Features: Omnipolar operation
Chopper stabilization
Superior temperature stability
Extremely low switchpoint drif
Insensitive to physical stress
Reverse battery protectio
Output short circuit protection
Solid state reliability
Small size
Robust EMC capability
High ESD ratings (HBM)SpecificationsSupply Voltage, VCC ..........................................28 V
Reverse-Supply Voltage, VRCC .......................18 V
Reverse-Supply Current, IRCC .......................2 mA
Output Off Voltage, VOUT...................................28 V
Output Current, IOUTSINK............. Internally Limited
Magnetic Flux Density, B .......................... ..Unlimited
Operating Temperature
Ambient, TA, Range E........................40ºC to 85ºC
Ambient, TA, Range L......................40ºC to 150ºC
Maximum Junction, TJ(MAX)............................ .165ºC
Storage Temperature, TS ................65ºC to 170ºCDescriptionThe A3245 integrated circuit is an omnipolar, ultrasensitive Hall-effect switch with a digital output. This sensor has an integrated regulator permitting operation to 24 V, making it the first omnipolar switch available for operation to 24 V. This device A3245 is especially suited for operation over extended temperature ranges, up to +150°C. Superior high-temperature performance is made possible through an Allegro® patented dynamic offset cancellation, which reduces the residual offset voltage normally caused by device overmolding, temperature excursions, and thermal stress.
The A3245 Hall-effect switch includes the following on a single silicon chip: voltage regulator, Hall-voltage generator, small-signal amplifier, chopper stabilization, Schmitt trigger, and a short circuit protected open-drain output. Advanced BiCMOS wafer fabrication processing is used to take advantage of low-voltage requirements, component matching, very low input-offset errors, and small component geometries.
The omnipolar operation of the A3245 allows activation with either a north or a south polarity field of sufficient strength. In the absence of a magnetic field, the output is off. This patented magnetic-polarity-independence feature makes this device an excellent replacement for reed switches, with improved ease of manufacturing, because the A3245 does not require manufacturers to orient their magnets. These devices allow simple on/off switching in industrial, consumer, and automotive applications.
The A3245 is rated for operation between the ambient temperatures 40°C and 85°C for the E temperature range, and 40°C to 150°C for the L temperature range. The small geometries of the BiCMOS process allow these devices to be provided in ultrasmall packages. The package styles available provide magnetically optimized solutions for most applications. Package LH is an SOT23W, a miniature low-profile surface-mount package, while package UA is a three-lead ultramini SIP for through-hole mounting. Each package is available in a lead (Pb) free version, with 100% matte tin plated leadframes.
A3245 Data Sheet
