AS5045B-ASST ams

AS5045B 12-Bit Programmable Magnetic Position Sensor Two digital 12-bit absolute outputs: 1 General Description - Serial interface - Pulse width modulated (PWM) output The AS5045B is a contact less magnetic position sensor for accurate angular measurement over a full turn of 360 degrees. Quadrature A/B/I output 12-bit It is a system-on-chip, combining integrated Hall elements, analog User programmable zero position front end and digital signal processing in a single device. Failure detection mode for magnet placement, monitoring, and To measure the angle, only a simple two-pole magnet, rotating over loss of power supply the center of the chip, is required. The magnet can be placed above Red-Yellow-Green indicators display placement of magnet in Z- or below the IC. axis The absolute angle measurement provides instant indication of the Serial read-out of multiple interconnected AS5045B devices magnets angular position with a resolution of 0.0879 = 4096 using Daisy Chain mode positions per revolution. This digital data is available as a serial bit stream and as a PWM signal. Tolerant to magnet misalignment and gap variations An internal voltage regulator allows the AS5045B to operate at either Wide temperature range: - 40C to +125C 3.3V or 5V supplies. Small Pb-free package: SSOP 16 (5.3mm x 6.2mm) 3 Applications 2 Key Features Contact less high resolution rotary position sensor over a full The device is ideal for industrial applications like automatic or turn of 360 degrees elevator doors, robotics, motor control and optical encoder replacement. Figure 1. Blockdiagram Rotary Position Sensor IC VDD3V3 MagINCn MagDECn VDD5V LDO 3.3V PWM PWM Interface Sin Ang ATAN DO Absolute (Cordic) Cos Mag Hall Array Interface CSn & (SSI) Frontend CLK Amplifier OTP PDIO Register A Incremental B Interface AS5045B I www.ams.com Revision 1.0 1 - 33AS5045B Datasheet - Contents Contents 1 General Description .................................................................................................................................................................. 1 2 Key Features............................................................................................................................................................................. 1 3 Applications............................................................................................................................................................................... 1 4 Pin Assignments ....................................................................................................................................................................... 3 4.1 Pin Descriptions.................................................................................................................................................................................... 3 5 Absolute Maximum Ratings ...................................................................................................................................................... 5 6 Electrical Characteristics........................................................................................................................................................... 6 6.1 Magnetic Input Specification................................................................................................................................................................. 7 6.2 System Specifications .......................................................................................................................................................................... 8 7 Timing Characteristics ............................................................................................................................................................ 10 8 Detailed Description................................................................................................................................................................ 11 8.1 Synchronous Serial Interface (SSI) .................................................................................................................................................... 11 8.2 Incremental Mode............................................................................................................................................................................... 13 8.3 Daisy Chain Mode .............................................................................................................................................................................. 14 8.4 Pulse Width Modulation (PWM) Output.............................................................................................................................................. 15 8.4.1 Changing the PWM Frequency.................................................................................................................................................. 16 8.5 Analog Output..................................................................................................................................................................................... 16 9 Application Information ........................................................................................................................................................... 17 9.1 Programming the AS5045B................................................................................................................................................................ 17 9.1.1 Zero Position Programming ....................................................................................................................................................... 17 9.1.2 OTP Memory Assignment.......................................................................................................................................................... 18 9.1.3 User Selectable Settings ........................................................................................................................................................... 18 9.1.4 OTP Default Setting................................................................................................................................................................... 19 9.1.5 Redundancy............................................................................................................................................................................... 19 9.1.6 Redundant Programming Option ............................................................................................................................................... 20 9.1.7 OTP Register Entry and Exit Condition ..................................................................................................................................... 20 9.2 Alignment Mode.................................................................................................................................................................................. 21 9.3 3.3V / 5V Operation............................................................................................................................................................................ 22 9.4 Selecting Proper Magnet.................................................................................................................................................................... 22 9.4.1 Physical Placement of the Magnet ............................................................................................................................................ 23 9.4.2 Magnet Placement..................................................................................................................................................................... 24 9.5 Failure Diagnostics............................................................................................................................................................................. 24 9.5.1 Magnetic Field Strength Diagnosis............................................................................................................................................ 24 9.5.2 Power Supply Failure Detection ................................................................................................................................................ 24 9.6 Angular Output Tolerances................................................................................................................................................................. 24 9.6.1 Accuracy.................................................................................................................................................................................... 24 9.6.2 Transition Noise......................................................................................................................................................................... 26 9.6.3 High Speed Operation ............................................................................................................................................................... 26 9.6.4 Propagation Delays ................................................................................................................................................................... 26 9.6.5 Internal Timing Tolerance .......................................................................................................................................................... 27 9.6.6 Temperature .............................................................................................................................................................................. 27 9.6.7 Accuracy over Temperature ...................................................................................................................................................... 27 10 Package Drawings and Markings ......................................................................................................................................... 28 10.1 Recommended PCB Footprint.......................................................................................................................................................... 30 11 Ordering Information ............................................................................................................................................................. 32 www.ams.com Revision 1.0 2 - 33