The A3211 and A3212 integrated circuits are ultra-sensitive, pole independent Hall-effect switches with latched digital output. These sensors are especially suited for operation in battery-operated, hand-held equipment such as cellular and cordless telephones, pagers, and palmtop computers.
The A3211 and A3212 are micropower, ultra‑sensitive Hall‑effect switches that operate from 2.5 V to 3.5 V and consume less than 15 µW average power. They feature chopper‑stabilized offset cancellation, high ESD protection, and a latched digital output that can sink up to 1 mA. Both devices are pole‑independent, allowing operation with either north or south magnetic polarity.
These switches are intended for battery‑operated handheld equipment such as cellular phones, pagers, and palmtop computers. They are offered in four surface‑mount and through‑hole packages (EH, EL, LH, UA) with lead‑free options, and are compatible with standard Hall‑effect sensor application notes provided by Allegro.
| Supply Voltage Range | 2.75 V – 3.5 V |
|---|---|
| Supply Current (Enabled) | 2.0 mA |
| Supply Current (Disabled) | 8.0 µA |
| Output Leakage Current | < 1.0 µA |
| Output On Voltage | 100 mV – 300 mV |
| Awake Time | 45 µs – 90 µs |
| Period | 45 ms – 90 ms |
| Chopping Frequency | 340 kHz |
| Hysteresis | 5.9 G |
| Operating Temperature (A3211) | -40 °C to 85 °C |
| Operating Temperature (A3212) | -40 °C to 150 °C |
They operate from 2.75 V up to 3.5 V.
Typical supply current is 2.0 mA when the chip is awake.
The output can sink up to 1 mA.
The hysteresis is about 5.9 gauss.