Dual element devices are integrated circuits that contain two independent Hall-effect switches. The digital outputs are out-of-phase (quadrature) when interfaced with the proper ring magnet design.
These quadrature signals can be processed to determine target speed and direction. Alternately, the A1232 and A1233 internally process these switch outputs into speed and direction signals. The revolutionary A1262 uses a combination of vertical and planar Hall elements to sense in two dimensions (2D), delivering near-ideal quadrature signals independent of the magnet pole pitch. This, combined with its small size, greatly simplifies system design.
Extremely low-drift amplifiers guarantee symmetry between the switches to maintain signal quadrature. The Allegro high-frequency, chopper stabilization technique cancels offsets in each channel, providing stable operation over the full specified temperature and voltage ranges, and industry-leading digital output jitter performance that is critical in high-performance motor commutation applications.
|Device||Outputs||BOP/RP (G)||Hall Spacing (mm)||Sensing||Packages|
|A1230||A, B (quadrature)||±30||1.0||Dual Planar||SIP, SOIC|
|A1232||Speed, Direction||±30||1.63||Dual Planar||TSSOP-8|
||Speed, Direction||±55||1.63||Dual Planar||SIP|
A, B (quadrature)
|A1262||A, B (quadrature)||±17||0*||Planar + Vertical||SOT23-5|
|* Quadrature achieved by vertical and planar halls sensing fields 90 degrees apart.|
The following dual-element switches have been discontinued: A3423