Allegro MicroSystems, Inc. has released a new dual-channel, Hall-effect direction detection sensor IC, providing various digital output signals that indicate speed and direction of a target rotation. The Hall elements are photolithographically aligned to better than 1 μm. Maintaining accurate mechanical location between the two active Hall elements eliminates the major manufacturing hurdle encountered in fine-pitch detection applications. The A1233 is a highly sensitive, temperature stable magnetic sensing device well suited for use in ring magnet based, speed and direction systems located in harsh automotive and industrial environments.
Allegro’s A1233 monolithic integrated circuit (IC) contains two independent Hall-effect bipolar switches located 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. The Allegro patented, high-frequency chopper-stabilization technique cancels offsets in each channel providing stable operation over the full specified temperature and voltage ranges.
Additionally, the high-frequency chopping circuits allow an increased analog signal-to-noise ratio at the input of the digital comparators internal to the IC. As a result, the A1233 achieves digital output jitter performance that is critical in high performance motor commutation applications. An on-chip low dropout (LDO) regulator allows the use of this device over a wide operating voltage range. Post-assembly factory programming at Allegro provides sensitive switchpoints that are symmetrical between the two switches.
The A1233 is available in a plastic 8-pin SOIC surface mount package (L) and a plastic 4-pin SIP (K). Both are available in a temperature range of –40°C to 150°C. Each package is lead (Pb) free, with 100 percent matte tin plated leadframe. Both the A1233LK-T and A1233LLTR-T are priced at $0.92 in quantities of 1,000.