:1. Magnetic flux density is measured at most sensitive area of device,
nominally located 0.014” (0.37 mm) below the branded face of the package.
2. Typical Data is at V
CC
= 12 V and T
A
= +25°C and is for design information only.
3. As used here, negative flux densities are defined as less than zero (algebraic convention).
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
Analogue and Mixed Signal
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