Description
The A3423 is a dual-channel Hall-effect sensor IC ideal for
use in speed and direction sensing applications incorporating
encoder ring-magnet targets. The A3423 provides various output
signals that indicate speed and direction of target rotation. The
Hall elements are both photolithographically aligned to better
than 1 m. Maintaining accurate displacement between the two
active Hall elements eliminates the major manufacturing hurdle
encountered in fine-pitch detection applications. The A3423 is
a highly sensitive, temperature-stable magnetic device ideal for
use in harsh automotive and industrial environments.
The Hall elements of the A3423 are spaced 1.63 mm apart,
which provides excellent speed and direction information
for small-geometry targets. Extremely low-drift amplifiers
guarantee symmetry between the switches to maintain signal
quadrature. An on-chip regulator allows the use of this device
over a wide operating voltage range of 3.8 to 24 V.
End-of-line trimming of the Hall element switchpoints provides
tight matching capability. The continuous-time nature of the
Hall elements delivers a fast start-up of the device and low
noise.
The A3423 has integrated protection against transients on
the supply and output pins and short-circuit protection on all
outputs.
The A3423 is available in a 4-pin SIP and a plastic 8-pin
SOIC surface mount package (the SOIC version is currently
in development). Both packages are lead (Pb) free, with 100%
matte tin leadframe plating.
A3423-DS, Rev. 5
Features and Benefits
Precisely aligned dual Hall elements
Tightly matched magnetic switchpoints
Speed and direction outputs
Individual Hall element outputs (L package)
Fast power-on time
Output short circuit protection
Operation from an unregulated power supply
Wide operating temperature range
Wide operating voltage range
Integrated EMC-ESD protection
Functional Block Diagram
Not to scale
A3423
Packages
8-pin SOIC (suffix L)
4-pin SIP (suffix K)
Dual Channel Hall Effect Direction Detection Sensor IC
Trim
Output
Current
Limit
Output
Current
Limit
Output
Current
Limit
Direction
Logic
Output
Current
Limit
Regulator
Power-on
Logic
E1
GND
VCC
E2
L package only
L package only
OUTA
OUTB
SPD
DIR
