HMC6052 Datasheet, PDF (6/6 Pages) List of Unclassifed Manufacturers – INTEGRATED COMPASS SENSOR

HMC6052
supply during the sensor circuit’s operation. The supply current can be effectively reduced by “duty cycling” DO2 and
making “snapshot” measurements during the sensor’s on time.
For example, a 3.0-volt lithium watch battery may have a typical 150mA-hour energy capacity rating. With the reference
design drawing about 15mA continuously, only 10 hours of operational time results. By placing the microcontroller and
HMC6052 into sleep mode 99% of the time, the total battery life extends to 1000 hours. Even greater efficiencies can be
had if the host microprocessor only toggles on DO2 for a few milliseconds, makes the analog to digital conversions of
outputs OUTA and OUTB, and then pulls DO2 high to sleep the HMC6052 until the next required measurement update.
The analog outputs of the HMC6052 circuit (OUTA, OUTB) are representative voltages proportional to the magnetic field
imposed on sensor bridges A and B. The sensor bridges have orthogonal axis of sensitivity and create a two dimensional
representation of the magnetic field’s strength and direction. When oriented nearly level with the ground, the outputs can
then be used for electronic compassing by sensing the horizontal components of the earth’s magnetic field. Using
onboard Analog-to-Digital Converters (ADCs) within the host microprocessor, the digital representations of north-pole
magnetic field direction can be related to the host platform (watch, phone, PDA, vehicle, ship, aircraft, etc.).
The outputs of the HMC6052 are referenced to approximately half of the supply voltage applied across pins 11
(VSUPPLY) and 12 (GND). With no other errors accounted for, OUTA (pin 13) and OUTB (pin 14) would be close to 1.5
volts with no magnetic field applied (completely shielded) and a supply voltage of 3-volts. If the shielding were removed
and a nominal earth’s magnetic field applied of 300 milli-gauss and –100 milli-gauss to sensor bridges A and B
respectively, OUTA would move positively from 1.5 volts and OUTB would move negatively from 1.5 volts. Neglecting
offset errors and using a nominal sensitivity of 0.5 volts per gauss, OUTA would be at about 1.65 volts and OUTB would
be at about 1.45 volts.
Using the above example values of earth’s field excitation, a host microprocessor with onboard 10-bit ADCs could provide
1024 increments (or counts) across the nominal zero to 3-volt supply voltage. If count 512 (about 1.5 volts) is referenced
as the zero gauss point, the 1.65 and 1.45 volt OUTA and OUTB levels convert to counts 563 and 495 respectively.
Without compensating for offset errors and calibration factors, the magnetic vectors for outputs A and B would be 51 and
–17 counts with respect to the zero field level count. In electronic compassing, the arctangent (B/A) is computed by the
microprocessor, resulting in a heading of about 341 degrees (19 degrees west of magnetic north).
For details on offset correction, calibration, and electronic compass heading computation using microprocessors, please
visit www.magneticsensors.com, and browse the technical papers and application notes in the applications section.
ORDERING INFORMATION
Ordering Number
HMC6052
Product
Integrated Compass Sensor
Find out more
For more information on Honeywell’s Magnetic Sensors visit us online at www.magneticsensors.com or contact us at
800-323-8295 (763-954-2474 internationally).
The application circuits herein constitute typical usage and interface of Honeywell product. Honeywell does not warranty or assume liability of customer-
designed circuits derived from this description or depiction.
Honeywell reserves the right to make changes to improve reliability, function or design. Honeywell does not assume any liability arising out of the
application or use of any product or circuit described herein; neither does it convey any license under its patent rights nor the rights of others.
U.S. Patents 4,441,072, 4,533,872, 4,569,742, 4,681,812, 4,847,584 and 6,529,114 apply to the technology described
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