A1174 Datasheet | Allegro MicroSystems

Ultrasensitive Hall Effect Latch with Internally or Externally Controlled Sample and Sleep Periods for Track Ball and Scroll Wheel Applications Features and Benefits - Micro-power latch operation - 1.65 to 3.5 V battery operation - Push-pull output eliminates the need for an external pull- up resistor - User configured, internally or externally controlled sample and sleep periods ▫ Floating the two clock pins results in the use of a fixed sampling clock internal to the device ▫ Toggling the clock pins allows the user to control the sampling and sleep times of the device for extreme low power operation - External control of the clock pins allows the user to implement synchronous sampling of multiple sensors in direction detection systems - Chopper stabilization ▫ Superior temperature stability ▫ Extremely low switchpoint drift ▫ Insensitive to physical stress - Solid state reliability - Small size Package: 6-contact MLP/DFN (suffix EW) 1.5 mm × 2 mm × 0.40 mm Description The A1174 is a micro-power, Hall-effect latch for use in portable devices that employ rotational detection systems, and have a power supply voltage between 1.65 and 3.5 V. The device has a single push-pull output structure and requires no external pull-up resistor for reliable operation. When a sufficient positive magnetic field is present on the device, the device output transitions to the low state and is latched in this state until a negative field of sufficient strength latches the device output into the high state. The latched output is ideal when using multiple sensors in rotational speed and direction sensing systems (for example, track ball and scroll bar systems in portable devices). The device includes an innovative clocking scheme that satisfies the micro-power needs of almost any application, including track balls for PDAs and cell phones. Using the EXTERNAL_CLK and DUAL_CLK pins as described in this datasheet, the device can be set into various working modes. In Dual Clock mode,...