A3423

• Precisely aligned dual Hall elements
• Tightly matched magnetic switchpoints
• Speed and direction outputs
• Individual Hall element outputs (L package)
• Fast power-on time
• Output short circuit protection
• Operation from an unregulated power supply
• Wide operating temperature range
• Wide operating voltage range
• Integrated EMC-ESD protection

The A3423 is a dual-channel Hall-effect sensor ideal for use in speed and direction sensing applications incorporating encoder ring-magnet targets. The A3423 provides various output signals that indicate speed and direction of target rotation. The Hall elements are both photolithographically aligned to better than 1 µm. Maintaining accurate displacement between the two active Hall elements eliminates the major manufacturing hurdle encountered in fine-pitch detection applications. The sensors are highly sensitive, temperature-stable magnetic sensors ideal for use in harsh automotive and industrial environments.

The Hall elements of the A3423 are spaced 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. An on-chip regulator allows the use of this device over a wide operating voltage range of 3.8 to 24 V.

End-of-line trimming of the Hall element switchpoints provides tight matching capability. The continuous-time nature of the Hall elements delivers a fast start-up of the sensor and low noise.

The A3423 has integrated protection against transients on the supply and output pins and short-circuit protection on all outputs.

The A3423 is available in a 4-pin SIP and a plastic 8-pin SOIC surface mount package (the SOIC version is currently in development). Both packages are lead (Pb) free, with 100% matte tin leadframe plating.