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
碌m,
as
contrasted with 100
碌m
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 鈥楨鈥撯€?is for
the automotive and industrial temperature range of -40擄C to +85擄C,
suffix 鈥楲鈥撯€?is for the automotive and military temperature range of
-40擄C to +150擄C. The 5-pin 鈥楰A鈥?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 鈥楨KA鈥?. . . . . . .
-40藲C to +85藲C
Suffix 鈥楲KA鈥?. . . . . .
-40藲C to +150藲C
Storage Temperature Range,
T
S
. . . . . . . . . . . . . . .
-65藲C to +170藲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
.
1
2
3
4
5
6
7
8
9
10
11
12
