1 General description

The NMH1000 is a hall effect magnetic field switch. The switch is most sensitive to a vertical field passing

through the top-to-bottom surfaces, orthogonal to the plane of the application printed circuit board. The switch

operates at low voltage, low current, low output data rate, and is a small physical size.

Processing of input consists of functional blocks such as a configurable state machine, analog-to-voltage

conversion of the input, and comparison to generate the bi-state output, arranged in linear succession.

2 Features and benefits

• Threshold selection 3-state hardware pin.

• Threshold selection data bit(s) in an I2C accessible register.

• Sample rate selection 3-state hardware pin.

• Sample rate selection data bit(s) in an I2C accessible register.

• Mode selection hardware pin to select between standalone or I2C serial interface.

• Mode selection data bit(s) in an I2C accessible register.

• Two types of output indicate the absence of a magnetic field as compared to an internally set threshold:

– Binary state hardware pin.

– Binary state data bit(s), configurable as assert-high or assert-low, in an I2C accessible register.

3 Applications

• Electronic system wake-up: Detecting the proximity vs. lack of proximity to an included magnet when the

electronics are removed from its delivery packaging, to wake up the electronics.

• Laptop lid open / closed: Detecting the proximity vs. lack of proximity to a magnet mounted to laptop lid, to

trigger a status change, for example turn on / off the display.

• Door or window open / closed: Detecting the proximity vs. lack of proximity to a magnet mounted to a door,

lid, or window, to trigger a status change, for example an alarm.