The A17201 is an AC-coupled Hall-effect sensor IC which
includes monolithic integrated circuits that switch in response
to changing differential magnetic fields created by rotating ring
magnets or, when coupled with a magnet, by ferrous targets.
This device also includes an integrated tracking capacitor
that provides the high accuracy of analog sensing without an
external filter capacitor. This reduces cost and components,
while improving the reliability of the final sensor solution.
Magnetic field changes affect the two integrated Hall
transducers and then are differentially amplified on the chip.
Differential design provides immunity to radial vibration,
within the device operating air gap range, by rejection of this
common-mode signal change. Steady-state system offsets are
eliminated using an on-chip differential bandpass filter with
integrated capacitor. This filter also provides relative immunity
to interference from electromagnetic sources. The device uses
advanced temperature compensation for the high-pass filter,
sensitivity, and Schmitt trigger switchpoints to guarantee
optimal operation to low frequencies over a wide range of air
gaps and temperatures.
A17201-DS, Rev. 5
MCO-0000390
• Integrated tracking capacitor
• Integrated capacitor reduces requirements for external
EMI protection components (UB package)
• Used for sensing motion of ring magnet or ferrous targets
• Wide operating temperature range
• Operation with magnetic input signal frequency from
8 Hz to 20 kHz
• Large effective air gaps
• 3.5 to 24.0 V supply operating range
• Reverse battery protection
• Resistant to mechanical and thermal stress
Two-Wire AC-Coupled Differential Sensor IC
with Integrated Filter Capacitor
PACKAGES:
Figure 1: Functional Block Diagram
Not to scale
A17201
Continued on next page...
FEATURES AND BENEFITS DESCRIPTION
March 2, 2022
3-pin SIP,
matrix HD style
(suffix UA)
Hall
Amp
Regulator
Bandpass Filter Integrated
Tracking Capacitor
VCC
(Pin 1)
UA Package: GND (Pin 2 or Pin 3)
10 nF
(U
A Package Only)
V
S
+
Gain
Stage
Dual Hall
Transducers
Comparator
V
REF
Output
Control
UB Package: GND (Pin 2)
2-pin SIP
(suffix UB)
Two-Wire AC-Coupled Differential Sensor IC
with Integrated Filter Capacitor
A17201
2
Allegro MicroSystems
955 Perimeter Road
Manchester, NH 03103-3353 U.S.A.
www.allegromicro.com
ABSOLUTE MAXIMUM RATINGS
Characteristic Symbol Notes Rating Unit
Supply Voltage V
CC
28 V
Reverse Supply Voltage V
RCC
–18 V
Operating Ambient Temperature T
A
Range L –40 to 150 °C
Maximum Junction Temperature T
J(MAX)
165 °C
Storage Temperature T
stg
–65 to 170 °C
SELECTION GUIDE
Part Number Package Packing
[1]
Operating Ambient
Temperature Range,
T
A
(°C)
Supply Current
I
CC(LOW)
min I
CC(LOW)
max
A17201LUAA 3-pin through hole SIP Bulk, 500 pieces per bag –40 to 150 3 7
A17201LUBBTN 2-pin through hole SIP 4000 pieces per 13-inch reel –40 to 150 3 7
[1]
Contact Allegro for additional packing options.
DESCRIPTION (continued)
The device includes: a voltage regulator, two Hall transducers,
temperature compensating circuitry, a signal conditioning amplifier,
bandpass filter, Schmitt trigger, and an output control. The on-board
regulator permits operation with supply voltages from 3.5 to 24 V.
The regulated current output is configured for two-wire interface
circuitry and is ideally suited for obtaining speed information in
wheel speed applications. The device packages have an operating
ambient temperature range of –40°C to 150°C, and are provided in a
3-pin plastic SIP (suffix UA) or a 2-pin plastic SIP (suffix UB). Both
packages are lead (Pb) free, with 100% matte-tin-plated leadframes.