Honeywell HMC5843 User Manual

4

3-Axis Magnetoresistive Sen

sors

and

4

Small Size for

Highly Integrated Products. Just Add a Micro

-

4

Low Cost

4Designed for High Volume, Cost Sensitive OEM Designs

4

4.0 x

4.0 x 1.3mm

Low He

ight Profile

4

Easy to Assemble & Compatible with High Speed SMT Assembly

4

Low Voltage Operations (

2.5

to 3.3V)

4Compatible for Battery Powered Applications

4

Built-In S

trap Drive Circuit

s

4S

et/Reset

and Offset Stra

p Drivers

for Degaussing,

Self Test, and

4

I2C Digital Interface

4Popular Two

-

Wire Serial Data Interface for Consumer Electronics

4Lead Free Package Construction

4Complies with Current Environmental Standards

4

Wide

Magnetic Field Range (+/

-

6 Oe)

4Sensor

s Can Be Used in Strong Magnetic Field Environments

4

Available in Tape & Reel Packaging

4High Volume OEM Assembly

3-Axis Digital Compass IC HMC5843

The Honeywell HMC5843 is a surface mount multi-chip module designed for low field magnetic sensing with a digital interface for applications such as low cost compassing and magnetometry. The HMC5843 includes our state of the art 1043 series magneto-resistive sensors plus Honeywell developed ASIC containing amplifi cation, strap drivers, offset cancellation, 12-bit ADC and an I2C serial bus interface. The HMC5843 is in a 4.0 by 4.0 by 1.3mm surface mount leadless chip carrier (LCC). Applications for the HMC5843 include Consumer Electronics, Auto Navigation Systems, Personal Navigation Devices, and Magnetometers.

The HMC5843 utilizes Honeywell’s Anisotropic Magnetoresistive (AMR) technology that provides advantages over other magnetic sensor technologies. The sensors feature precision in-axis sensitivity and linearity, solid-state construction with very low cross-axis sensitivity designed to measure both direction and magnitude of Earth’s magnetic fields, from tens of micro-gauss to 6 gauss. Honeywell’s Magnetic Sensors are among the most sensitive and reliable low-field sensors in the industry.

Honeywell continues to maintain product excellence and performance by introducing innovative solid-state magnetic sensor solutions. These are highly reliable, top performance products that are delivered when promised. Honeywell’s magnetic sensor solutions provide real solutions you can count on.

FEATURES BENEFITS

ASIC in a Single Package

LCC Surface Mount Package

Controller Interface, Plus Two External SMT Capacitors

Offset Compensation

HMC5843

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SPECIFICATIONS (* Tested at 25°C except stated otherwise. )

Characteristics Conditions* Min Typ Max Units

Power Supply Supply Voltage AVDD Referenced to AGND

DVDD Referenced to DGND

Current Draw Sleep Mode (dual supplies)

Idle Mode (dual supplies)

Measurement Mode

AVDD = 2.5 volts, DVDD = 1.8 volts

Sleep Mode (single supply)

Idle Mode (single supply)

Measurement Mode

AVDD = 2.5 volts Performance Field Range Full scale (FS) – total applied field -4 +4 gauss Cross-Axis Sensitivity Cross field = 0.5 gauss,

Happlied = ±3 gauss

Disturbing Field Sensitivity starts to degrade.

Use S/R pulse to restore sensitivity. Max. Exposed Field No perming effect on zero reading 10000 gauss Measurement Period Output Rate = 50Hz (10Hz typ.) - 10 msec I2C Address 7-bit address

8-bit read address

8-bit write address I2C Rate Controlled by I2C Master -10 +10 % I2C bus pull-up Internal passive resistors 50 kilo-ohms I2C Hysteresis Hysteresis of Schmitt trigger inputs on SCL

and SDA - Fall (DVDD=1.8V)

Rise (DVDD=1.8V) Self Test Positive and Negative Bias Mode ±0.55 gauss Mag Dynamic Range 3-bit gain control ±0.7 ±1.0 ±4.0 gauss Linearity Full scale input range 0.1 ±% FS Gain Tolerance All gain/dynamic range settings ±5 % Bandwidth -3dB point 10 kHz Resolution AVDD=3.0V, GN 7 milli-gauss Signal-to Noise Ratio 70 dB Turn-on Time 200 us General ESD Voltage 700 V Operating Temperature Ambient -30 85 °C Storage Temperature Ambient, unbiased -40 125 °C Weight Nominal 50 milli-grams

2.5

1.6

-

±0.2% %FS/gauss

20 gauss

0x1E

1.8

2.5

240

0.8

110 340

0.9

0x3D 0x3C

0.603

1.108

3.3

2.0

-

hex

Volts Volts

uA uA

mA

uA uA

mA

hex hex

2

HMC5843

PIN CONFIGURATIONS

(Arrow indicates direction of applied field that generates a positive output voltage after a SET pulse.)

Pin Name Description

1 SCL Serial Clock – I2C Master/Slave Clock 2 SDAP Serial Data Pull-up Resistor – 50k-ohm to VDD 3 SCLP Serial Clock Pull-up Resistor – 50k-ohm to VDD 4 NC No Connection 5 NC No Connection 6 OFFP Offset Strap Positive 7 OFFN Offset Strap Negative 8 NC No Connection

9 SETP Set/Reset Strap Positive – S/R Capacitor (C2) Connection 10 SETN Set/Reset Strap Negative – Test Point 11 SVDD Sensor Supply – Test Point 12 DGND Digital Supply Ground/Return 13 C1 Reservoir Capacitor (C1) Connection 14 SETC S/R Capacitor (C2) Connection – Driver Side 15 DVDD Digital Positive Supply 16 VREN Voltage Regulator Enable, (GND = Dual Supply, AVDD = Single Supply) 17 AGND Analog Supply Ground/Return 18 AVDD Analog Positive Supply 19 DRDY Data Ready – Test Point 20 SDA Serial Data – I2C Master/Slave Data

Table 1: Pin Configurations

20

SDA

20

SDA

DRDY

19

18

AVDD

18

AVDD

AGND

17

16

VREN

16

VREN

SDAP

SCLP

SDAP

SETC

SCLP

X

C1

TP1

Z

DGND

TP0

1112131415

SVDD

SCL

1 2 3 4 5

Y

DVDD

HMC5843 – bottom view

10

6

OFFP

6

OFFP

7

OFFN

7

OFFN

8

NC

8

NC

9

SETP

9

SETP

SETN

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HMC5843

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PACKAGE OUTLINES

PACKAGE DRAWING HMC5843 (20-PIN LPCC, dimensions in millimeters)

Pin 1

D2 A

D3

Sym Min Nom Max

A 1.20 - 1.46 D 4.0 BSC

E2

E

L e

D

HMC5843 – bottom view

D2 2.25 D3 0.25 x 20 pins

E 4.0 BSC

E2 2.25

e 0.50 Basic L 0.40 x 20 pins

MOUNTING CONSIDERATIONS

The following is the recommend printed circuit board (PCB) footprint for the HMC5843.

PCB Pad Definition and Traces

The HMC5843 is a fine pitch LCC package with a 0.50mm pin pitch (spacing), with the pin pads defined as 0. 40mm by

0.25mm in size. PCB pads are recommended to be oversized by 0.025mm from each pad for a short dimension oversize of 0.05mm. The interior PCB pad is recommended to be 0.05mm oversized per pin with an exterior oversize of 0.20mm for proper package centering and to permit test probing. Size the traces between the HMC5843 and the external capacitors (C1 and C2) to handle the 1 ampere peak current pulses with low voltage drop on the traces.

Stencil Design and Solder Paste

A 4 mil stencil and 100% paste coverage is recommended for the electrical contact pads.

Pick and Place

Placement is machine depe ndant and no restrictions are recommended, and have been tested with mechanical centering. Placement force should be equivalent 1206 SMT resistors and enough force should be used to squeeze the paste out from the package/contact pad overlap and to keep the package pin contacts vertical.

Reflow and Rework

No special profile is required for the HMC5843 and compatible with lead eutectic and lead-free solder paste reflow profiles. Honeywell recommends the adherence to solder paste manufacturer’s guidelines. The HMC5843 may be reworked with soldering irons, but extreme care must be taken not to overheat the copper pads from the part’s fiberglass substrate. Irons with a tip temperature no greater than 315°C should be used. Excessive rework risks the copper pads pulling away into the molten solder.

4

HMC5843

INTERNAL SCHEMATIC DIAGRAM

HMC5843

DUAL SUPPLY REFERENCE DESIGN

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HMC5843

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SINGLE SUPPLY REFERENCE DESIGN

BASIC DEVICE OPERATION

Anisotropic Magneto-Resistive Sensors

The Honeywell HMC5843 magnetoresistive sensor circuit is a trio of sensors and application specific support circuits to measure magnetic fields. With power supply applied, the sensor converts any incident magnetic field in the sensitive axis directions to a differential voltage output. The magnetoresistive sensors are made of a nickel-iron (Permalloy) thin -film and patterned as a resistive strip element. In the presence of a magnetic field, a change in the bridge resistive elements causes a corresponding change in voltage across the bridge outputs.

These resistive elements are aligned together to have a common sensitive axis (indicated by arrows on the pinouts) that will provide positive voltage change with magnetic fields increasing in the sensitive direction. Because the output only is in proportion to the one -dimensional axis (the principle of anisotropy) and its magnitude, additional sensor bridges placed at orthogonal directions permit accurate measurement of arbitrary field direction.

Self Test

An offset strap is designed for self test function. The offset strap measures nominally 13 ohms, and requires 10mA for each gauss of induced field. The straps will easily handle currents to buck or boost fields through the ±4 gauss linear measurement range, but designers should note the extreme thermal heating on the sensor die when doing so.

6

HMC5843

DVDD

AVDD

Modes

Description

High High AGND

All, except

Internal voltage regulator: Disabled.

High Low AGND

Idle Internal voltage regulator: Disabled.

Internally

High AVDD

All, except

Internal voltage regulator: Enabled

Low Low -- Off Device in off mode.

Power Management

This device is capable of operating with a single supply (AVDD) or dual supplies (AVDD and DVDD). Pin VREN makes this selection by enabling the internal digital supply voltage regulator. When VREN is tied to AVDD, the device is in single supply operation; this device is powered from AVDD; and the internal voltage regulator is enabled. When VREN is tied to AGND this devices operates with both AVDD and DVDD as supplies. The table below shows the modes available at the various power supply conditions.

VREN

Supported

Off

regulated

Table 2: Operational Modes and Supply States

Note the continuous current draw versus data update rate in micro-amperes shown in the graph below. Under 10Hz, the current stays below 1mA.

Off

Digital I/O pins: Range from DGND to DVDD. Device fully functional. Digital logic blocks are

powered from DVDD supply, including all onboard clocks.

Digital I/O pins: Range from DGND to DVDD. Device Measurement functionality not supported.

Device I2C bus and register access supported.

Digital I/O pins: Range from AGND to AVDD Device fully functional. Digital logic blocks are

powered through on-board regulator.

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