A3425_06 Datasheet, PDF (1/21 Pages) Allegro MicroSystems – Ultra-Sensitive Dual-Channel Quadrature Hall-Effect Bipolar Switch

A3425
Ultra-Sensitive Dual-Channel Quadrature
Hall-Effect Bipolar Switch
Features and Benefits
▪ Two matched Hall effect switches on a single substrate
▪ Sensor Hall element spacing approximately 1 mm
▪ Superior temperature stability
▪ 3.3 to 18 V operation
▪ Integrated ESD diode from OUTPUT and VCC pins
to GND
▪ High-sensitivity switchpoints
▪ Robust structure for EMC protection
▪ Solid-state reliability
Package: 8 pin SOIC (suffix L), and 4 pin
SIP (suffix K)
Description
The A3425 is a dual–output-channel, bipolar switch with
each channel comprising a separate complete Hall-effect
sensor circuit with dedicated Hall element and separate digital
output for speed and direction signal processing capability. The
independent Hall elements (E1 integrated with OUTPUTA, and
E2 integrated with OUTPUTB) are photolithographically aligned
to better than 1 μm. Maintaining this accurate mechanical
location between the two active Hall elements eliminates the
major manufacturing hurdle encountered in fine-pitch detection
applications.TheA3425 is a highly sensitive, temperature-stable
magnetic sensing device, which is ideal for use in ring magnet-
based speed and direction systems used in harsh automotive
and industrial environments.
The A3425 contains two independent Hall effect switches, and
has a monolithic IC that accurately locates the two Hall elements,
E1 and E2, approximately 1 mm apart. The digital outputs are
90º out of phase so that the outputs are in quadrature, with the
proper ring magnet design. This allows for easy processing of
speed and direction signals. Extremely low-drift amplifiers
guarantee symmetry between the switches to maintain signal
Not to scale
Continued on the next page…
Typical Application
V_Supply
100 Ω
2
OUTPUTA
1
A3425
3
VCC
OUTPUTB
GND
4
0.1 uF
VOUTPUTB
VOUTPUTA
A3425DS-Rev. 6
Using unregulated supply