AK8778B

[AK8778B] AK8778B Hall Effect IC for Pulse Encoders Overview The AK8778B is a Hall effect latch which detects both “vertical magnetic field” and “horizontal magnetic field” (perpendicular and parallel to the marking side of the package) at the same time. The pulse output F and direction output D are switched according to the vertical and horizontal magnetic fields applied to the device. The direction is calculated internally and output D is switched at a rising or falling edge of output F. The AK8778B is for use in the incremental pulse encoders or rotational detection systems. Features      4.0 to 24V supply voltage operation Sensitivity (Vertical, Horizontal) : ±1.7mT(Typ.) Two outputs : F (Pulse), D (Direction) Small package: SOP-6pin Halogen free MS1466-E-00 1 September 2012 Free Datasheet http://www.datasheet4u.com/ [AK8778B] Block Diagram VDD REGULATOR BIAS OSC 0.1mF VSS VREG HE_DRIVE TIMING LOGIC F CHOPPER_SW LATCH & LOGIC CHOP_AMP COMP D HALL SENSORS Figure 1. Block diagram Circuit Configuration Table 1. Circuit configuration Block REGULATOR HALL SENSORS CHOPPER_SW CHOP_AMP COMP BIAS HE_DRIVE OSC TIMING LOGIC LATCH & LOGIC Function Generate internal operating voltage. Two Hall elements fabricated by CMOS process. Perform chopping in order to cancel the offset of Hall sensor. Amplifies two Hall sensor output voltage with summation and subtraction circuit. Hysteresis comparator. Generates bias current to internal circuits. Generates bias current...