Micropower switches are integrated Hall-effect sensor ICs designed specifically for use in battery-operated devices, providing low power consumption for longer battery life. They are typically used for on/off switches (open/close) in cellular flip-phones, PDAs, and laptop computers, or for detecting motion or tampering in utility meters.
During operation (awake mode), these ICs compare the actual magnetic field detected with the internally compensated thresholds and switch the output on in the presence of sufficient magnetic field. During sleep mode, the output stage is latched. Current consumption is significantly reduced by cycling the awake and sleep periods.
The switching behavior of micropower switches is omnipolar, which means they can be switched on with either the North or South pole of a magnet.
Allegro offers unique 3D omnipolar sensor ICs that can detect magnetic fields of either polarity and in any direction. They are highly sensitive, making them ideal for detecting tampering via magnetic fields in applications such as smart meters, ATMs, gambling/gaming machines, ticket machines, electronic locks, etc. They can also be used as highly flexible proximity sensors, as they are insensitive to magnet orientation/direction.
|Micropower Switches (1D)|
|Part Number||Operating Voltage (V)||Operate Point (G)||Release Point (G)||Hysteresis (G)||Temp. Ranges||Packages||Supply Current (µA)|
|A1171||1.65 to 3.5||±55||±6||Typ 6||E||EW||4 (typ)
(VDD= 1.8 V)
|A3211||2.5 to 3.5||±55||±10||Typ 7.7||E||EL, EH, LH||6 (typ)|
|A3212||2.5 to 3.5||±55||±10||Typ 7.7||E||EL, EH, LH, UA||6 (typ)|
|A3213||2.4 to 5.5||±70||±10||Typ 7.7||E, L||LH, UA||850 (max)|
|A3214||2.4 to 5.5||±70||±10||Typ 7.7||E, L||LH, UA||22 (max)|
|Micropower Switches (3D)|
|A1266||2.5 to 5.5||±25||±17.5||7.5||E||LH||7.5 (typ) @ 2.5 V|
Temperature range codes: S = -20°C to 85°C, E = -40°C to 85°C, K = -40°C to 125°C, L = -40°C to 150°C