A1642LK Datasheet, PDF (1/13 Pages) Allegro MicroSystems – Two-Wire True Zero-Speed Miniature Differential Peak-Detecting Sensor with Continuous Calibration

A1642LK
Two-Wire True Zero-Speed Miniature Differential
Peak-Detecting Sensor with Continuous Calibration
Package K, 4-pin SIP
1234
1. VCC
2. No connection
3. Test pin (float or tie to GND)
4. GND
The A1642 is an optimized Hall effect sensing integrated circuit that provides a
user-friendly solution for true zero-speed digital ring-magnet sensing in two-wire
applications. This small package can be easily assembled and used in conjunction
with a wide variety of target shapes and sizes.
The integrated circuit incorporates a dual-element Hall effect sensor and signal
processing that switches in response to differential magnetic signals created by
ring magnet poles. The circuitry contains a sophisticated digital circuit to reduce
system offsets, to calibrate the gain for air-gap–independent switchpoints, and to
achieve true zero-speed operation. Signal optimization occurs at power-on through
the combination of offset and gain adjust and is maintained throughout the operat-
ing time with the use of a running-mode calibration. The running-mode calibration
allows immunity to environmental effects such as micro-oscillations of the target
or sudden air gap changes.
The regulated current output is configured for two-wire applications and the
sensor is ideally suited for obtaining speed and duty cycle information in ABS
(antilock braking systems). The 1.5 mm spacing between the dual Hall elements is
optimized for fine pitch ring-magnet-based configurations. For applications requir-
ing sensing of rotating ferrous gears and targets, refer to the ATS642LSH series of
products. The package is lead (Pb) free, with 100% matte tin leadframe plating.
ABSOLUTE MAXIMUM RATINGS
Supply Voltage, V_CC .......................................... 28 V
Reverse-Supply Voltage, V_RCC ........................ –18 V
Operating Temperature
Ambient, T_A,............................... –40ºC to 150ºC
Maximum Junction, T_J(max)........................165ºC
Storage Temperature, T_S .................. –65ºC to 170ºC
Features and Benefits
• Running mode calibration for continu-
ous optimization
• Single chip IC for high reliability
• Internal current regulator for 2-wire
operation
• Precise duty cycle signal over
operating temperature range
• Large operating air gaps
• Automatic Gain Control (AGC) for air
gap independent switchpoints
• Automatic Offset Adjustment (AOA)
for signal processing optimization
• True zero-speed operation
• Undervoltage lockout
• Wide operating voltage range
A1642LK-DS
Use the following complete part numbers when ordering:
Part Number
A1642LK-I1-T
A1642LKTN-I1-T
Packing*
Bulk, 500 pieces/bag
Tape and reel, 13-inch reel
4000 pieces/reel
I_CC Typical
6.0 Low to 14.0 High mA
A1642LK-I2-T
A1642LKTN-I2-T
Bulk, 500 pieces/bag
Tape and reel, 13-inch reel
4000 pieces/reel
7.0 Low to 14.0 High mA
*Contact Allegro for additional packing options.
Allegro MicroSystems, Inc.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 [phone]
www.allegromicro.com