AS5140H 10-Bit 360º Programmable Magnetic Rotary Encoder For High Ambient Temperatures General Description The AS5140H is a contactless magnetic rotary encoder for accurate angular measurement over a full turn of 360º and over an extended ambient temperature range of -40ºC to 150ºC. 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 may be placed above or below the IC. The absolute angle measurement provides instant indication of the magnet’s angular position with a resolution of 0.35º = 1024 positions per revolution. This digital data is available as a serial bit stream and as a PWM signal. Furthermore, a user-programmable incremental output is available. An internal voltage regulator allows the AS5140H to operate at either 3.3V or 5V supplies. The AS5140H is pin-compatible to the AS5040; however it uses low-voltage OTP programming cells with additional programming options. Ordering Information and Content Guide appear at end of datasheet. Key Benefits & Features The benefits and features of AS5140H, 10-Bit 360º Programmable Magnetic Rotary Encoder For High Ambient Temperatures are listed below: Figure 1: Added Value of Using AS5140H Benefits Features No mechanical wear Contactless high resolution rotational position encoding over a full turn of 360º High resolution absolute position sensing Two digital 10-bit absolute outputs: Serial interface and Pulse width modulated (PWM) output Easy to use for motor control Three incremental output modes: Quadrature A/B and Index output signal, Step / Direction and Index output signal, 3-phase commutation for brushless DC motors Adjustable zero position User programmable zero / index position ams Datasheet [v1-08] 2015-Jan-16 Page 1 Document Feedback AS5140H − General Description Benefits Features Tolerant to magnet misalignment Failure detection mode for magnet placement monitoring and loss of power supply Usable for high speed applications Rotational speeds up to 10.000 rpm Tolerant to airgap variations Pushbutton functionality detects movement of magnet in Z-axis Supports daisy chain application Serial read-out of multiple interconnected AS5140H devices using Daisy Chain mode Fitting to automotive applications Fully automotive qualified to AEC-Q100, grade 0 Operates up to 150°C ambient temperature Wide ambient temperature range: -40ºC to 150ºC Applications The AS5140H is an ideal solution for automotive applications like engine compartment sensors, transmission gearbox encoder, throttle valve position control and for industrial applications like rotary sensors in high temperature environment. Block Diagram The functional blocks of this device for reference are shown below: Figure 2: AS5140H Block Diagram 9''99 9''9 0DJ,1&Q 0DJ'(&Q LDO 3.3V PWM Interface 6LQ Hall Array & Frontend Amplifier AS5140H &RV 3:0B/6% $QJ DSP 0DJ Absolute Interface (SSI) '2 &6Q &/. OTP Register Programming Parameters Incremental Interface $B/6%B8 %B'LUB9 ,QGH[B: 3URJ Page 2 Document Feedback ams Datasheet [v1-08] 2015-Jan-16 AS5140H − Pin Assignment Pin Assignment Figure 3: Pin Diagram (Top View) 9''9 0DJ'(&Q 9''9 $B/6%B8 1& %B'LUB9 1& 3:0B/6% &6Q AS5140H 0DJ,1&Q 1& ,QGH[B: 966 &/. 3URJ '2 Pin Description The following figure 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 Number Pin Name 1 MagINCn Magnet Field Magnitude Increase. Active low. Indicates a distance reduction between the magnet and the device surface. 2 MagDECn Magnet Field Magnitude Decrease. Active low. Indicates a distance increase between the device and the magnet. 3 A_LSB_U Mode1.x: Quadrature A channel Mode2.x: Least Significant Bit Mode3.x: U signal (phase1) 4 B_Dir_V Mode1.x: Quadrature B channel quarter period shift to channel A Mode2.x: Direction of Rotation Mode3.x: V signal (phase2) 5 NC 6 Index_ W ams Datasheet [v1-08] 2015-Jan-16 Description For internal use. Must be left unconnected. Mode1.x and Mode2.x: Index signal indicates the absolute zero position Mode3.x: W signal (phase3) Page 3 Document Feedback AS5140H − Pin Assignment Pin Number Pin Name Description 7 VSS Negative Supply Voltage (GND). 8 Prog OTP Programming Input and Data Input for Daisy Chain mode. Internal pull-down resistor (~74kΩ). May be connected to VSS if programming is not used. 9 DO Data Output of Synchronous Serial Interface. 10 CLK SSI Clock Input. Schmitt-Trigger input. 11 CSn Chip Select. Active low; Schmitt-Trigger input, internal pull-up resistor (~50kΩ) connect to VSS in incremental mode (see Incremental Power-up Lock Option on page 21) 12 PWM_LSB 13 NC For internal use. Must be left unconnected. 14 NC For internal use. Must be left unconnected. 15 VDD3V3 3V-Regulator Output (see Figure 38) 16 VDD5V Positive Supply Voltage 5V Pulse Width Modulation of approx. 1kHz; LSB in Mode3.x 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 contact-less push-button functionality. Pins 3, 4 and 6 are the incremental pulse output pins. The functionality of these pins can be configured through programming the one-time programmable (OTP) register. Figure 5: Pin Assignment for Different Incremental Output Modes Output Mode Pin 3 Pin 4 Pin 6 Pin 12 1.x: Quadrature A B Index PWM 2.x: Step/direction LSB Direction Index PWM 3.x: Commutation U V W LSB Mode 1.x: Quadrature A/B Output Represents the default quadrature A/B signal mode. Mode 2.x: Step / Direction Output Configures pin 3 to deliver up to 512 pulses (up to 1024 state changes) per revolution. It is equivalent to the LSB (least significant bit) of the absolute position value. Pin 4 provides the information of the rotational direction. Page 4 Document Feedback ams Datasheet [v1-08] 2015-Jan-16 AS5140H − Pin Assignment Note(s): Both modes (mode 1.x and mode 2.x) provide an index signal (1 pulse/revolution) with an adjustable width of one LSB or three LSB’s. Mode 3.x: Brushless DC Motor Commutation Mode In addition to the absolute encoder output over the SSI interface, this mode provides commutation signals for brushless DC motors with either one pole pair or two pole pair rotors. The commutation signals are usually provided by 3 discrete Hall switches, which are no longer required, as the AS5140H can fulfill two tasks in parallel: absolute encoder + BLDC motor commutation. In this mode, • Pin 12 provides the LSB output instead of the PWM (Pulse-Width-Modulation) signal. • Pin 8 (Prog) is also used to program the different incremental interface modes, the incremental resolution and the zero position into the OTP (see Incremental Mode Programming). This pin is also used as digital input to shift serial data through the device in Daisy Chain configuration, (see Figure 24). • Pin 11 Chip Select (CSn; active low) selects a device within a network of AS5140H 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 AS5140H). • Pin 12 allows a single wire output of the 10-bit absolute position value. The value is encoded into a pulse width modulated signal with 1μs pulse width per step (1μs to 1024μs over a full turn). By using an external low pass filter, the digital PWM signal is converted into an analog voltage, allowing a direct replacement of potentiometers. ams Datasheet [v1-08] 2015-Jan-16 Page 5 Document Feedback AS5140H − 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 Operating Conditions is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Figure 6: Absolute Maximum Ratings Parameter Min Max Units DC supply voltage at pin VDD5V -0.3 7 V DC supply voltage at pin VDD3V3 -0.3 5 V Input pin voltage -0.3 7 V Input current (latchup immunity) -100 100 mA Norm: JEDEC 78 kV Norm: MIL 883 E method 3015 Electrostatic discharge Storage temperature ±2 -55 150 ºC 260 ºC 5 85 % -40 150 ºC Body temperature (Lead-free package) Humidity non-condensing Ambient temperature Moisture Sensitivity Level (MSL) Page 6 Document Feedback 3 Comments Pins Prog, MagINCn, MagDECn, CLK, CSn t=20 to 40s, Norm: IPC/JEDEC J-Std-020C Lead finish 100% Sn “matte tin” Represents a maximum floor time of 168h ams Datasheet [v1-08] 2015-Jan-16 AS5140H − Electrical Characteristics Electrical Characteristics TAMB = -40 to 150ºC, VDD5V = 3.0-3.6V (3V operation) VDD5V = 4.5-5.5V (5V operation) unless otherwise noted. Figure 7: Operating Conditions Symbol Isupp Parameter Condition Min Typ Max Unit 16 21 mA 4.5 5.0 5.5 V 3.0 3.3 3.6 V 3.0 3.3 3.6 V 3.0 3.3 3.6 V 150 μs Supply current VDD5V External supply voltage at pin VDD5V VDD3V3 Internal regulator output voltage at pin VDD3V3 5V operation VDD5V VDD3V3 tpwrup3 External supply voltage at pin VDD5V, VDD3V3 3.3V operation (pins VDD5V and VDD3V3 connected) External VDD3V3 supply voltage rise time at power-up 10-90% level in 3.3V mode (pins VDD5V and VDD3V3 connected) 1 DC Characteristics for Digital Inputs and Outputs Figure 8: CMOS Schmitt-Trigger Inputs: CLK, CSn (CSn = Internal Pull-up) Symbol Parameter Condition Min VIH High level input voltage Normal operation 0.7 *VDD5V VIL Low level input voltage VION - VIOFF Typ Max 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 ams Datasheet [v1-08] 2015-Jan-16 Unit μA Page 7 Document Feedback AS5140H − Electrical Characteristics Figure 9: CMOS / Program Input: Prog Symbol Parameter VIH High level input voltage VPROG High level input voltage VIL Low level input voltage IiL Pull-up high level input current Condition Min Typ 0.7 *VDD5V During programming Max Unit 5 V Refer to Programming Conditions VDD5V:5.0V V 0.3 *VDD5V V 100 μA Max Unit VSS+0.4 V Figure 10: CMOS Output Open Drain: MagINCn, MagDECn Symbol Parameter VOL Low level output voltage IO IOZ Condition Min Typ VDD5V:4.5V 4 VDD5V:3V 2 Output current mA Open drain leakage current 1 μA Max Unit Figure 11: CMOS Output: A, B, Index, PWM Symbol Parameter VOH High level output voltage VOL Low level output voltage IO Condition Min Typ VDD5V-0.5 V VSS+0.4 VDD5V:4.5V 4 VDD5V:3V 2 Output current Page 8 Document Feedback V mA ams Datasheet [v1-08] 2015-Jan-16 AS5140H − Electrical Characteristics Figure 12: Tristate CMOS Output: DO Symbol Parameter VOH High level output voltage VOL Low level output voltage IO Condition Min Typ Max VDD5V-0.5 V VSS+0.4 VDD5V:4.5V 4 VDD5V:3V 2 Output current IOZ Unit V mA Tri-state leakage current μA 1 Magnetic Input Specification Figure 13: Electrical Characteristics Symbol Parameter Condition Min Typ Max Unit Magnetic Input Specification (Two-pole cylindrical diametrically magnetized source) dmag Diameter tmag Thickness 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 Constant magnetic stray field Field non-linearity fmag_abs Disp Input frequency (rotational speed of magnet) Displacement radius ams Datasheet [v1-08] 2015-Jan-16 4 6 mm 2.5 45 75 mT ± 10 mT Including offset gradient 5 % Absolute mode: 600 rpm @ readout of 1024 positions (see Figure 33) 10 Hz Incremental mode: no missing pulses at rotational speeds of up to 10.000 rpm (see Figure 33) 166 Max. X-Y offset between defined IC package center and magnet axis (see Figure 40) 0.25 Max. X-Y offset between chip center and magnet axis 0.485 mm Page 9 Document Feedback AS5140H − Electrical Characteristics Symbol Parameter Chip placement tolerance Recommended magnet material and temperature drift Condition Min Typ Placement tolerance of chip within IC package (see Figure 42) NdFeB (Neodymium Iron Boron) -0.12 SmCo (Samarium Cobalt) -0.035 Max Unit ±0.235 mm %/K Electrical System Specifications Figure 14: Electrical System Specifications Symbol RES Parameter Resolution(1) Condition LSB 9 bit Typ 0.352 deg Max Unit 10 bit 2.813 7 bit 8 bit Min Adjustable resolution only available for incremental output modes; Least significant bit, minimum step 10 bit 1.406 deg 0.703 0.352 Integral non-linearity (optimum)(2) Maximum error with respect to the best line fit. Verified at optimum magnet placement, TAMB =25ºC ±0.5 deg Integral non-linearity (optimum) Maximum error with respect to the best line fit. Verified at optimum magnet placement, TAMB = -40 to 150ºC ±0.9 deg INL Integral non-linearity Best line fit = (Errmax – Errmin) / 2 Over displacement tolerance with 6mm diameter magnet, TAMB = -40 to 150ºC (see Figure 19) ±1.4 deg DNL Differential non-linearity(3) 10bit, no missing codes ±0.176 deg Transition noise(4) RMS equivalent to 1 sigma 0.12 Deg RMS Hysteresis Incremental modes only INLopt INLtemp TN Hyst Page 10 Document Feedback 0.704 deg ams Datasheet [v1-08] 2015-Jan-16 AS5140H − Electrical Characteristics Symbol Parameter VON Power-on reset thresholds On voltage; 300mV typ. hysteresis VOFF Power-on reset thresholds OFF voltage; 300mV typ. hysteresis Condition Min Typ Max 1.37 2.2 2.9 DC supply voltage 3.3V (VDD3V3) Unit V 1.08 1.9 2.6 tPwrUp Power-up time Until offset compensation finished 50 ms tdelay System propagation delay absolute output Includes delay of ADC and DSP 48 μs System propagation delay incremental output Calculation over two samples 192 μs fS CLK Sampling rate for absolute output Read-out frequency Internal sampling rate, TAMB = 25ºC Internal sampling rate, TAMB = -40 to 150ºC 9.90 10.42 10.94 kHz 9.38 10.42 11.46 Max. clock frequency to read out serial data 1 MHz Note(s) and/or Footnote(s): 1. Digital Interface. 2. Integral Non-Linearity (INL) is the maximum deviation between actual position and indicated position. 3. Differential Non-Linearity (DNL) is the maximum deviation of the step length from one position to the next. 4. Transition Noise (TN) is the repeatability of an indicated position. ams Datasheet [v1-08] 2015-Jan-16 Page 11 Document Feedback AS5140H − Electrical Characteristics Programming Conditions TAMB = -40 to 150ºC, VDD5V = 3.0-3.6V (3V operation) VDD5V = 4.5-5.5V (5V operation), unless otherwise noted. Figure 15: Programming Conditions Symbol Parameter VPROG Programming voltage Voltage applied during programming VProgOFF Programming voltage OFF level Line must be discharged to this level IPROG Programming current Current during programming Programmed fuse resistance (log 1) 10μA max. current @ 100mV Unprogrammed fuse resistance (log 0) 2mA max. current @ 100mV 50 100 Ω Programming time per bit Time to prog. a singe fuse bit 10 20 μs Refresh time per bit Time to charge the cap after tPROG 1 fLOAD LOAD frequency Data can be loaded at n*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 Rprogrammed Runprogrammed tPROG tCHARGE Page 12 Document Feedback Condition Min Typ Max Unit 3.0 3.3 3.6 V 1 V 100 mA 0 100k Ω μs ams Datasheet [v1-08] 2015-Jan-16 AS5140H − Electrical Characteristics Timing Characteristics TAMB = -40 to 150 ºC, VDD5V = 3.0 to 3.6V (3V operation) VDD5V = 4.5 to 5.5V (5V operation), unless otherwise noted Figure 16: Synchronous Serial Interface (SSI) Symbol Parameter Conditions Min Typ Max Unit s 100 ns 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 Data output valid Time between rising edge of CLK and data output valid 413 ns tDO tristate Data output tristate 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 tDO active tDO valid ns 1 MHz Units Figure 17: Pulse Width Modulation Output Symbol fPWM Parameter Conditions Min Typ Max Signal period = 1025μs ±5% at TAMB = 25ºC 0.927 0.976 1.024 PWM frequency kHz Signal period =1025μs ±10% at TAMB =-40 to 150ºC 0.878 0.976 1.074 PWMIN Minimum pulse width Position 0d; angle 0 degree 0.90 1 1.10 μs PWMAX Maximum pulse width Position 1023d; angle 359.65 degree 922 1024 1126 μs ams Datasheet [v1-08] 2015-Jan-16 Page 13 Document Feedback AS5140H − Electrical Characteristics Figure 18: Incremental Outputs Symbol tIncremental outputs valid tDir valid Parameter Conditions Min Typ Max Units Incremental outputs valid after power-up Time between first falling edge of CSn after power-up and valid incremental outputs 500 ns Directional indication valid Time between rising or falling edge of LSB output and valid directional indication 500 ns Figure 19: Integral and Differential Non-Linearity Example (Exaggerated Curve) 1023 D ELWFRGH 1023 $FWXDOFXUYH 2 71 1 0 512 ,GHDOFXUYH '1//6% ,1/ 512 0 0q Page 14 Document Feedback q 360 q D >GHJUHHV@ ams Datasheet [v1-08] 2015-Jan-16 AS5140H − Detailed Description Detailed Description The AS5140H 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 AS5140H 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 39). The AS5140H senses the orientation of the magnetic field and calculates a 10-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). Simultaneously, the device also provides incremental output signals. The various incremental output modes can be selected by programming the OTP mode register bits (see Figure 35). As long as no programming voltage is applied to pin Prog, the new setting may be overwritten at any time and will be reset to default when power is turned off. To make the setting permanent, the OTP register must be programmed. The default setting is a quadrature A/B mode including the Index signal with a pulse width of 1 LSB. The Index signal is logic high at the user programmable zero position. The AS5140H is tolerant to magnet misalignment and magnetic stray fields due to differential measurement technique and Hall sensor conditioning circuitry. Figure 20: Typical Arrangement of AS5140H and Magnet ams Datasheet [v1-08] 2015-Jan-16 Page 15 Document Feedback AS5140H − Detailed Description 10-bit Absolute Angular Position Output Synchronous Serial Interface (SSI) 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 t CLK 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 16 bits; the first 10 bits are the angular information D[9:0], 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 log “high” pulse at CSn with a minimum duration of tCSn. Figure 21: Synchronous Serial Interface with Absolute Angular Position Data &6Q W&6Q 7&/. W&/.)( W&/.)( &/. ' '2 W'2DFWLYH W'2YDOLG ' ' ' ' ' ' ' ' $QJXODU3RVLWLRQ'DWD ' 2&) &2) /,1 0DJ 0DJ (YHQ ,1& '(& 3$5 6WDWXV%LWV ' W'27ULVWDWH Data Content D9:D0 – Absolute angular position data (MSB is clocked out first). OCF – (Offset Compensation Finished). Logic high indicates the finished Offset Compensation Algorithm. For fast startup, this bit may be polled by the external microcontroller. As soon as this bit is set, the AS5140H has completed the startup and the data is valid (see Figure 23). COF – (Cordic Overflow). Logic high indicates an out of range error in the CORDIC part. When this bit is set, the data at D9:D0 is invalid. The absolute output maintains the last valid angular value. This alarm may be resolved by bringing the magnet within the X-Y-Z tolerance limits. Page 16 Document Feedback ams Datasheet [v1-08] 2015-Jan-16 AS5140H − Detailed Description LIN – (Linearity Alarm). Logic high indicates that the input field generates a critical output linearity. When this bit is set, the data at D9:D0 may still be used, but can contain invalid data. This warning may be resolved by bringing the magnet within the X-Y-Z tolerance limits. MagINCn – (Magnitude Increase) becomes HIGH, when the magnet is pushed towards the IC, thus increasing the magnetic field strength. MagDECn – (Magnitude Decrease) becomes HIGH, when the magnet is pulled away from the IC, thus decreasing the magnetic field strength. Signal “HIGH” for both MagINCn and MagDECn indicate a magnetic field that is out of the allowed range (see Figure 22). Figure 22: Magnetic Magnitude Variation Indicator MagINCn MagDECn Description 0 0 No distance change Magnetic Input Field OK (in range) 0 1 Distance increase: Pull-function. This state is dynamic, it is only active while the magnet is moving away from the chip in Z-axis. 1 0 Distance decrease: Push- function. This state is dynamic, it is only active while the magnet is moving towards the chip in Z.-axis. 1 1 Magnetic Input Field invalid – out of range: Too large, Too small (missing magnet). Note(s) and/or Footnote(s): 1. Pins 1 and 2 (MagINCn, MagDECn) are open drain outputs and require external pull-up resistors. If the magnetic field is in range, both outputs are turned OFF. The two pins may 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 22). Even Parity – A bit for transmission error detection of bits 1to 15 (D9 to D0, OCF, COF, LIN, MagINCn, MagDECn). The absolute angular output is always set to a resolution of 10 bit. Placing the magnet above the chip, angular values increase in clockwise direction by default. Data D9:D0 is valid, when the status bits have the following configurations: ams Datasheet [v1-08] 2015-Jan-16 Page 17 Document Feedback AS5140H − Detailed Description Figure 23: Status Bit Outputs OCF 1 COF 0 LIN MagINCn MagDECn 0 0 0 1 1 0 0 Parity even checksum of bits 1:15 The absolute angular position is sampled at a rate of 10kHz (0.1ms). This allows reading of all 1024 positions per 360 degrees within 0.1 seconds = 9.76Hz (~10Hz) without skipping any position. Multiplying 10Hz by 60, results the corresponding maximum rotational speed of 600rpm. Readout of every second angular position allows for rotational speeds of up to 1200 rpm. Consequently, increasing the rotational speed reduces the number of absolute angular positions per revolution (see Figure 45). Regardless of the rotational speed or the number of positions to be read out, the absolute angular value is always given at the highest resolution of 10 bit. The incremental outputs are not affected by rotational speed restrictions due to the implemented interpolator. The incremental output signals may be used for high-speed applications with rotational speeds of up to 10.000 rpm without missing pulses. Daisy Chain Mode The Daisy Chain mode allows connection of several AS5140H’s in series, while still keeping just one digital input for data transfer (see “Data IN” in Figure 24 below). This mode is accomplished by connecting the data output (DO; pin 9) to the data input (Prog; 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 Prog pin of the last device in the chain should be connected to VSS. The length of the serial bit stream increases with every connected device. It is, (EQ1) n * (16+1) bits For example, 34 bit for two devices, 51 bit for three devices, etc. The last data bit of the first device (Parity) is followed by a logic low bit and the first data bit of the second device (D9), etc. (see Figure 25). Page 18 Document Feedback ams Datasheet [v1-08] 2015-Jan-16 AS5140H − Detailed Description Figure 24: Daisy Chain Hardware Configuration AS5140H AS5140H μC st 2 1 Device 'DWD,1 3URJ '2 '2 AS5140H last Device Device 3URJ &6Q &/. &6Q nd '2 &/. 3URJ &6Q &/. &/. &6Q Figure 25: Daisy Chain Mode Data Transfer &6Q 7&/. W&/.)( &/. ' '2 W'2DFWLYH W'2YDOLG ' ' ' ' ' ' ' ' ' 2&) &2) $QJXODU3RVLWLRQ'DWD /,1 0DJ 0DJ (YHQ ,1& '(& 3$5 6WDWXV%LWV VW 'HYLFH ' ' ' ' $QJXODU3RVLWLRQ'DWD QG 'HYLFH Programming Daisy Chained Devices. In Daisy Chain mode, the Prog pin is connected directly to the DO pin of the subsequent device in the chain (see Figure 24). During programming (see Programming the AS5140H), a programming voltage of 7.5V must be applied to pin Prog. This voltage level exceeds the limits for pin DO, so one of the following precautions must be made during programming: • Open the connection DO→Prog during programming, (or) • Add a Schottky diode between DO and Prog (Anode = DO, Cathode = Prog) Due to the parallel connection of CLK and CSn, all connected devices may be programmed simultaneously. ams Datasheet [v1-08] 2015-Jan-16 Page 19 Document Feedback AS5140H − Detailed Description Incremental Outputs Three different incremental output modes are possible with quadrature A/B being the default mode. Figure 26 shows the two-channel quadrature as well as the step / direction incremental signal (LSB) and the direction bit in clockwise (CW) and counter-clockwise (CCW) direction. Quadrature A/B Output (Quad A/B Mode) The phase shift between channel A and B indicates the direction of the magnet movement. Channel A leads channel B at a clockwise rotation of the magnet (top view) by 90 electrical degrees. Channel B leads channel A at a counter-clockwise rotation. Figure 26: Incremental Output Modes 0HFKDQLFDO =HUR3RVLWLRQ 4XDG$%0RGH 0HFKDQLFDO =HUR3RVLWLRQ 5RWDWLRQ'LUHFWLRQ &KDQJH $ % ,QGH[ /6% ,QGH[ 6WHS'LU0RGH +\VW /6% ,QGH[ /6% /6% &ORFNZLVHFZ 'LU &6Q &RXQWHUFORFNZLVHFFZ W'LUYDOLG W,QFUHPHQWDORXWSXWVYDOLG Page 20 Document Feedback ams Datasheet [v1-08] 2015-Jan-16 AS5140H − Detailed Description LSB Output (Step/Direction Mode) Output LSB reflects the LSB (least significant bit) of the programmed incremental resolution (OTP Register Bit Div0, Div1). Output Dir provides information about the rotational direction of the magnet, which may be placed above or below the device (1=clockwise; 0=counter clockwise; top view). Dir is updated with every LSB change. In both modes (quad A/B, step/direction), the resolution and the index output are user programmable. The index pulse indicates the zero position and is by default one angular step (1LSB) wide. However, it can be set to three LSBs by programming the Index-bit of the OTP register accordingly (seeFigure 35). 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 (Rext ≤ 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) may 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 AS5140H 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. 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 2 LSB. Regardless of the programmed incremental resolution, the hysteresis of 2 LSB always corresponds to the highest resolution of 10 bit. In absolute terms, the hysteresis is set to 0.704 degrees for all resolutions. For constant rotational directions, every magnet position change is indicated at the incremental outputs (see Figure 27). 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 2 LSB, until position “x+2” is reached. Following this direction, the incremental outputs will again be updated with every change of the magnet position. ams Datasheet [v1-08] 2015-Jan-16 Page 21 Document Feedback AS5140H − Detailed Description Figure 27: Hysteresis Window for Incremental Outputs ,QFUHPHQWDO 2XWSXW ,QGLFDWLRQ +\VWHUHVLV ; ; ; ; ; ; 0DJQHW3RVLWLRQ ; ; ; ; ; &ORFNZLVH'LUHFWLRQ &RXQWHUFORFNZLVH'LUHFWLRQ Pulse Width Modulation (PWM) Output The AS5140H provides a pulse width modulated output (PWM), whose duty cycle is proportional to the measured angle: (EQ2) t ON ⋅ 1025 Position = ------------------------------- – 1 ( t ON + t OFF ) 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 28: PWM Output Signal $QJOH 3:0,1 GHJ 3RV V V 3:0$; GHJ 3RV V I3:0 Page 22 Document Feedback ams Datasheet [v1-08] 2015-Jan-16 AS5140H − Detailed Description Figure 29: PWM Signal Parameters Symbol Parameter Typ Unit Note fPWM PWM frequency 0.9756 kHz PWMIN MIN pulse width 1 μs Position 0d Angle 0 deg PWMAX MAX pulse width 1024 μs Position 1023d Angle 359.65 deg Signal period: 1025μs Analog Output An analog output may be generated by averaging the PWM signal, using an external active or passive lowpass filter. The analog output voltage is proportional to the angle: 0º = 0V; 360º = VDD5V. Using this method, the AS5140H can be used as direct replacement of potentiometers. Figure 30: Simple Passive 2nd Order Lowpass Filter 3LQ 5 5 DQDORJRXW 3:0 9'' & & 9 3LQ 966 (EQ3) R1, R2 ≥ 4k7 C1, C2 ≥ 1 μ F/6V R1 should be ≥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 [v1-08] 2015-Jan-16 Page 23 Document Feedback AS5140H − Detailed Description Brushless DC Motor Commutation Mode Brushless DC motors require angular information for stator commutation. The AS5140H provides U-V-W commutation signals for one and two pole pair motors. In addition to the three-phase output signals, the step (LSB) output at pin 12 allows high accuracy speed measurement. Two resolutions (9 or 10 bit) can be selected by programming Div0 according to Figure 35. Mode 3.0 (3.1) is used for brush-less DC motors with one-pole pair rotors. The three phases (U, V, W) are 120 degrees apart, each phase is 180 degrees on and 180 degrees OFF. Mode 3.2 (3.3) is used for motors with two pole pairs requiring a higher pulse count to ensure a proper current commutation. In this case the pulse width is 256 positions, equal to 90 degrees. The precise physical angle at which the U, V and W signals change state (“Angle” in Figure 31and Figure 32) is calculated by multiplying each transition position by the angular value of 1 count: (EQ4) Angle[deg] = Position x (360 degree/1024) Figure 31: U, V and W-Signals for BLDC Motor Commutation (Div1=0, Div0=0) Commutation - Mode 3.0 2QHSROHSDLU :LGWK6WHSV :LGWK6WHSV 8 9 : &:'LUHFWLRQ 3RVLWLRQ $QJOH Page 24 Document Feedback ams Datasheet [v1-08] 2015-Jan-16 AS5140H − Detailed Description Figure 32: U, V and W-Signals for 2Pole BLDC Motor Commutation (Div1=1, Div0=0) Commutation - Mode 3.2 7ZRSROHSDLUV :LGWK6WHSV :LGWK6WHSV 8 9 : &:'LUHFWLRQ 3RVLWLRQ $QJOH Programming the AS5140H Note(s): A detailed description of the ams low voltage polyfuse OTP programming method is given in Application Note AN514X-10, which can be downloaded from the ams website. The OTP programming description in this datasheet is for general information only. After power-on, programming the AS5140H is enabled with the rising edge of CSn with Prog = high and CLK = low. The AS5140H programming is a one-time-programming (OTP) method, based on polysilicon fuses. The advantage of this method is that a programming voltage of only 3.3V is required for programming. 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. ams Datasheet [v1-08] 2015-Jan-16 Page 25 Document Feedback AS5140H − Detailed Description The OTP memory can be accessed in several ways: • Load Operation: The Load operation reads the OTP fuses and loads the contents into the OTP register. Note that the 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. • 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. Page 26 Document Feedback ams Datasheet [v1-08] 2015-Jan-16 AS5140H − Detailed Description OTP Memory Assignment Figure 33: OTP Bit Assignment Symbol Md0 50 Md1 49 Div0 48 Div1 47 Index 46 Z0 : : 37 Z9 36 CCW 35 RA0 : : 31 RA4 30 FS 0 : : 18 FS 12 17 ChipID0 16 ChipID1 : : 0 ChipID17 Incremental output mode selection Customer Section 51 Factory Bit 1 10-bit Zero Position Direction Redundancy Address Factory Section mbit1 Function Factory Bit ID Section Bit 18-bit Chip ID mbit0 Factory Bit 0 User Selectable Settings The AS5140H allows programming of the following user selectable options: • Md1, Md0: Incremental Output Mode Selection. • Div1, Div0: Divider Setting of Incremental Output. • Index: Index Pulse Width Selection – 1LSB / 3LSB. • Z [9:0]: Programmable Zero / Index Position. ams Datasheet [v1-08] 2015-Jan-16 Page 27 Document Feedback AS5140H − Detailed Description • 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 AS5140H can also be operated without programming. The default, un-programmed setting is as listed below. • Md0, MD1:00 = Incremental mode = quadrature. • Div0, Div1:00 = Incremental resolution = 10bit. • Index:0 = Index bit width = 1LSB. • Z9 to Z0:00 = No programmed zero position. • CCW:0 = Clockwise operation. • RA4 to RA0:0 = No OTP bit is selected. 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 RA5...0 in the OTP user settings. Example: Setting RA5 …0 to “00001” will select bit 51 = MD0, “00010” selects bit 50 = MD1, “10000” selects bit 36 = CCW, etc. OTP Register Entry and 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, PROG and CLK signals as shown in Figure 34. Figure 34: OTP Access Timing Diagram 6HWXS&RQGLWLRQ 273$FFHVV &6Q 352* &/. 2SHUDWLRQ0RGH6HOHFWLRQ Page 28 Document Feedback ([LW&RQGLWLRQ ams Datasheet [v1-08] 2015-Jan-16 AS5140H − Detailed Description Incremental Mode Programming The following three different incremental output modes are available: • Mode: Md1=0 / Md0=1 sets the AS5140H in quadrature mode. • Mode: Md1=1 / Md0=0 sets the AS5140H in step / direction mode (see Figure 5). In both modes listed above, the incremental resolution may be reduced from 10 bit down to 9, 8 or 7 bit using the divider OTP bits Div1 and Div0 (see Figure 35 below). • Mode: Md1=1 / Md0=1 sets the AS5140H in brushless DC motor commutation mode with an additional LSB incremental signal at pin 12 (PWM_LSB). To allow programming of all bits, the default factory setting is all bits = 0. This mode is equal to mode 1:0 (quadrature A/B, 1LSB index width, 256ppr). The absolute angular output value, by default, increases with clockwise rotation of the magnet (top view). Setting the CCW-bit (see Figure 33) allows for reversing the indicated direction, e.g. when the magnet is placed underneath the IC: • CCW = 0 – angular value increases clockwise; • CCW = 1 – angular value increases counterclockwise. By default, the zero / index position pulse is one LSB wide. It can be increased to a three LSB wide pulse by setting the Index-bit of the OTP register. Further programming options (commutation modes) are available for brushless DC motor-control. Md1 = Md0 = 1 changes the incremental output pins 3, 4 and 6 to a 3-phase commutation signal. Div1 defines the number of pulses per revolution for either a two-pole (Div1=0) or four-pole (Div1=1) rotor. In addition, the LSB is available at pin 12 (the LSB signal replaces the PWM-signal), which allows for high rotational speed measurement of up to 10.000 rpm. ams Datasheet [v1-08] 2015-Jan-16 Page 29 Document Feedback A S 5 1 4 0 H − Detailed Description Figure 35: One Time Programmable (OTP) Register Options OTP-Mode-Register-Bit Pin# Mode Md1 Md0 Div1 Div0 Index default (Mode0.0) (1) 0 0 0 0 0 1LSB quadAB-Mode1.0 0 1 0 0 0 1LSB quadAB-Mode1.1 0 1 0 0 1 3LSBs quadAB-Mode1.2 0 1 0 1 0 1LSB quadAB-Mode 1.3 0 1 0 1 1 quadAB-Mode 1.4 0 1 1 0 0 1LSB quadAB-Mode 1.5 0 1 1 0 1 3LSBs quadAB-Mode 1.6 0 1 1 1 0 1LSB quadAB-Mode 1.7 0 1 1 1 1 3LSBs Page 30 Document Feedback 3 A 4 B 6 3LSBs 12 PWM 10 bit Pulses Per Revolution (ppr) Incremental Resolution (bit) 2x256 10 2x128 9 2x64 8 2x32 7 ams Datasheet [v1-08] 2015-Jan-16 A S 5 1 4 0 H − Detailed Description OTP-Mode-Register-Bit Pin# Mode Md1 Md0 Div1 Div0 Index 3 Step/Dir-Mode 2.0 1 0 0 0 0 1LSB Step/Dir-Mode 2.1 1 0 0 0 1 3LSBs Step/Dir-Mode 2.2 1 1 0 1 0 1LSB Step/Dir-Mode 2.3 1 0 0 1 1 3LSBs LSB 4 6 Dir Step/Dir-Mode 2.4 1 0 1 0 0 1LSB Step/Dir-Mode 2.5 1 0 1 0 1 3LSBs Step/Dir-Mode 2.6 1 0 1 1 0 1LSB Step/Dir-Mode 2.7 1 0 1 1 0 3LSBs Commutation-Mode3.0 1 1 0 0 0 1 1 0 1 0 Commutation-Mode3.2 1 1 1 0 0 1 1 1 1 0 512 10 256 9 128 8 64 7 PWM 10 bit V(120º) W(240º) LSB 3x1 9 U’(0º,180º) Commutation-Mode3.3 Incremental Resolution (bit) 10 U(0º) Commutation-Mode3.1 12 Pulses Per Revolution (ppr) V’(60º, 240º) W’(120º, 300º) 10 LSB 2x3 9 Note(s) and/or Footnote(s): 1. Div1, Div0 and Index cannot be programmed in Mode 0:0. ams Datasheet [v1-08] 2015-Jan-16 Page 31 Document Feedback AS5140H − Detailed Description 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/index 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. 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 Prog = logic high (see Figure 37). The Data bits D9-D0 of the SSI change to a 10-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 may 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 Prog = low. Page 32 Document Feedback ams Datasheet [v1-08] 2015-Jan-16 AS5140H − Detailed Description Figure 36: Enabling the Alignment Mode 3URJ $OLJQ0RGHHQDEOH &6Q V PLQ 5HDGRXW YLD66, V PLQ Figure 37: Exiting Alignment Mode 3URJ H[LW$OLJQ0RGH &6Q 5HDGRXW YLD66, 3.3V / 5V Operation The AS5140H 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 38). For 5V operation, the 5V supply is connected to pin VDD5V, while VDD3V3 (LDO output) must be buffered by a 2.2...10μF capacitor, which is supposed to be placed close to the supply pin (see Figure 38). The VDD3V3 output is intended for internal use only. It must not be loaded with an external load. ams Datasheet [v1-08] 2015-Jan-16 Page 33 Document Feedback AS5140H − Detailed Description 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 (see Figure 38). A buffer capacitor of 100nF is recommended in both cases close to pin VDD5V. Note that pin VDD3V3 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 may lead to larger than normal jitter of the measured angle. Figure 38: Connections for 5V/3.3V Supply Voltages 5V Operation 3.3V Operation ) 9''9 9''9 Q 9''9 Q /'2 ,QWHUQDO 9'' 9''9 /'2 ,QWHUQDO 9'' '2 '2 9 , 1 7 ( 5 ) $ & ( 3:0B/6% &/. Page 34 Document Feedback 9 &6Q $B/6%B8 %B'LUB9 ,QGH[B: 3URJ 966 966 , 1 7 ( 5 ) $ & ( 3:0B/6% &/. &6Q $B/6%B8 %B'LUB9 ,QGH[B: 3URJ ams Datasheet [v1-08] 2015-Jan-16 AS5140H − Detailed Description Choosing the Proper Magnet Typically the magnet should be 6mm in diameter and ≥2.5mm in height. Magnetic materials such as rare earth AlNiCo, SmCo5 or NdFeB are recommended. The magnet’s field strength perpendicular to the die surface should be verified using a gaussmeter. The magnetic field Bv at a given distance, along a concentric circle with a radius of 1.1mm (R1), should be in the range of ±45mT …±75mT. (see Figure 39). 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 IC package as shown in Figure 40. Magnet Placement. The magnet’s center axis should be aligned within a displacement radius R d of 0.25mm from the defined center of the IC with reference to the edge of pin #1 (see Figure 40). This radius includes the placement tolerance of the chip within the SSOP-16 package (± 0.235mm). The displacement radius R d is 0.485mm with reference to the center of the chip (see Alignment Mode). The vertical distance should be chosen such that the magnetic field on the die surface is within the specified limits (see Figure 39). The typical distance “z” between the magnet and the package surface is 0.5mm to 1.8mm with the recommended magnet (6mm x 2.5mm). Larger gaps are possible, as long as the required magnetic field strength stays within the defined limits. A magnetic field outside the specified range may still produce usable results, but the out-of-range condition will be indicated by MagINCn (pin 1) and MagDECn (pin 2), (see Figure 22). ams Datasheet [v1-08] 2015-Jan-16 Page 35 Document Feedback AS5140H − Detailed Description Figure 39: Typical Magnet and Magnetic Field Distribution W\SPPGLDPHWHU N S 0DJQHWD[LV Magnet axis 5 9HUWLFDOILHOG FRPSRQHQW N S 5FRQFHQWULFFLUFOH UDGLXVPP 9HUWLFDOILHOG FRPSRQHQW %Y «P7 0 360 360 Figure 40: Defined IC Center and Magnet Displacement Radius PPPP PP < PP ; ; < $6+GLH &HQWHURIGLH 5DGLXVRIFLUFXODU+DOOVHQVRU Page 36 Document Feedback ams Datasheet [v1-08] 2015-Jan-16 AS5140H − Detailed Description Figure 41: Vertical Placement of the Magnet N N 'LHVXUIDFH S 3DFNDJHVXUIDFH = PPPP PPPP Simulation Modeling With reference to Figure 42, a diametrically magnetized permanent magnet is placed above or below the surface of the AS5140H. The chip use an array of Hall sensors to sample the vertical vector of a magnetic field distributed across the device package surface. The area of magnetic sensitivity is a circular locus of 1.1mm radius with respect to the center of the die. The Hall sensors in the area of magnetic sensitivity are grouped and configured such that orthogonally related components of the magnetic fields are sampled differentially. The differential signal Y1-Y2 will give a sine vector of the magnetic field. The differential signal X1-X2 will give an orthogonally related cosine vector of the magnetic field. ams Datasheet [v1-08] 2015-Jan-16 Page 37 Document Feedback AS5140H − Detailed Description Figure 42: Arrangement of Hall Sensor Array on Chip (Principle) PPPP PP < PP ; ; < $6+GLH &HQWHURIGLH 5DGLXVRIFLUFXODU+DOOVHQVRU The angular displacement (Θ) of the magnetic source with reference to the Hall sensor array may then be modelled by: (EQ5) ( Y1 – Y2 ) Θ = arc tan -------------------------- ± 0.5° ( X1 – X2 ) The ±0.5º angular error assumes a magnet optimally aligned over the center of the die and is a result of gain mismatch errors of the AS5140H. Placement tolerances of the die within the package are ±0.235mm in X and Y direction, using a reference point of the edge of pin #1 (Figure 42). In order to neglect the influence of external disturbing magnetic fields, a robust differential sampling and ratiometric calculation algorithm has been implemented. The differential sampling of the sine and cosine vectors removes any common mode error due to DC components introduced by the magnetic source itself or external disturbing magnetic fields. A ratiometric division of the sine and cosine vectors removes the need for an accurate absolute magnitude of the magnetic field and thus accurate Z-axis alignment of the magnetic source. The recommended differential input range of the magnetic field strength (B (X1-X2) ,B(Y1-Y2) ) is ±75mT at the surface of the die. In addition to this range, an additional offset of ±5mT, caused by unwanted external stray fields is allowed. The chip will continue to operate, but with degraded output linearity, if the signal field strength is outside the recommended range. Too strong magnetic fields will introduce errors due to saturation effects in the internal preamplifiers. Too weak magnetic fields will introduce errors due to noise becoming more dominant. Page 38 Document Feedback ams Datasheet [v1-08] 2015-Jan-16 AS5140H − Detailed Description Failure Diagnostics The AS5140H also offers several diagnostic and failure detection features, which are discussed in detail further in the document. Magnetic Field Strength Diagnosis By Software: The MagINCn and MagDECn 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 is 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 AS5140H 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) should be added between pin DO 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 22). In a failure case, either when the magnetic field is out of range or the power supply is missing, these outputs will become low. To ensure adequate low levels in case of a broken power supply to the AS5140H, 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. By Hardware - Incremental Outputs: In normal operation, pins A(#3), B(#4) and Index (#6) will never be high at the same time, as Index is only high when A=B=low. However, after a power-on-reset, if VDD is powered up or restarts after a power supply interruption, all three outputs will remain in high state until pin CSn is pulled low. If CSn is already tied to VSS during power-up, the incremental outputs will all be high until the internal offset compensation is finished (within t PwrUp). ams Datasheet [v1-08] 2015-Jan-16 Page 39 Document Feedback AS5140H − Detailed Description Angular Output Tolerances Accuracy Accuracy is defined as the error between the measured angle and the 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 = (Err max – Err min )/2 is specified as better than ±0.5 degrees @ 25ºC (see Figure 44). Misalignment of the magnet further reduces the accuracy. Figure 43 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 2x2 mm (79x79mil) with a step size of 100μm. For each misalignment step, the measurement as shown in Figure 44 is repeated and the accuracy (Err max – Err min)/2 (e.g. 0.25º in Figure 44) is entered as the Z-axis in the 3D-graph. Figure 43: Example of Linearity Error Over XY Misalignment 6 5 4 3 800 500 2 200 1 -100 -700 -1000 -1000 -800 -400 -600 -200 0 400 y Page 40 Document Feedback x -400 200 800 600 1000 0 ams Datasheet [v1-08] 2015-Jan-16 AS5140H − Detailed Description 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. Note(s): The magnet used for this measurement was a cylindrical NdFeB (Bomatec® BMN-35H) magnet with 6mm diameter and 2.5mm in height. Figure 44: 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) 1. 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 applying an averaging of readings. An averaging of 4 readings will reduce the transition noise by 50% = 0.03º rms (1 sigma). 1. Statistically, 1 sigma represents 68.27% of readings; 3 sigma represents 99.73% of readings. ams Datasheet [v1-08] 2015-Jan-16 Page 41 Document Feedback AS5140H − Detailed Description • 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 may again be 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 10.000 rpm and higher). High Speed Operation The AS5140H samples the angular value at a rate of 10.42k samples per second. Consequently, the incremental and the absolute outputs are updated each by 96μs. At a stationary position of the magnet, this sampling rate creates no additional error. Absolute Mode. With the given sampling rate of 10.4 kHz, the number of samples (n) per turn for a magnet rotating at high speed can be calculated by: (EQ6) 60 n = --------------------------rpm ⋅ 96μs In practice, there is no upper speed limit. The only restriction is that there will be fewer samples per revolution as the speed increases. Regardless of the rotational speed, the absolute angular value is always sampled at the highest resolution of 10 bit. Likewise, for a given number of samples per revolution (n), the maximum speed can be calculated by: (EQ7) 60 rpm = -------------------n ⋅ 96μs In absolute mode (serial interface and PWM output), 610 rpm is the maximum speed, where 1024 readings per revolution can be obtained. In incremental mode, the maximum error caused by the sampling rate of the ADCs is 0/+96μs. It has a peak of 1LSB = 0.35º at 610 rpm. At higher speeds, this error is reduced again due to interpolation and the output delay remains at 192μs as the DSP requires two sampling periods (2x96μs) to synthesize and redistribute any missing pulses. Incremental Mode. Incremental encoders are usually required to produce no missing pulses up to several thousand rpm. Therefore, the AS5140H has a built-in interpolator, which ensures that there are no missing pulses at the incremental outputs for rotational speeds of up to 10.000 rpm, even at the highest resolution of 10 bits (512 pulses per revolution). Page 42 Document Feedback ams Datasheet [v1-08] 2015-Jan-16 AS5140H − Detailed Description Figure 45: Speed Performance Absolute Output Mode Incremental Output Mode 610rpm = 1024 samples / turn 122rpm = 512 samples / turn 2441rpm = 256 samples / turn No missing pulses @ 10 bit resolution (512ppr): max. speed = 10.000 rpm etc. Propagation Delays The propagation delay is the delay between the time that a sample is taken until it is converted and available as angular data. This delay is 48μs for the absolute interface and 192μs for the incremental interface. Using the SSI interface for absolute data transmission, an additional delay must be considered, caused by the asynchronous sampling (t=0…1/fs) and the time it takes the external control unit to read and process the data. Angular Error Caused by Propagation Delay. A rotating magnet will therefore cause an angular error caused by the output delay. This error increases linearly with speed: (EQ8) e sampling = rpm * 6 * prop.delay Where: e sampling = 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 that is processing the data from the AS5140H, thus reducing the angular error caused by speed. Internal Timing Tolerance The AS5140H does not require an external ceramic resonator or quartz. All internal clock timings for the AS5140H 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 100μs (typ.) • Incremental outputs: The incremental outputs are updated every 100μs (typ.) ams Datasheet [v1-08] 2015-Jan-16 Page 43 Document Feedback AS5140H − Detailed Description • PWM output: A new angular value is updated every 100μs (typ.). The PWM pulse timings T ON and T OFF 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): (EQ9) t ON ⋅ 1025 Position = ------------------------------- – 1 ( t ON + t OFF ) Temperature Magnetic Temperature Coefficient. One of the major benefits of the AS5140H, in comparison 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 coefficient, the AS5140H automatically compensates for the varying magnetic field strength over temperature. The magnet’s temperature drift does not need to be considered, as the AS5140H operates with magnetic field strengths from ±45 …±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 -40ºto 150º = 190K. The magnetic field change is: 190 x -0.12% = -22.8%, which corresponds to 75mT at -40ºC and 57.9mT at 150ºC. In the above described scenario, the AS5140H can automatically compensate for the change in temperature related field strength. No user adjustment is required. Accuracy Over Temperature. The influence of temperature in the absolute accuracy is very low. While the accuracy is ≤ ±0.5º at room temperature, it may increase 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 may 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 (see Internal Timing Tolerance). Page 44 Document Feedback ams Datasheet [v1-08] 2015-Jan-16 AS5140H − Application Information The benefits of AS5140H are as follows: Application Information • Complete system-on-chip • Flexible system solution provides absolute, PWM and incremental outputs simultaneously • Ideal for applications in harsh environments due to contactless position sensing • Tolerant to magnet misalignment and airgap variations • Tolerant to external magnetic fields • Operates up to 150ºC ambient temperature • No temperature compensation necessary • No calibration required • 10, 9, 8 or 7-bit user programmable resolution • Small Pb-free package: SSOP 16 (5.3mm x 6.2mm) AS5140H Differences to AS5040 The AS5140H and AS5040 differ in the following features: Figure 46: Differences Between AS5140H and AS5040 Parameter AS5140H Pin - assignment AS5040 Pin - compatible Ambient temperature range -40ºC …150ºC -40ºC … 125ºC Alignment mode Exit alignment mode by power-on-reset, Exit alignment mode by POR or with PROG=low @ falling edge of CSn. Exit alignment mode by power-on-reset only. OTP programming voltage 3.0 to 3.6V 7.3 to 7.5V OTP programming options Incremental modes (quad AB, step/dir, BLDC) Incremental resolution Incremental Index bit width 10-bit Zero position Direction bit (cw/ccw) Redundancy address (1 of 16) 18-bit Chip-Identifier Incremental modes (quad AB, step/dir, BLDC) Incremental resolution Incremental Index bit width 10-bit Zero position Direction bit (cw/ccw) OTP Programming protocol CSn, Prog and CLK; 52-bit serial data protocol CSn, Prog and CLK; 16-bit (32-bit) serial data protocol ams Datasheet [v1-08] 2015-Jan-16 Page 45 Document Feedback AS5140H − Package Drawings & Markings Package Drawings & Markings The device is available in a 16-Lead Shrink Small Outline Package. Figure 47: Package Drawings and Dimensions YYWWMZZ AS5140H Symbol Min Nom Max A A1 A2 b c D E E1 e L L1 L2 R Θ 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 0.30 017 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 Green RoHS Note(s) and/or Footnote(s): 1. Dimensions and tolerancing conform to ASME Y14.5M-1994. 2. All dimensions are in millimeters. Angles are in degrees. Figure 48: Package Marking: YYWWMZZ YY WW M ZZ Last two digits of the manufacturing year Manufacturing week Plant identifier Assembly traceability code Page 46 Document Feedback ams Datasheet [v1-08] 2015-Jan-16 AS5140H − Package Drawings & Markings Figure 49: Vertical Cross Section of SSOP-16 ams Datasheet [v1-08] 2015-Jan-16 Page 47 Document Feedback AS5140H − Package Drawings & Markings Recommended PCB Footprint Figure 50: PCB Footprint Figure 51: Recommended Footprint Data Page 48 Document Feedback Symbol mm inch A 9.02 0.355 B 6.16 0.242 C 0.46 0.018 D 0.65 0.025 E 5.01 0.197 ams Datasheet [v1-08] 2015-Jan-16 AS5140H − Ordering & Contact Information Ordering & Contact Information The devices are available as the standard products shown in Figure 52. Figure 52: Ordering Information Ordering Code Package Marking Delivery Form Delivery Quantity AS5140H-ASST SSOP-16 AS5140H Tape & Reel 2000 AS5140H-ASSM SSOP-16 AS5140H Tape & Reel 500 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 Unterpremstaetten Austria, Europe Tel: +43 (0) 3136 500 0 Website: www.ams.com ams Datasheet [v1-08] 2015-Jan-16 Page 49 Document Feedback AS5140H − 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 50 Document Feedback ams Datasheet [v1-08] 2015-Jan-16 AS5140H − Copyrights & Disclaimer Copyrights & Disclaimer Copyright ams AG, Tobelbader Strasse 30, 8141 Unterpremstaetten, 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 [v1-08] 2015-Jan-16 Page 51 Document Feedback AS5140H − Document Status Document Status Document Status Product Preview Preliminary Datasheet Datasheet Datasheet (discontinued) Page 52 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 [v1-08] 2015-Jan-16 AS5140H − Revision Information Revision Information Changes from 1.6 (2012-Mar-30) to current revision 1-08 (2015-Jan-16) Page Content of austriamicrosystems datasheet was converted to latest ams design Added Benefits to Key Features 1 Updated Figure 20 15 Updated Package Drawings & Markings section 46 Updated Ordering Information section 49 Note(s) and/or Footnote(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 [v1-08] 2015-Jan-16 Page 53 Document Feedback AS5140H − Content Guide Content Guide Page 54 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 7 9 10 12 13 Electrical Characteristics DC Characteristics for Digital Inputs and Outputs Magnetic Input Specification Electrical System Specifications Programming Conditions Timing Characteristics 15 16 16 18 20 20 21 21 22 23 24 25 27 27 28 28 28 29 32 32 33 35 35 37 39 39 39 40 40 41 42 43 43 44 Detailed Description 10-bit Absolute Angular Position Output Synchronous Serial Interface (SSI) Daisy Chain Mode Incremental Outputs Quadrature A/B Output (Quad A/B Mode) LSB Output (Step/Direction Mode) Incremental Output Hysteresis Pulse Width Modulation (PWM) Output Analog Output Brushless DC Motor Commutation Mode Programming the AS5140H OTP Memory Assignment User Selectable Settings OTP Default Setting Redundant Programming Option OTP Register Entry and Exit Condition Incremental Mode Programming Zero Position Programming Alignment Mode 3.3V / 5V Operation Choosing the Proper Magnet Physical Placement of the Magnet Simulation Modeling 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 ams Datasheet [v1-08] 2015-Jan-16 AS5140H − Content Guide ams Datasheet [v1-08] 2015-Jan-16 45 45 Application Information AS5140H Differences to AS5040 46 47 Package Drawings & Markings Recommended PCB Footprint 48 49 50 51 52 Ordering & Contact Information RoHS Compliant & ams Green Statement Copyrights & Disclaimer Document Status Revision Information Page 55 Document Feedback