The Allegro® A6850 interfaces a microprocessor with a pair of two-wire Hall-effect sensor ICs. The A6850 uses protected high-side, low-resistance DMOS MOSFETs to switch supply voltages to two Hall-effect devices. Each switch can be controlled individually via a single Enable pin, and both switches are protected by current limiting circuitry. The output switches are rated for operation at 26.5 V and will supply at least 25 mA per channel before current limiting.
Typically, two-wire Hall device applications require the user to measure the supply current to determine whether the Hall IC is on (presence of magnetic field) or off (absence of magnetic field). This is typically achieved by using an external serial shunt resistor and protection circuit using a microprocessor. In many systems, the sensed voltage is used as the input voltage to the analog to digital (A to D) input of the microprocessor. This provides an indication of the two-wire switching status of the system and diagnostic information to determine whether an open or shorted Hall device is present.
In combination with an integrated current mirror, the A6850 eliminates the need for an external serial shunt resistor in Hall device applications that reports Hall IC supply current as 1/10th of the value on the SENSE1 or SENSE2 output pin. A low-current "sleep" mode (
A6850Available in an ultra-thin 8-pin lead-free SOIC package with 100% matte tin leadframe plating.
- Operates between 4.75 and 26.5 V
- Low VINto VOUTPressure drop
- 1/10 current sense feedback
- It can withstand short-to-battery and short-to-ground faults
- Withstands a 40 V dump load
- 4 ESD rating is 4 kV on the output pin, compared to 2 kV on all other pins
- Output current limit
- Low operating and sleep mode currents
- Integration with Allegro A114X and A118X Hall-effect two-wire sensor ICs