AS5145H/AS5145A/ AS5145B 12-Bit Programmable Magnetic Rotary Encoder General Description The AS5145 is a contactless magnetic rotary encoder for accurate angular measurement over a full turn of 360 degrees. It is a system-on-chip, combining integrated Hall elements, analog front end and digital signal processing in a single device. To measure the angle, only a simple two-pole magnet, rotating over the center of the chip, is required. The magnet can be placed above or below the IC. The absolute angle measurement provides instant indication of the magnet’s angular position with a resolution of 0.0879º = 4096 positions per revolution. This digital data is available as a serial bit stream and as a PWM signal. An internal voltage regulator allows the AS5145 to operate at either 3.3V or 5V supplies. Ordering Information and Content Guide appear at end of datasheet. Key Benefits & Features The benefits and features of AS5145H/AS5145A/AS5145B, 12-Bit Programmable Magnetic Rotary Encoder are listed below: Figure 1: Added Value of Using AS5145 Benefits Features • Highest reliability and durability • Contactless high resolution rotational position encoding over a full turn of 360 degrees • Simple programming • Simple user-programmable zero position and settings • Multiple interfaces • Serial communication interface (SSI) • 10-bit pulse width modulated (PWM) output • Quadrature A/B and Index output signal • Ideal for motor applications • Rational speeds up to 30,000 rpm • Failure diagnostics • Failure detection mode for magnet placement monitoring and loss of power supply • Easy setup • Serial read-out of multiple interconnected AS5145 devices using Daisy Chain mode ams Datasheet [v2-00] 2016-Feb-05 Page 1 Document Feedback AS5145H/AS5145A/AS5145B − General Description Benefits Features • Great flexibility at a huge application area • Detects movement of magnet in Z-axis (Red-Yellow-Green indicator) • Fully automotive qualified • AEC-Q100, grade 0 • Small form factor • SSOP 16 (5.3mm x 6.2mm) • Robust environmental tolerance • Wide temperature range: -40°C to 150°C Applications The device is ideal for industrial applications like contactless rotary position sensing and robotics; automotive applications like steering wheel position sensing, transmission gearbox encoder, head light position control, torque sensing, valve position sensing and replacement of high end potentiometers. Block Diagram The functional blocks of this device are shown below: Figure 2: AS5145 Automotive Rotary Encoder IC VDD3V3 VDD5V MagINCn MagDECn LDO 3.3V PWM Interface Sin Hall Array & Frontend Amplifier Mux Cos PWM Ang DSP Mag Absolute Interface (SSI) DO CSn CLK OTP Register AS5145 PDIO Incremental Interface DTEST1_A DTEST2_B Mode_Index Page 2 Document Feedback ams Datasheet [v2-00] 2016-Feb-05 AS5145H/AS5145A/AS5145B − Pin Assignment Pin Assignment Figure 3: Pin Diagram (Top View) 1 16 VDD5V MagDECn 2 15 VDD3V3 DTest1_A 3 14 NC DTest2_B 4 13 NC NC 5 12 PWM Mode_Index 6 11 CSn VSS 7 10 CLK PDIO 8 9 DO AS5145 MagINCn Pin Description The following SSOP16 shows the description of each pin of the standard SSOP16 package (Shrink Small Outline Package, 16 leads, body size: 5.3mm x 6.2mmm; (see Figure 3). Figure 4: Pin Description Pin Name Pin Number MagINCn 1 Pin Type Digital output open drain MagDECn 2 DTest1_A 3 Description Magnet Field Magnitude Increase. Active low. Indicates a distance reduction between the magnet and the device surface. (see Figure 15) Magnet Field Magnitude Decrease. Active low. Indicates a distance increase between the device and the magnet. (see Figure 15) Test output in default mode Digital output DTest2_B 4 NC 5 - Mode_Index 6 Digital input/output pull-down VSS 7 Supply pin ams Datasheet [v2-00] 2016-Feb-05 Test output in default mode Must be left unconnected Select between slow (open, low: VSS) and fast (high) mode. Internal pull-down resistor (10kΩ). Negative supply voltage (GND) Page 3 Document Feedback AS5145H/AS5145A/AS5145B − Pin Assignment Pin Number Pin Type Description PDIO 8 Digital input pull-down OTP Programming Input and Data Input for Daisy Chain Mode. Pin has an internal pull-down resistor (74kΩ). Connect this pin to VSS if programming is not required. DO 9 Digital output/ tri-state Data Output of Synchronous Serial Interface CLK 10 Digital input, Schmitt-Trigger input Clock Input of Synchronous Serial Interface; Schmitt-Trigger input CSn 11 Digital input pull-down, Schmitt-Trigger input Chip Select. Active low. Schmitt-Trigger input, internal pull-up resistor (50kΩ) PWM 12 Digital output NC 13 - Must be left unconnected NC 14 - Must be left unconnected VDD3V3 15 Supply pin 3V-Regulator output, internally regulated from VDD5V. Connect to VDD5V for 3V supply voltage. Do not load externally. VDD5V 16 Supply pin Positive supply voltage, 3.0V to 5.5V Pin Name Pulse Width Modulation Pin 1 and 2 are the magnetic field change indicators, MagINCn and MagDECn (magnetic field strength increase or decrease through variation of the distance between the magnet and the device). These outputs can be used to detect the valid magnetic field range. Furthermore those indicators can also be used for contactless push-button functionality. Pin 3 and 4 are multi function pins for sync mode, sine/cosine mode and incremental mode. Pin 6 Mode_Index allows switching between filtered (slow) and unfiltered (fast mode). In incremental mode, the pin changes from input to output and provides the index pulse information. A change of the mode during operation is not allowed. The setup must be constant during power up and during operation. Pins 7, 15, and 16 are supply pins, pins 5, 13, and 14 are for internal use and must not be connected. Pin 8 (PDIO) is used to program the zero-position into the OTP(see page 27). This pin is also used as digital input to shift serial data through the device in daisy chain configuration, (see page 18). Page 4 Document Feedback ams Datasheet [v2-00] 2016-Feb-05 AS5145H/AS5145A/AS5145B − Pin Assignment Pin 11 Chip Select (CSn; active low) selects a device within a network of AS5145 encoders and initiates serial data transfer. A logic high at CSn puts the data output pin (DO) to tri-state and terminates serial data transfer. This pin is also used for alignment mode (see Alignment Mode) and programming mode (see Programming the AS5145). Pin 12 allows a single wire output of the 12-bit absolute position value. The value is encoded into a pulse width modulated signal with 1μs pulse width per step (1μs to 4096μs over a full turn). By using an external low pass filter, the digital PWM signal is converted into an analog voltage, e.g. for making a direct replacement of potentiometers possible. ams Datasheet [v2-00] 2016-Feb-05 Page 5 Document Feedback AS5145H/AS5145A/AS5145B − Absolute Maximum Ratings Absolute Maximum Ratings Stresses beyond those listed in Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in Electrical Characteristics is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Figure 5: Absolute Maximum Ratings Parameter Min Max Units Comments Electrical Parameters DC supply voltage at pin VDD5V -0.3 DC supply voltage at pin VDD3V3 7 V 5 V Input pin voltage -0.3 VDD5V +0.3 V Input current (latchup immunity) -100 100 mA Except VDD3V3 EIA/JESD78 Class II Level A Electrostatic Discharge Electrostatic discharge ±2 kV JESD22-A114E Temperature Ranges and Storage Conditions Storage temperature -55 150 Package body temperature Relative humidity non-condensing Moisture sensitivity level (MSL) Page 6 Document Feedback 5 3 ºC Min -67ºF; Max 302ºF 260 ºC The reflow peak soldering temperature (body temperature) specified is in accordance with IPC/JEDEC J-STD-020 “Moisture/Reflow Sensitivity Classification for Non-Hermetic Solid State Surface Mount Devices”. The lead finish for Pb-free leaded packages is matte tin (100% Sn). 85 % Represents a maximum floor time of 168h ams Datasheet [v2-00] 2016-Feb-05 AS5145H/AS5145A/AS5145B − Electrical Characteristics Electrical Characteristics TAMB = -40ºC to 150ºC, VDD5V = 3.0V-3.6V (3V operation) VDD5V = 4.5V-5.5V (5V operation) unless otherwise noted. Figure 6: Electrical Characteristics Symbol Parameter Condition Min Typ Max Unit 150 ºC 16 21 mA 5.0 5.5 Operating Conditions TAMB Ambient temperature Isupp Supply current VDD5V Supply voltage at pin VDD5V VDD3V3 Voltage regulator output voltage at pin VDD3V3 VDD5V Supply voltage at pin VDD5V VDD3V3 Supply voltage at pin VDD3V3 VON Voff Version H/A/B -40 4.5 5V operation 3.3V operation (pin VDD5V and VDD3V3 connected) Power-on reset thresholds On voltage; 300mV typ. hysteresis Power-on reset thresholds Off voltage; 300mV typ. hysteresis V 3.0 3.3 3.6 3.0 3.3 3.6 V 3.0 3.3 3.6 1,37 2.2 2.9 DC supply voltage 3.3V (VDD3V3) V 1.08 1.9 2.6 Programming Conditions VPROG Programming voltage Voltage applied during programming 3.3 3.6 V VProgOff Programming voltage off level Line must be discharged to this level 0 1 V IPROG Programming current Current during programming 100 mA Programmed fuse resistance (log 1) 10μA max. current @ 100mV 10k ∞ Ω Unprogrammed fuse resistance (log 0) 2mA max. current @ 100mV 50 100 Ω Rprogrammed Runprogrammed ams Datasheet [v2-00] 2016-Feb-05 Page 7 Document Feedback AS5145H/AS5145A/AS5145B − Electrical Characteristics Symbol Parameter Condition Min Typ Max Unit DC Characteristics CMOS Schmitt-Trigger Inputs: CLK, CSn (CSn = Internal Pull-Up) VIH High level input voltage VIL Low level input voltage VIon- VIoff Normal operation 0.7 * VDD5V V 0.3 * VDD5V Schmitt Trigger hysteresis 1 V V ILEAK Input leakage current CLK only -1 1 IIL Pull-up low level input current CSn only, VDD5V: 5.0V -30 -100 μA DC Characteristics CMOS / Program Input: PDIO VIH High level input voltage VPROG(1) High level input voltage VIL Low level input voltage IIH High level input current During programming VDD5V: 5.5V 0.7 * VDD5V VDD5V V 3.3 3.6 V 0.3 * VDD5V V 100 μA 1 μA VSS + 0.4 V 30 DC Characteristics CMOS Output Open Drain: MagINCn, MagDECn IOZ Open drain leakage current VOL Low level output voltage IO Page 8 Document Feedback VDD5V: 4.5V 4 VDD5V: 3V 2 Output current mA ams Datasheet [v2-00] 2016-Feb-05 AS5145H/AS5145A/AS5145B − Electrical Characteristics Symbol Parameter Condition Min Typ Max Unit DC Characteristics CMOS Output: PWM VOH High level output voltage VOL Low level output voltage IO VDD5V – 0.5 V VSS +0.4 VDD5V: 4.5V 4 VDD5V: 3V 2 Output current V mA DC Characteristics CMOS Output: A, B, Index VOH High level output voltage VOL Low level output voltage IO VDD5V – 0.5 V VSS +0.4 VDD5V: 4.5V 4 VDD5V: 3V 2 Output current V mA DC Characteristics Tri-State CMOS Output: DO VOH High level output voltage VOL Low level output voltage IO IOZ VDD5V – 0.5 V VSS +0.4 VDD5V: 4.5V 4 VDD5V: 3V 2 Output current Tri-state leakage current V mA 1 μA Note(s): 1. Either with 3.3V or 5V supply. ams Datasheet [v2-00] 2016-Feb-05 Page 9 Document Feedback AS5145H/AS5145A/AS5145B − Electrical Characteristics Magnetic Input Specification TAMB = -40°C to 150°C, VDD5V = 3.0V to 3.6V (3V operation) VDD5V = 4.5 to 5.5V (5V operation) unless otherwise noted. Two-pole cylindrical diametrically magnetized source: Figure 7: Magnetic Input Specification Symbol Parameter dmag Diameter tmag Thickness Condition Recommended magnet: Ø 6mm x 2.5mm for cylindrical magnets Bpk Magnetic input field amplitude Required vertical component of the magnetic field strength on the die’s surface, measured along a concentric circle with a radius of 1.1mm Boff Magnetic offset Field non-linearity fmag_abs Input frequency (rotational speed of magnet) 4 6 Max Unit mm 2.5 mm mT Constant magnetic stray field ± 10 mT Including offset gradient 5 % 153 rpm @ 4096 positions/rev; fast mode 2.54 45 Hz 38 rpm @ 4096 positions/rev; slow mode 0.63 0.25 mm 100 μm Disp Displacement radius Ecc Eccentricity Eccentricity of magnet center to rotational axis Page 10 Document Feedback Typ 75 Max. offset between defined device center and magnet axis (see Figure 34) Recommended magnet material and temperature drift Min NdFeB (Neodymium Iron Boron) -0.12 SmCo (Samarium Cobalt) -0.035 %/K ams Datasheet [v2-00] 2016-Feb-05 AS5145H/AS5145A/AS5145B − Electrical Characteristics System Specifications TAMB = -40°C to 150°C, VDD5V = 3.0 to 3.6V (3V operation) VDD5V = 4.5 to 5.5V (5V operation) unless otherwise noted. Figure 8: Input Specification Symbol RES Parameter Condition Min Typ Max Unit 12 bit Resolution 0.088 deg Integral non-linearity (optimum) Maximum error with respect to the best line fit. Centered magnet without calibration, TAMB =25 ºC. ± 0.5 deg Integral non-linearity (optimum) Maximum error with respect to the best line fit. Centered magnet without calibration, TAMB = -40°C to 150ºC ± 0.9 deg INL Integral non-linearity Best line fit = (Errmax – Errmin) / 2 Over displacement tolerance with 6mm diameter magnet, without calibration, TAMB = -40°C to 150ºC ± 1.4 deg DNL Differential non-linearity 12-bit, no missing codes ± 0.044 deg INLopt INLtemp 1 sigma, fast mode (MODE = 1) TN Transition noise 1 sigma, slow mode (MODE = 0 or open) Fast mode (Mode = 1); Until status bit OCF = 1 tPwrUp tdelay tdelayINC 0.06 0.03 20 ms Power-up time System propagation delay absolute output : delay of ADC, DSP and absolute interface System propagation delay incremental output AS5145A and AS5145B: delay of ADC, DSP and incremental interface ams Datasheet [v2-00] 2016-Feb-05 deg RMS Slow mode (Mode = 0 or open); Until OCF = 1 80 Fast mode (MODE = 1) 96 Slow mode (MODE = 0 or open) 384 Only fast mode possible 192 μs μs Page 11 Document Feedback AS5145H/AS5145A/AS5145B − Electrical Characteristics Symbol fS fS CLK/SEL Parameter Condition Internal sampling rate for absolute output: Internal sampling rate for absolute output TAMB = 25ºC, slow mode (MODE=0 or open) Min Typ Max 2.48 2.61 2.74 kHz TAMB = -40°C to 150ºC, slow mode (MODE=0 or open) 2.35 2.61 2.87 TAMB = 25ºC, fast mode (MODE = 1) 9.90 10.42 10.94 kHz TAMB = -40°C to 150ºC, fast mode (MODE=1) 9.38 10.42 Max. clock frequency to read out serial data Read-out frequency Unit 11.46 1 MHz Figure 9: Integral and Differential Non-Linearity Example 1023 α 10bit code 1023 Actual curve 2 TN DNL+1LSB 1 0 512 Ideal curve INL 0.35° 512 0 0° 180° 360 ° α [degrees] Integral Non-Linearity (INL) is the maximum deviation between actual position and indicated position. Differential Non-Linearity (DNL) is the maximum deviation of the step length from one position to the next. Transition Noise (TN) is the repeatability of an indicated position. Page 12 Document Feedback ams Datasheet [v2-00] 2016-Feb-05 AS5145H/AS5145A/AS5145B − Timing Characteristics Timing Characteristics TAMB = -40°C to 150 ºC, VDD5V = 3.0 to 3.6V (3V operation) VDD5V = 4.5 to 5.5V (5V operation), unless otherwise noted. Figure 10: Timing Characteristics Symbol Parameter Conditions Min Typ Max Units 100 ns Synchronous Serial Interface (SSI) Data output activated (logic high) Time between falling edge of CSn and data output activated tCLKFE First data shifted to output register Time between falling edge of CSn and first falling edge of CLK 500 ns TCLK/2 Start of data output Rising edge of CLK shifts out one bit at a time 500 ns tDOvalid Data output valid Time between rising edge of CLK and data output valid 413 ns Data output tri-state After the last bit DO changes back to “tri-state” 100 ns tCSn Pulse width of CSn CSn =high; To initiate read-out of next angular position 500 fCLK Read-out frequency Clock frequency to read out serial data >0 tDOactive tDOtristate ns 1 MHz Pulse Width Modulation Output PWM frequency Signal period = 4098μs ±10% at TAMB = -40 to 150ºC 220 244 268 Hz PWMIN Minimum pulse width Position 0d; angle 0 degree 0.90 1 1.10 μs PWMAX Maximum pulse width Position 4098d; angle 359.91 degrees 3686 4096 4506 μs 20 μs fPWM Programming Conditions tPROG Programming time per bit Time to prog. a single fuse bit 10 Refresh time per bit Time to charge the cap after tPROG 1 fLOAD LOAD frequency Data can be loaded at n x 2μs 500 kHz fREAD READ frequency Read the data from the latch 2.5 MHz fWRITE WRITE frequency Write the data to the latch 2.5 MHz tCHARGE ams Datasheet [v2-00] 2016-Feb-05 μs Page 13 Document Feedback AS5145H/AS5145A/AS5145B − Detailed Description Detailed Description The AS5145 is manufactured in a CMOS standard process and uses a spinning current Hall technology for sensing the magnetic field distribution across the surface of the chip. The integrated Hall elements are placed around the center of the device and deliver a voltage representation of the magnetic field at the surface of the IC. Through Sigma-Delta Analog / Digital Conversion and Digital Signal-Processing (DSP) algorithms, the AS5145 provides accurate high-resolution absolute angular position information. For this purpose a Coordinate Rotation Digital Computer (CORDIC) calculates the angle and the magnitude of the Hall array signals. The DSP is also used to provide digital information at the outputs MagINCn and MagDECn that indicate movements of the used magnet towards or away from the device’s surface. A small low cost diametrically magnetized (two-pole) standard magnet provides the angular position information (see Figure 33). The AS5145 senses the orientation of the magnetic field and calculates a 12-bit binary code. This code can be accessed via a Synchronous Serial Interface (SSI). In addition, an absolute angular representation is given by a Pulse Width Modulated signal at pin 12 (PWM). This PWM signal output also allows the generation of a direct proportional analog voltage, by using an external Low-Pass-Filter. The AS5145 is tolerant to magnet misalignment and magnetic stray fields due to differential measurement technique and Hall sensor conditioning circuitry. Figure 11: Typical Arrangement of AS5145 and Magnet Page 14 Document Feedback ams Datasheet [v2-00] 2016-Feb-05 AS5145H/AS5145A/AS5145B − Detailed Description Mode_Index Pin The Mode_Index pin activates or deactivates an internal filter that is used to reduce the analog output noise. Activating the filter (Mode pin = LOW or open) provides a reduced output noise of 0.03º rms. At the same time, the output delay is increased to 384μs. This mode is recommended for high precision, low speed applications. Deactivating the filter (Mode pin = HIGH) reduces the output delay to 96μs and provides an output noise of 0.06º rms. This mode is recommended for higher speed applications. Setup the Mode pin affects the following parameters: Figure 12: Slow and Fast Mode Parameters Slow Mode (Mode = Low or Open) Fast Mode (Mode = High, VDD= 5V) 2.61 kHz (384 μs) 10.42 kHz (96μs) ≤ 0.03º rms ≤ 0.06º rms Output delay 384μs 96μs Maximum speed @ 4096 samples/rev 38 rpm 153 rpm Maximum speed @ 1024 samples/rev 153 rpm 610 rpm Maximum speed @ 256 samples/rev 610 rpm 2441 rpm Maximum speed @ 64 samples/rev 2441 rpm 9766 rpm Parameter Sampling rate Transition noise (1 sigma) Note(s): 1. A change of the Mode during operation is not allowed. The setup must be constant during power up and during operation. ams Datasheet [v2-00] 2016-Feb-05 Page 15 Document Feedback AS5145H/AS5145A/AS5145B − Detailed Description Synchronous Serial Interface (SSI) Figure 13: Synchronous Serial Interface with Absolute Angular Position Data TCLK/2 CSn tCSn tCLK FE 1 CLK D11 DO D10 D9 D8 D7 D6 D5 1 18 8 D4 D3 D2 D1 D0 OCF COF LIN tCLK FE Mag Mag Even INC DEC PAR D11 tDO valid tDO active Angular Position Data Status Bits tDO Tristate If CSn changes to logic low, Data Out (DO) will change from high impedance (tri-state) to logic high and the read-out will be initiated. • After a minimum time tCLK FE, data is latched into the output shift register with the first falling edge of CLK. • Each subsequent rising CLK edge shifts out one bit of data. • The serial word contains 18 bits, the first 12 bits are the angular information D[11:0], the subsequent 6 bits contain system information, about the validity of data such as OCF, COF, LIN, Parity and Magnetic Field status (increase/decrease). • A subsequent measurement is initiated by a “high” pulse at CSn with a minimum duration of t CSn. Data Content D11:D0 absolute angular position data (MSB is clocked out first) OCF (Offset Compensation Finished), logic high indicates the finished Offset Compensation Algorithm COF (CORDIC Overflow), logic high indicates an out of range error in the CORDIC part. When this bit is set, the data at D11:D0 is invalid. The absolute output maintains the last valid angular value. This alarm can be resolved by bringing the magnet within the X-Y-Z tolerance limits. LIN (Linearity Alarm), logic high indicates that the input field generates a critical output linearity. When this bit is set, the data at D11:D0 can still be used, but can contain invalid data. This warning can be resolved by bringing the magnet within the X-Y-Z tolerance limits. Even Parity bit for transmission error detection of bits 1…17 (D11…D0, OCF, COF, LIN, MagINC, MagDEC) Placing the magnet above the chip, angular values increase in clockwise direction by default. Page 16 Document Feedback ams Datasheet [v2-00] 2016-Feb-05 AS5145H/AS5145A/AS5145B − Detailed Description Data D11:D0 is valid, when the status bits have the following configurations: Figure 14: Status Bit Options OCF COF 1 LIN 0 Mag INC Mag DEC 0 0 0 1 1 0 1 1 0 Parity Even checksum of bits 1:15 Note(s): 1. MagInc=MagDec=1 is only recommended in YELLOW mode (see Figure 15) Z-Axis Range Indication (Push Button Feature, Red/Yellow/Green Indicator) The AS5145 provides several options of detecting movement and distance of the magnet in the Z-direction. Signal indicators MagINCn and MagDECn are available both as hardware pins (pins #1 and 2) and as status bits in the serial data stream (see Figure 15). In the default state, the status bits MagINC, MagDec and pins MagINCn, MagDECn have the following function: Figure 15: Magnetic Field Strength Red-Yellow-Green Indicator Hardware Pins Status Bits OTP: Mag CompEn = 1 (Red-Yellow-Green) Mac INC Mag DEC LIN Mac INCn Mag DECn 0 0 0 Off Off No distance change Magnetic input field OK (GREEN range, ~45mT to 75mT) 1 1 0 On Off YELLOW range: magnetic field is ~ 25mT to 45mT or ~75mT to 135mT. The AS5145 can still be operated in this range, but with slightly reduced accuracy. 1 1 1 On On RED range: magnetic field is ~<25mT or >~135mT. It is still possible to operate the AS5145 in the red range, but not recommended. All other combinations n/a n/a Not available Description Note(s): 1. Pin 1 (MagINCn) and pin 2 (MagDECn) are active low via open drain output and require an external pull-up resistor. If the magnetic field is in range, both outputs are turned off. ams Datasheet [v2-00] 2016-Feb-05 Page 17 Document Feedback AS5145H/AS5145A/AS5145B − Detailed Description The two pins can also be combined with a single pull-up resistor. In this case, the signal is high when the magnetic field is in range. It is low in all other cases (see Figure 15). Incremental Mode The AS5145 has an internal interpolator block. This function is used if the input magnetic field is to fast and a code position is missing. In this case an interpolation is done. With the OTP bits OutputMd0 and OutputMd1 a specific mode can be selected. For the available pre-programmed incremental versions (10-bit and 12-bit), these bits are set during test at ams. These settings are permanent and can not be recovered. A change of the incremental mode (WRITE command) during operation could cause problems. A power-on-reset in between is recommended. Figure 16: Incremental Resolution Mode Description Output Md1 Default mode AS5145 function DTEST1_A and DTEST2_B are not used. The Mode_Index pin is used for selection of the decimation rate (low speed/high speed). 0 0 0 1 10-bit Incremental mode (low DNL) 12-bit Incremental mode (high DNL) Sync mode DTEST1_A and DTEST2_B are used as A and B signal. In this mode the Mode_Index Pin is switched from input to output and will be the Index Pin. The decimation rate is set to 64 (fast mode) and cannot be changed from external. In this mode a control signal is switched to DTEST1_A and DTEST2_B. Page 18 Document Feedback Output Md0 Resolution DTest1_A and DTest2_B Pulses 10 256 Index Width 1/3 LSB 1 0 1 1 12 1024 ams Datasheet [v2-00] 2016-Feb-05 AS5145H/AS5145A/AS5145B − Detailed Description Incremental Power-Up Lock Option After power-up, the incremental outputs can optionally be locked or unlocked, depending on the status of the CSn pin: • CSn = low at power-up: CSn has an internal pull-up resistor and must be externally pulled low ( R ext ≤ 5kΩ ). If Csn is low at power-up, the incremental outputs (A, B, Index) will be high until the internal offset compensation is finished. This unique state (A=B=Index = high) can be used as an indicator for the external controller to shorten the waiting time at power-up. Instead of waiting for the specified maximum power up-time (0), the controller can start requesting data from the AS5145 as soon as the state (A=B=Index = high) is cleared. • CSn = high or open at power-up: In this mode, the incremental outputs (A, B, Index) will remain at logic high state, until CSn goes low or a low pulse is applied at CSn. This mode allows intentional disabling of the incremental outputs until, for example the system microcontroller is ready to receive data. Figure 17: Incremental Output ClockWise Programmed Zero Position Counter ClockWise D Test1_A D Test2_B 1 LSB Mode_Index 3 LSB The hysteresis trimming is done at the final test (factory trimming) and set to 4 LSB, related to a 12-bit number. ams Datasheet [v2-00] 2016-Feb-05 Page 19 Document Feedback AS5145H/AS5145A/AS5145B − Detailed Description Incremental Output Hysteresis To avoid flickering incremental outputs at a stationary magnet position, a hysteresis is introduced. In case of a rotational direction change, the incremental outputs have a hysteresis of 4 LSB. Regardless of the programmed incremental resolution, the hysteresis of 4 LSB always corresponds to the highest resolution of 12-bit. In absolute terms, the hysteresis is set to 0.35 degrees for all resolutions. For constant rotational directions, every magnet position change is indicated at the incremental outputs (see Figure 18). For example, if the magnet turns clockwise from position “x+3“to “x+4“, the incremental output would also indicate this position accordingly. A change of the magnet’s rotational direction back to position “x+3“means that the incremental output still remains unchanged for the duration of 4 LSB, until position “x+2“is reached. Following this direction, the incremental outputs will again be updated with every change of the magnet position. Figure 18: Hysteresis Window for Incremental Outputs Incremental Output Indication Hysteresis : 0.35° X +6 X +5 X +4 X +3 X +2 X +1 X X X +1 X +2 X +3 X +4 X +5 X +6 Magnet Position Clockwise Direction Counterclockwise Direction Incremental Output Validity During power on the incremental output is kept stable high until the offset compensation is finished and the CSn is low (internal Pull Up) the first time. In quadrature mode A = B = Index = high indicates an invalid output. If the interpolator recognizes a difference larger than 128 steps between two samples it holds the last valid state. The interpolator synchronizes up again with the next valid difference. This avoids undefined output burst, e.g. if no magnet is present. Page 20 Document Feedback ams Datasheet [v2-00] 2016-Feb-05 AS5145H/AS5145A/AS5145B − Detailed Description Sync Mode This mode is used to synchronize the external electronic with the AS5145. In this mode two signals are provided at the pins DTEST1_A and DTEST2_B. By setting of Md0=1 and Md1=1 in the OTP register, the Sync Mode will be activated. Figure 19: DTest1_A and DTest2_B 400µs (100µs) DTest1_A DTest1_B Every rising edge at DTEST1_A indicates that new data in the device is available. With this signal it is possible to trigger an external customer microcontroller (interrupt) and start the SSI readout. DTEST2_B indicates the phase of available data. Sine/Cosine Mode This mode can be enabled by setting the OTP Factory-bit FS2. If this mode is activated the 16 bit sine and 16 bit cosine digital data of both channels will be switched out. Due to the high resolution of 16 bits of the data stream an accurate calculation can be done externally. In this mode the open drain outputs of DTEST1_A and DTEST2_B are switched to push-pull mode. At pin MagDECn the clock impulse, at pin MagINCn the Enable pulse will be switched out. The pin PWM indicates, which phase of signal is being presented. The mode is not available in the default mode. ams Datasheet [v2-00] 2016-Feb-05 Page 21 Document Feedback AS5145H/AS5145A/AS5145B − Detailed Description Daisy Chain Mode The daisy chain mode allows connection of several AS5145s in series, while still keeping just one digital input for data transfer (see “Data IN” in Figure 20). This mode is accomplished by connecting the data output (DO; pin 9) to the data input (PDIO; pin 8) of the subsequent device. The serial data of all connected devices is read from the DO pin of the first device in the chain. The length of the serial bit stream increases with every connected device, it is n * (18+1) bits: n= number of devices. e.g. 38 bit for two devices, 57 bit for three devices, etc. The last data bit of the first device (Parity) is followed by a dummy bit and the first data bit of the second device (D11), etc. (see Figure 21). Figure 20: Daisy Chain Hardware Configuration AS5145 2nd Device AS5145 1st Device µC Data IN PDIO DO DO PDIO CSn CLK CSn AS5145 last Device DO CLK PDIO CSn CLK CLK CSn Figure 21: Daisy Chain Mode Data Transfer CSn tCLK FE TCLK/2 1 CLK D11 DO tDO active tDO valid D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0 OCF COF LIN Mag Mag Even INC DEC PAR Status Bits Angular Position Data 1st Device Page 22 Document Feedback D 18 8 1 2 3 D11 D10 D9 Angular Position Data 2nd Device ams Datasheet [v2-00] 2016-Feb-05 AS5145H/AS5145A/AS5145B − Detailed Description Pulse Width Modulation (PWM) Output The AS5145 provides a pulse width modulated output (PWM), whose duty cycle is proportional to the measured angle. For angle position 0 to 4094 (EQ1) t ⋅ 4098 ( t on + t off ) on -–1 Position = ------------------------- Examples: 1. An angle position of 180° will generate a pulse width ton = 2049μs and a pause toff of 2049 μs resulting in Position = 2048 after the calculation: 2049 * 4098 / (2049 + 2049) -1 = 2048 2. An angle position of 359.8° will generate a pulse width ton = 4095μs and a pause toff of 3 μs resulting in Position = 4094 after the calculation: 4095 * 4098 / (4095 + 3) -1 = 4094 Exception: 1. An angle position of 359.9° will generate a pulse width ton = 4097μs and a pause toff of 1 μs resulting in Position = 4096 after the calculation: 4097 * 4098 / (4097 + 1) -1 = 4096 The PWM frequency is internally trimmed to an accuracy of ±5% (±10% over full temperature range). This tolerance can be cancelled by measuring the complete duty cycle as shown above. Figure 22: PWM Output Signal Angle PWMIN 0 deg (Pos 0) 1µs 4098µs PWMAX 359.91 deg (Pos 4095) 4097µs 1/fPWM ams Datasheet [v2-00] 2016-Feb-05 Page 23 Document Feedback AS5145H/AS5145A/AS5145B − Detailed Description Changing the PWM Frequency The PWM frequency of the AS5145 can be divided by two by setting a bit (PWMhalfEN) in the OTP register (see Programming the AS5145). With PWMhalfEN = 0 the PWM timing is as shown in Figure 23: Figure 23: PWM Signal Parameters (Default Mode) Symbol Parameter Typ Unit Note fPWM PWM frequency 244 Hz PWMIN MIN pulse width 1 μs • Position 0d • Angle 0 deg PWMAX MAX pulse width 4097 μs • Position 4095d • Angle 359.91 deg Signal period: 4097μs When PWMhalfEN = 1, the PWM timing is as shown in Figure 24: Figure 24: PWM Signal Parameters with Half Frequency (OTP Option) Symbol Parameter Typ Unit fPWM PWM frequency 122 Hz PWMIN MIN pulse width 2 μs • Position 0d • Angle 0 deg PWMAX MAX pulse width 8194 μs • Position 4095d • Angle 359.91 deg Page 24 Document Feedback Note Signal period: 8194μs ams Datasheet [v2-00] 2016-Feb-05 AS5145H/AS5145A/AS5145B − Detailed Description Analog Output An analog output can be generated by averaging the PWM signal, using an external active or passive low pass filter. The analog output voltage is proportional to the angle: 0º= 0V; 360º = VDD5V. Using this method, the AS5145 can be used as direct replacement of potentiometers. Figure 25: Simple 2nd Order Passive RC Low Pass Filter Pin12 R2 R1 analog out PWM VDD C1 C2 0V Pin7 0º 360º VSS Figure 25 shows an example of a simple passive low pass filter to generate the analog output. (EQ2) R1,R2 ≥ 10k Ω C1,C2 ≥ 2.2μF / 6V R1 should be greater than or equal to 4k7 to avoid loading of the PWM output. Larger values of Rx and Cx will provide better filtering and less ripple, but will also slow down the response time. ams Datasheet [v2-00] 2016-Feb-05 Page 25 Document Feedback AS5145H/AS5145A/AS5145B − Application Information Application Information The benefits of AS5145 are as follows: • Complete system-on-chip • Flexible system solution provides absolute and PWM outputs simultaneously • Ideal for applications in harsh environments due to contactless position sensing • No calibration required • No temperature compensation necessary Programming the AS5145 After power-on, programming the AS5145 is enabled with the rising edge of CSn with PDIO = high and CLK = low. The AS5145 programming is a one-time-programming (OTP) method, based on poly silicon fuses. The advantage of this method is that a programming voltage of only 3.3V to 3.6V is required for programming (either with 3.3V or 5V supply). The OTP consists of 52 bits, of which 21 bits are available for user programming. The remaining 31 bits contain factory settings and a unique chip identifier (Chip-ID). A single OTP cell can be programmed only once. Per default, the cell is “0”; a programmed cell will contain a “1”. While it is not possible to reset a programmed bit from “1” to “0”, multiple OTP writes are possible, as long as only unprogrammed “0”-bits are programmed to “1”. Independent of the OTP programming, it is possible to overwrite the OTP register temporarily with an OTP write command at any time. This setting will be cleared and overwritten with the hard programmed OTP settings at each power-up sequence or by a LOAD operation. Use application note AN514X_10 to get more information about the programming options. The OTP memory can be accessed in the following ways: • Load Operation: The Load operation reads the OTP fuses and loads the contents into the OTP register. A Load operation is automatically executed after each power-on-reset. • Write Operation: The Write operation allows a temporary modification of the OTP register. It does not program the OTP. This operation can be invoked multiple times and will remain set while the chip is supplied with power and while the OTP register is not modified with another Write or Load operation. • Read Operation: The Read operation reads the contents of the OTP register, for example to verify a Write command or to read the OTP memory after a Load command. • Program Operation: The Program operation writes the contents of the OTP register permanently into the OTP ROM. Page 26 Document Feedback ams Datasheet [v2-00] 2016-Feb-05 AS5145H/AS5145A/AS5145B − Application Information • Analog Readback Operation: The Analog Readback operation allows a quantifiable verification of the programming. For each programmed or unprogrammed bit, there is a representative analog value (in essence, a resistor value) that is read to verify whether a bit has been successfully programmed or not. Zero Position Programming Zero position programming is an OTP option that simplifies assembly of a system, as the magnet does not need to be manually adjusted to the mechanical zero position. Once the assembly is completed, the mechanical and electrical zero positions can be matched by software. Any position within a full turn can be defined as the permanent new zero position. For zero position programming, the magnet is turned to the mechanical zero position (e.g. the “off”-position of a rotary switch) and the actual angular value is read. This value is written into the OTP register bits Z35:Z46 (see Figure 28). Note(s): The zero position value can also be modified before programming, e.g. to program an electrical zero position that is 180º (half turn) from the mechanical zero position, just add 2048 to the value read at the mechanical zero position and program the new value into the OTP register. ams Datasheet [v2-00] 2016-Feb-05 Page 27 Document Feedback AS5145H/AS5145A/AS5145B − Application Information OTP Memory Assignment Symbol Function mbit1 Factory Bit 1 51 PWMhalfEN_Index width PMW frequency Index pulse width 50 MagCompEn Alarm mode (programmed by ams to 1) 49 pwmDIS Disable PWM 48 Output Md0 47 Output Md1 46 Z0 : : 35 Z11 34 CCW 33 RA0 : : 29 RA4 28 FS 0 27 FS 1 26 FS 2 25 FS 3 24 FS 4 23 FS 5 : : 20 FS 8 19 FS 9 18 FS 10 Default, 10-bit inc, 12-bit inc Sync mode 12-bit Zero Position Direction Redundancy Address Factory Bit Page 28 Document Feedback Factory Section Bit Customer Section Figure 26: OTP Bit Assignment ams Datasheet [v2-00] 2016-Feb-05 AS5145H/AS5145A/AS5145B − Application Information Symbol 17 ChipID0 16 ChipID1 : : 0 ChipID17 Function ID Section Bit 18-bit Chip ID mbit0 Factory Bit 0 User Selectable Settings The AS5145 allows programming of the following user selectable options: • PWMhalfEN_Indexwidth: Setting this bit, the PWM pulse will be divided by 2, in case of quadrature incremental mode A/B/Index setting of index impulse width from 1 LSB to 3LSB • Output Md0: Setting this bit enables sync- or 10-bit incremental mode (see Figure 16). • Output Md1: Setting this bit enables sync- or 12-bit incremental mode (see Figure 16). • Z [11:0]: Programmable Zero / Index Position • CCW: Counter Clockwise Bit ccw=0 – angular value increases in clockwise direction ccw=1 – angular value increases in counterclockwise direction • RA [4:0]: Redundant Address: an OTP bit location addressed by this address is always set to “1” independent of the corresponding original OTP bit setting OTP Default Setting The AS5145 can also be operated without programming. The default, un-programmed setting is: • Output Md0, Output MD1: 00= Default mode • Z0 to Z11: 00 = no programmed zero position • CCW: 0 = clockwise operation • RA4 to RA0:0 = no OTP bit is selected • MagCompEN: 1 = The green/yellow Mode is enabled ams Datasheet [v2-00] 2016-Feb-05 Page 29 Document Feedback AS5145H/AS5145A/AS5145B − Application Information Redundancy For a better programming reliability a redundancy is implemented. In case when the programming of one bit failed this function can be used. With an address RA(4:0) one bit can be selected and programmed. 0 0 00001 1 0 0 00010 0 1 00011 0 00100 Z0 Z1 Z2 Z3 Z4 Z5 Z6 Z7 Z8 Z9 Z10 Z11 CCW pwmDIS 0 Output Md1 MagCompEN 00000 Output Md0 Address PWMhalfEN_Indexwidth Figure 27: Redundancy Addressing 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00101 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 00110 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 00111 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 01000 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 01001 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 01010 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 01011 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 01100 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 01101 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 01110 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 01111 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 10000 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 10001 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 10010 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 10101 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Page 30 Document Feedback ams Datasheet [v2-00] 2016-Feb-05 AS5145H/AS5145A/AS5145B − Application Information Redundant Programming Option In addition to the regular programming, a redundant programming option is available. This option allows that one selectable OTP bit can be set to “1” (programmed state) by writing the location of that bit into a 5-bit address decoder. This address can be stored in bits RA4...RA0 in the OTP user settings. Example: setting RA4…0 to “00001” will select bit 51 = PWhalfEN_Indexwidth, “00010” selects bit 50 = MagCompEN, “10010” selects bit 34 =CCW, etc. OTP Register Entry and Exit Condition For timing options, refer to Programming the AS5145. Figure 28: OTP Access Timing Diagram OTP Access Setup Condition CSn PDIO CLK Operation Mode Selection Exit Condition To avoid accidental modification of the OTP during normal operation, each OTP access (Load, Write, Read, Program) requires a defined entry and exit procedure, using the CSn, PDIO and CLK signals as shown in Figure 28. ams Datasheet [v2-00] 2016-Feb-05 Page 31 Document Feedback AS5145H/AS5145A/AS5145B − Application Information Figure 29: OTP Programming Connection AS5145 Demoboard 1 MagINCn 2 MagDECn 3 VDD5V 16 VDD3V3 15 6 7 8 10n NC Mode_ Index 3V3 NC 14 13 NC DTest 1_A 4 DTest2_B 5 PWM CSn VSS CLK PDIO DO AS 5 1 4 5 USB For programming, k eep these 6 wires as short as possible! max. length = 2 inches (5cm) IC 1 7 6 5 4 3 2 1 12 11 10 9 2.2µF 22k PROG CSN DO CLK 5 VUSB VDD3V3 VSS µC GND connect to USB interface on PC 3 VPROG 2 + 1 10µF VSS GND 3.3 … 4. 6 V only required for OTP programming Cap only required for OTP programming Alignment Mode The alignment mode simplifies centering the magnet over the center of the chip to gain maximum accuracy. Alignment mode can be enabled with the falling edge of CSn while PDIO = logic high (see Figure 30). The Data bits D11-D0 of the SSI change to a 12-bit displacement amplitude output. A high value indicates large X or Y displacement, but also higher absolute magnetic field strength. The magnet is properly aligned, when the difference between highest and lowest value over one full turn is at a minimum. Under normal conditions, a properly aligned magnet will result in a reading of less than 128 over a full turn. The MagINCn and MagDECn indicators will be = 1 when the alignment mode reading is < 128. At the same time, both hardware pins MagINCn (#1) and MagDECn (#2) will be pulled to VSS. A properly aligned magnet will therefore produce a MagINCn = MagDECn = 1 signal throughout a full 360º turn of the magnet. Stronger magnets or short gaps between magnet and IC will show values larger than 128. These magnets are still properly aligned as long as the difference between highest and lowest value over one full turn is at a minimum. The Alignment mode can be reset to normal operation by a power-on-reset (disconnect / re-connect power supply) or by a falling edge on CSn with PDIO = low. Page 32 Document Feedback ams Datasheet [v2-00] 2016-Feb-05 AS5145H/AS5145A/AS5145B − Application Information Figure 30: Enabling the Alignment Mode PDIO CSn 2µs min. AlignMode enable Read-out via SSI exit AlignMode Read-out via SSI 2µs min. Figure 31: Exiting Alignment Mode PDIO CSn ams Datasheet [v2-00] 2016-Feb-05 Page 33 Document Feedback AS5145H/AS5145A/AS5145B − Application Information 3.3V / 5V Operation The AS5145 operates either at 3.3V ±10% or at 5V ±10%. This is made possible by an internal 3.3V Low-Dropout (LDO) Voltage regulator. The internal supply voltage is always taken from the output of the LDO, meaning that the internal blocks are always operating at 3.3V. For 3.3V operation, the LDO must be bypassed by connecting VDD3V3 with VDD5V (see Figure 32). For 5V operation, the 5V supply is connected to pin VDD5V, while VDD3V3 (LDO output) must be buffered by a 1μF to 10μF capacitor, which is supposed to be placed close to the supply pin (see Figure 32) with recommended 2.2μF). Note(s): The VDD3V3 output is intended for internal use only It must not be loaded with an external load. The output voltage of the digital interface I/O’s corresponds to the voltage at pin VDD5V, as the I/O buffers are supplied from this pin. Figure 32: Connections for 5V / 3.3V Supply Voltages 5V Operation 3.3V Operation 2.2 ... 10µF VDD3V3 VDD3V3 100nF VDD5V 100nF LDO Internal VDD VDD5V LDO Internal VDD DO DO PWM 4.5 - 5.5V VSS Page 34 Document Feedback I N T E R F A C E CLK CSn + - - + 3.0 - 3.6V PDIO VSS I N T E R F A C E PWM CLK CSn PDIO ams Datasheet [v2-00] 2016-Feb-05 AS5145H/AS5145A/AS5145B − Application Information A buffer capacitor of 100nF is recommended in both cases close to pin VDD 5V. Note that pin VDD 3V3 must always be buffered by a capacitor. It must not be left floating, as this may cause an instable internal 3.3V supply voltage which can lead to larger than normal jitter of the measured angle. Selecting Proper Magnet Typically the magnet is 6mm in diameter and 2.5mm in height. Magnetic materials such as rare earth AlNiCo/SmCo5 or NdFeB are recommended. The magnetic field strength perpendicular to the die surface has to be in the range of ±45mT to ±75mT (peak). The magnet’s field strength is verified using a gauss-meter. The magnetic field Bv at a given distance, along a concentric circle with a radius of 1.1mm (R1) is in the range of ±45mT to ±75mT(see Figure 33). Figure 33: Typical Magnet (6x3mm) and Magnetic Field Distribution typ. 6mm diameter N S Magnet axis R1 Magnet axis Vertical field component R1 concentric circle; radius 1.1mm Vertical field component Bv (45…75mT) 0 360 360 ams Datasheet [v2-00] 2016-Feb-05 Page 35 Document Feedback AS5145H/AS5145A/AS5145B − Application Information Physical Placement of the Magnet The best linearity can be achieved by placing the center of the magnet exactly over the defined center of the chip as shown in the drawing below: Figure 34: Defined Chip Center and Magnet Displacement Radius 3.9mm 3.9mm 2.4325mm 1 Defined center 2.4325mm Rd Area of recommended maximum magnet misalignment Magnet Placement The magnet’s center axis must be aligned within a displacement radius Rd of 0.25mm from the defined center of the IC. The magnet can be placed below or above the device. The distance can be chosen such that the magnetic field on the die surface is within the specified limits (see Figure 34). The typical distance “z” between the magnet and the package surface is 0.5mm to 1.5mm, provided the use of the recommended magnet material and dimensions (6mm x 3mm). Larger distances are possible, as long as the required magnetic field strength stays within the defined limits. A magnetic field outside the specified range still can be detected by the chip. But the out-of-range condition will be indicated by MagINCn (pin 1) and MagDECn (pin 2), (see Figure 4). Page 36 Document Feedback ams Datasheet [v2-00] 2016-Feb-05 AS5145H/AS5145A/AS5145B − Application Information Failure Diagnostics The AS5145 also offers several diagnostic and failure detection features: Magnetic Field Strength Diagnosis By software: the MagINC and MagDEC status bits will both be high when the magnetic field is out of range. By hardware: Pins #1 (MagINCn) and #2 (MagDECn) are open-drain outputs and will both be turned on (= low with external pull-up resistor) when the magnetic field is out of range. If only one of the outputs are low, the magnet is either moving towards the chip (MagINCn) or away from the chip (MagDECn). Power Supply Failure Detection By software: If the power supply to the AS5145 is interrupted, the digital data read by the SSI will be all “0”s. Data is only valid, when bit OCF is high, hence a data stream with all “0”s is invalid. To ensure adequate low levels in the failure case, a pull-down resistor (~10kΩ) must be added between pin DIO and VSS at the receiving side. By hardware: The MagINCn and MagDECn pins are open drain outputs and require external pull-up resistors. In normal operation, these pins are high ohmic and the outputs are high (see Figure 15). In a failure case, either when the magnetic field is out of range of the power supply is missing, these outputs will become low. To ensure adequate low levels in case of a broken power supply to the AS5145, the pull-up resistors (~10kΩ) from each pin must be connected to the positive supply at pin 16 (VDD5V). By hardware: PWM output: The PWM output is a constant stream of pulses with 1kHz repetition frequency. In case of power loss, these pulses are missing. ams Datasheet [v2-00] 2016-Feb-05 Page 37 Document Feedback AS5145H/AS5145A/AS5145B − Application Information Angular Output Tolerances Accuracy Accuracy is defined as the error between measured angle and actual angle. It is influenced by several factors: • The non-linearity of the analog-digital converters • Internal gain and mismatch errors • Non-linearity due to misalignment of the magnet As a sum of all these errors, the accuracy with centered magnet = (Errmax – Errmin)/2 is specified as better than ±0.5 degrees @ 25ºC (see Figure 36). Misalignment of the magnet further reduces the accuracy. Figure 35 shows an example of a 3D-graph displaying non-linearity over XY-misalignment. The center of the square XY-area corresponds to a centered magnet (see dot in the center of the graph). The X- and Y- axis extends to a misalignment of ±1mm in both directions. The total misalignment area of the graph covers a square of 2x2mm (79x79mil) with a step size of 100μm. For each misalignment step, the measurement as shown in Figure 36 is repeated and the accuracy (Errmax – Errmin)/2 (e.g. 0.25º in Figure 36) is entered as the Z-axis in the 3D-graph. Figure 35: Example of Linearity Error Over XY Misalignment 6 5 4 ° 3 800 500 2 200 1 -100 -700 -1000 -1000 -800 -400 -600 -200 0 200 600 y Page 38 Document Feedback x -400 400 1000 800 0 ams Datasheet [v2-00] 2016-Feb-05 AS5145H/AS5145A/AS5145B − Application Information The maximum non-linearity error on this example is better than ±1 degree (inner circle) over a misalignment radius of ~0.7mm. For volume production, the placement tolerance of the IC within the package (±0.235mm) must also be taken into account. The total nonlinearity error over process tolerances, temperature and a misalignment circle radius of 0.25mm is specified better than ±1.4 degrees. The magnet used for this measurement was a cylindrical NdFeB (Bomatec® BMN-35H) magnet with 6mm diameter and 2.5mm in height. Figure 36: Example of Linearity Error Over 360º 0.5 0.4 0.3 0.2 transition noise 0.1 Err max 0 -0.1 1 55 109 163 217 271 325 379 433 487 541 595 649 703 757 811 865 919 973 Err min -0.2 -0.3 -0.4 -0.5 Transition Noise Transition noise is defined as the jitter in the transition between two steps. Due to the nature of the measurement principle (Hall sensors + Preamplifier + ADC), there is always a certain degree of noise involved. This transition noise voltage results in an angular transition noise at the outputs. It is specified as 0.06 degrees rms (1 sigma)x1 in fast mode (pin MODE = high) and 0.03 degrees rms (1 sigma)x1 in slow mode (pin MODE = low or open). This is the repeatability of an indicated angle at a given mechanical position. The transition noise has different implications on the type of output that is used: • Absolute Output; SSI Interface: The transition noise of the absolute output can be reduced by the user by implementing averaging of readings. An averaging of 4 readings will reduce the transition noise by 6dB or 50%, e.g. from 0.03ºrms to 0.015ºrms (1 sigma) in slow mode. ams Datasheet [v2-00] 2016-Feb-05 Page 39 Document Feedback AS5145H/AS5145A/AS5145B − Application Information • PWM Interface: If the PWM interface is used as an analog output by adding a low pass filter, the transition noise can be reduced by lowering the cutoff frequency of the filter. If the PWM interface is used as a digital interface with a counter at the receiving side, the transition noise can be further reduced by averaging of readings. • Incremental Mode: In incremental mode, the transition noise influences the period, width and phase shift of the output signals A, B and Index. However, the algorithm used to generate the incremental outputs guarantees no missing or additional pulses even at high speeds (up to 15,000 rpm and higher). Note(s): Statistically, 1 sigma represents 68.27% of readings and 3 sigma represents 99.73% of readings. High Speed Operation • Sampling Rate: The AS5145 samples the angular value at a rate of 2.61k (slow mode) or 10.42k (fast mode, selectable by pin MODE) samples per second. Consequently, the absolute outputs are updated each 384μs (96μs in fast mode). At a stationary position of the magnet, the sampling rate creates no additional error. • Absolute Mode: At a sampling rate of 2.6kHz/10.4kHz, the number of samples (n) per turn for a magnet rotating at high speed can be calculated by (EQ3) nslowmode = 60 ---------------------------------rpm ⋅ ( 384 )μs (EQ4) nfastmode = 60 -------------------------rmp ⋅ 96μs The upper speed limit in slow mode is ~6,000 rpm and ~30,000 rpm in fast mode. The only restriction at high speed is that there will be fewer samples per revolution as the speed increases (see Figure 12). Regardless of the rotational speed, the absolute angular value is always sampled at the highest resolution of 12-bit. • Incremental Mode: Incremental encoders are usually required to produce no missing pulses up to several thousand rpm. Therefore, the AS5145 has a built-in interpolator, which ensures that there are no missing pulses at the incremental outputs for rotational speeds of up to 15,000 rpm, even at the highest resolution of 12 bits (4096 pulses per revolution). Page 40 Document Feedback ams Datasheet [v2-00] 2016-Feb-05 AS5145H/AS5145A/AS5145B − Application Information Propagation Delays The propagation delay is the delay between the time that the sample is taken until it is converted and available as angular data. This delay is 96μs in fast mode and 384μs in slow mode. Using the SSI interface for absolute data transmission, an additional delay must be considered, caused by the asynchronous sampling (0 … 1/fsample) and the time it takes the external control unit to read and process the angular data from the chip (maximum clock rate = 1MHz, number of bits per reading = 18). Angular Error Caused by Propagation Delay A rotating magnet will cause an angular error caused by the output propagation delay. This error increases linearly with speed: (EQ5) e sampling = rpm * 6 * prop.delay where: esampling = angular error [º] rpm = rotating speed [rpm] prop.delay = propagation delay [seconds] Note(s): Since the propagation delay is known, it can be automatically compensated by the control unit processing the data from the AS5145. Internal Timing Tolerance The AS5145 does not require an external ceramic resonator or quartz. All internal clock timings for the AS5145 are generated by an on-chip RC oscillator. This oscillator is factory trimmed to ±5% accuracy at room temperature (±10% over full temperature range). This tolerance influences the ADC sampling rate and the pulse width of the PWM output: • Absolute output; SSI interface: A new angular value is updated every 96μs (typ) in fast mode and every 384μs (typ) in slow mode. • PWM output: A new angular value is updated every 384μs (typ). The PWM pulse timings T on and Toff also have the same tolerance as the internal oscillator. If only the PWM pulse width Ton is used to measure the angle, the resulting value also has this timing tolerance. However, this tolerance can be cancelled by measuring both Ton and T off and calculating the angle from the duty cycle (see Pulse Width Modulation (PWM) Output) (EQ6) ams Datasheet [v2-00] 2016-Feb-05 t ⋅ 4097 ( t on + t off ) on -–1 Position = ------------------------- Page 41 Document Feedback AS5145H/AS5145A/AS5145B − Application Information Temperature Magnetic Temperature Coefficient. One of the major benefits of the AS5145 compared to linear Hall sensors is that it is much less sensitive to temperature. While linear Hall sensors require a compensation of the magnet’s temperature coefficients, the AS5145 automatically compensates for the varying magnetic field strength over temperature. The magnet’s temperature drift does not need to be considered, as the AS5145 operates with magnetic field strengths from ±45mT to ±75mT. Example: A NdFeB magnet has a field strength of 75mT @ –40ºC and a temperature coefficient of -0.12% per Kelvin. The temperature change is from -40ºC to 125ºC = 165K.The magnetic field change is: 165 x -0.12% = -19.8%, which corresponds to 75mT at -40ºC and 60mT at 125ºC. The AS5145 can compensate for this temperature related field strength change automatically, no user adjustment is required. Accuracy Over Temperature The influence of temperature in the absolute accuracy is very low. While the accuracy is less than or equal to ±0.5º at room temperature, it can increase to less than or equal to ±0.9º due to increasing noise at high temperatures. Timing Tolerance Over Temperature. The internal RC oscillator is factory trimmed to ±5%. Over temperature, this tolerance can increase to ±10%. Generally, the timing tolerance has no influence in the accuracy or resolution of the system, as it is used mainly for internal clock generation. The only concern to the user is the width of the PWM output pulse, which relates directly to the timing tolerance of the internal oscillator. This influence however can be cancelled by measuring the complete PWM duty cycle instead of just the PWM pulse. Page 42 Document Feedback ams Datasheet [v2-00] 2016-Feb-05 AS5145H/AS5145A/AS5145B − Application Information Differences Between AS5145H, AS5145A and AS5145B Figure 37: Functional Differences Function AS5145H AS5145A AS5145B Filtering mode Selectable by customer via Mode pin (see Figure 12) Mode_Index pin Input. Must be set hard wired on PCB Output Output Incremental mode setting Default disabled. Can be enabled by customer via programming Pre-defined to 2x256 ppr low-jitter (10-bit) Pre-defined to 2x1024 ppr (12-bit) Resolution absolute angle output (PWM and SSI) ams Datasheet [v2-00] 2016-Feb-05 Pre-defined to Fast mode 12-Bit angle Page 43 Document Feedback AS5145H/AS5145A/AS5145B − Package Drawings & Markings Package Drawings & Markings The device is available in SSOP 16 (5.3mm x 6.2mm). Figure 38: Package Drawings and Dimensions Symbol Min Nom Max A A1 A2 b c D E E1 e L L1 L2 R Q N 1.73 0.05 1.68 0.22 0.09 5.90 7.40 5.00 0.55 0.09 0º 1.86 0.13 1.73 0.315 0.17 6.20 7.80 5.30 0.65 BSC 0.75 1.25 REF 0.25 BSC 4º 16 1.99 0.21 1.78 0.38 0.25 6.50 8.20 5.60 0.95 8º RoHS Green Note(s): 1. Dimensions and tolerancing conform to ASME Y14.5M-1994. 2. All dimensions are in millimeters. Angles are in degrees. Figure 39: Package Code: YYWWMZZ YY WW M ZZ @ Manufacturing year Manufacturing week Plant identifier Assembly traceability code Sublot identifier Page 44 Document Feedback ams Datasheet [v2-00] 2016-Feb-05 AS5145H/AS5145A/AS5145B − Package Drawings & Markings Figure 40: Vertical Cross Section of SSOP-16 Note(s): 1. All dimensions in mm. ams Datasheet [v2-00] 2016-Feb-05 Page 45 Document Feedback AS5145H/AS5145A/AS5145B − Package Drawings & Markings Recommended PCB Footprint Figure 41: PCB Footprint Recommended Footprint Data Symbol mm A B C D E Page 46 Document Feedback 9.02 6.16 0.46 0.65 5.01 ams Datasheet [v2-00] 2016-Feb-05 AS5145H/AS5145A/AS5145B − Ordering & Contact Information Ordering & Contact Information The devices are available as the standard products shown in Figure 42. Figure 42: Ordering Information Ordering Code AS5145H-HSST AS5145H-HSSM AS5145A-HSST AS5145A-HSSM AS5145B-HSST AS5145B-HSSM Description Package Delivery Quantity 2000 pcs/reel 12-Bit Programmable Magnetic Rotary Encoder Pre-programmed 10-bit incremental Delivery Form Tape & Reel 500 pcs/reel SSOP 16 (5.3mm x 6.2mm) Pre-programmed 12-bit incremental 2000 pcs/reel Tape & Reel 500 pcs/reel 2000 pcs/reel Tape & Reel 500 pcs/reel Buy our products or get free samples online at: www.ams.com/ICdirect Technical Support is available at: www.ams.com/Technical-Support Provide feedback about this document at: www.ams.com/Document-Feedback For further information and requests, e-mail us at: [email protected] For sales offices, distributors and representatives, please visit: www.ams.com/contact Headquarters ams AG Tobelbaderstrasse 30 8141 Premstaetten Austria, Europe Tel: +43 (0) 3136 500 0 Website: www.ams.com ams Datasheet [v2-00] 2016-Feb-05 Page 47 Document Feedback AS5145H/AS5145A/AS5145B − RoHS Compliant & ams Green Statement RoHS Compliant & ams Green Statement RoHS: The term RoHS compliant means that ams AG products fully comply with current RoHS directives. Our semiconductor products do not contain any chemicals for all 6 substance categories, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, RoHS compliant products are suitable for use in specified lead-free processes. ams Green (RoHS compliant and no Sb/Br): ams Green defines that in addition to RoHS compliance, our products are free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material). Important Information: The information provided in this statement represents ams AG knowledge and belief as of the date that it is provided. ams AG bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. ams AG has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. ams AG and ams AG suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. Page 48 Document Feedback ams Datasheet [v2-00] 2016-Feb-05 AS5145H/AS5145A/AS5145B − Copyrights & Disclaimer Copyrights & Disclaimer Copyright ams AG, Tobelbader Strasse 30, 8141 Premstaetten, Austria-Europe. Trademarks Registered. All rights reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner. Devices sold by ams AG are covered by the warranty and patent indemnification provisions appearing in its General Terms of Trade. ams AG makes no warranty, express, statutory, implied, or by description regarding the information set forth herein. ams AG reserves the right to change specifications and prices at any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with ams AG for current information. This product is intended for use in commercial applications. Applications requiring extended temperature range, unusual environmental requirements, or high reliability applications, such as military, medical life-support or life-sustaining equipment are specifically not recommended without additional processing by ams AG for each application. This product is provided by ams AG “AS IS” and any express or implied warranties, including, but not limited to the implied warranties of merchantability and fitness for a particular purpose are disclaimed. ams AG shall not be liable to recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use, interruption of business or indirect, special, incidental or consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of ams AG rendering of technical or other services. ams Datasheet [v2-00] 2016-Feb-05 Page 49 Document Feedback AS5145H/AS5145A/AS5145B − Document Status Document Status Document Status Product Preview Preliminary Datasheet Datasheet Datasheet (discontinued) Page 50 Document Feedback Product Status Definition Pre-Development Information in this datasheet is based on product ideas in the planning phase of development. All specifications are design goals without any warranty and are subject to change without notice Pre-Production Information in this datasheet is based on products in the design, validation or qualification phase of development. The performance and parameters shown in this document are preliminary without any warranty and are subject to change without notice Production Information in this datasheet is based on products in ramp-up to full production or full production which conform to specifications in accordance with the terms of ams AG standard warranty as given in the General Terms of Trade Discontinued Information in this datasheet is based on products which conform to specifications in accordance with the terms of ams AG standard warranty as given in the General Terms of Trade, but these products have been superseded and should not be used for new designs ams Datasheet [v2-00] 2016-Feb-05 AS5145H/AS5145A/AS5145B − Revision Information Revision Information Changes from 1.17 (2013-Jul-04) to current revision 2-00 (2016-Feb-05) Page Content was updated to the latest ams design Added benefits to Figure 1 1 Updated Figure 6 and text above it 7 Updated text above Figure 7 10 Updated text above Figure 8 11 Updated text above Figure 10 13 Updated Figure 39 44 Updated Figure 42 47 Note(s): 1. Page and figure numbers for the previous version may differ from page and figure numbers in the current revision. 2. Correction of typographical errors is not explicitly mentioned. ams Datasheet [v2-00] 2016-Feb-05 Page 51 Document Feedback AS5145H/AS5145A/AS5145B − Content Guide Content Guide Page 52 Document Feedback 1 1 2 2 General Description Key Benefits & Features Applications Block Diagram 3 3 Pin Assignment Pin Description 6 Absolute Maximum Ratings 7 10 11 Electrical Characteristics Magnetic Input Specification System Specifications 13 Timing Characteristics 14 15 16 18 21 21 22 23 24 25 Detailed Description Mode_Index Pin Synchronous Serial Interface (SSI) Incremental Mode Sync Mode Sin/Cosine Mode Daisy Chain Mode Pulse Width Modulation (PWM) Output Changing the PWM Frequency Analog Output 26 26 27 28 29 29 30 31 31 32 34 35 36 36 37 37 37 38 38 39 40 41 41 42 42 43 Application Information Programming the AS5145 Zero Position Programming OTP Memory Assignment User Selectable Settings OTP Default Setting Redundancy Redundant Programming Option OTP Register Entry and Exit Condition Alignment Mode 3.3V / 5V Operation Selecting Proper Magnet Physical Placement of the Magnet Magnet Placement Failure Diagnostics Magnetic Field Strength Diagnosis Power Supply Failure Detection Angular Output Tolerances Accuracy Transition Noise High Speed Operation Propagation Delays Internal Timing Tolerance Temperature Accuracy Over Temperature Differences Between AS5145H, AS5145A and AS5145B ams Datasheet [v2-00] 2016-Feb-05 AS5145H/AS5145A/AS5145B − Content Guide ams Datasheet [v2-00] 2016-Feb-05 44 46 Package Drawings & Markings Recommended PCB Footprint 47 48 49 50 51 Ordering & Contact Information RoHS Compliant & ams Green Statement Copyrights & Disclaimer Document Status Revision Information Page 53 Document Feedback