0.1 uF
100 Ω
1
A3425
2
3
4
V
Supply
VOUTPUTB
VOUTPUTA
OUTPUTA
OUTPUTB
GND
VCC
Using unregulated supply
Description
The A3425 is a dual–output-channel, bipolar switch with each
channel comprising a separate complete Hall-effect 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. The A3425 is a highly sensitive, temperature-stable
magnetic device, which is ideal for use in ring magnet-based
speed and direction sensing 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
A3425DS-Rev. 11
Features and Benefits
▪ Two matched Hall effect switches on a single substrate
▪ 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
Ultra-Sensitive Dual-Channel Quadrature
Hall-Effect Bipolar Switch
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Package: 8 pin SOIC (suffix L), and 4 pin
SIP (suffix K)
Typical Application
Not to scale
A3425
