A1174EEWLT-P

NOTE: For detailed information on purchasing options, contact your

local Allegro field applications engineer or sales representative.

Allegro MicroSystems, LLC reserves the right to make, from time to time, revisions to the anticipated product life cycle plan

for a product to accommodate changes in production capabilities, alternative product availabilities, or market demand. The

information included herein is believed to be accurate and reliable. However, Allegro MicroSystems, LLC assumes no respon-

sibility for its use; nor for any infringements of patents or other rights of third parties which may result from its use.

Recommended Substitutions:

Ultrasensitive Hall Effect Latch with Internally or Externally Controlled Sample

and Sleep Periods for Track Ball and Scroll Wheel Applications

Discontinued Product

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

datasheet, the device can be set into various working modes.

In Dual Clock mode, the device switches between predefined

slow and fast sampling rates. The average current consumption

of the device is extremely low when rotation is not detected.

In External Clock mode, the user sets the clock rate for the

device to achieve the required on and off times for controlling

average power. This user-determined clocking also helps to

A1174-DS, Rev. 7

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

Package: 6-contact MLP/DFN (suffix EW)

Figure 1. Timing diagram for output switching

2

Number Name Function

DFN/MLP 1.5

×

2 mm; 0.40 mm maximum height 3000 pieces per 7-inch reel

Contact Allegro

for additional packing options.

2Allegro products sold in DFN package types are not intended for automotive applications.

achieve synchronous clocking of multiple devices. This allows a

device in direction detection systems.

MOSFET output.

overall height MLP/DFN, with exposed pad for enhanced thermal

Absolute Maximum Ratings

V

I

–1 mA