AMIS-30622 I2C Micro-Stepping Motor Driver INTRODUCTION The AMIS−30622 is a single−chip micro−stepping motor driver with a position controller and control/diagnostic interface. It is ready to build intelligent peripheral systems where up to 32 drivers can be connected to one I2C master. This significantly reduces system complexity. The chip receives positioning instructions through the bus and subsequently drives the stator coils so the two−phase stepper motor moves to the desired position. The on−chip position controller is configurable (OTP or RAM) for different motor types, positioning ranges and parameters for speed, acceleration and deceleration. Micro−stepping allows silent motor operation and increased positioning resolution. The advanced motion qualification mode enables verification of the complete mechanical system in function of the selected motion parameters. The AMIS−30622 can easily be connected to an I2C bus where the I2C master can fetch specific status information like actual position, error flags, etc. from each individual slave node. The chip is implemented in I2T100 technology, enabling both high voltage analog circuitry and digital functionality on the same chip. http://onsemi.com SOIC−20 3 or 7 SUFFIX CASE 751AQ NQFP−32 8 SUFFIX CASE 560AA PRODUCT FEATURES Motor Driver • • • • • • Micro−Stepping Technology Peak Current Up to 800 mA Fixed Frequency PWM Current−Control Automatic Selection of Fast and Slow Decay Mode No external Fly−back Diodes Required 14 V/24 V Compliant ORDERING INFORMATION See detailed ordering and shipping information in the package dimensions section on page 2 of this data sheet. Controller with RAM and OTP Memory • Position Controller • Configurable Speeds and Acceleration • Input to Connect Optional Motion Switch I2C Interface • Bi−Directional 2−Wire Bus for Inter IC Control • Field Programmable Node Addresses • Full Diagnostics and Status Information Protection • • • • • Overcurrent Protection Undervoltage Management Open−circuit Detection High Temperature Warning and Management Low Temperature Flag © Semiconductor Components Industries, LLC, 2013 July, 2013 − Rev. 5 EMI Compatibility • High Voltage Outputs with Slope Control • This is a Pb−Free Device 1 Publication Order Number: AMIS−30622/D AMIS−30622 APPLICATIONS The AMIS−30622 is ideally suited for small positioning applications. Target markets include: automotive (headlamp alignment, HVAC, idle control, cruise control), industrial equipment (lighting, fluid control, labeling, process control, XYZ tables, robots) and building automation (HVAC, surveillance, satellite dish, renewable energy systems). Suitable applications typically have multiple axes or require mechatronic solutions with the driver chip mounted directly on the motor. Table 1. ORDERING INFORMATION Part No. Peak Current AMIS30622C6223G 800 mA AMIS30622C6223RG 800 mA AMIS30622C6227G 800 mA AMIS30622C6227RG 800 mA AMIS30622C6228G 800 mA AMIS30622C6228RG 800 mA Package* Shipping† SOIC−20 (Pb−Free) 38 Rail SOIC−20 (Pb−Free) 1500 Tape & Reel SOIC−20 (Pb−Free) 38 Rail SOIC−20 (Pb−Free) 1500 Tape & Reel NQFP−32 (7 x 7 mm) (Pb−Free) 40 Rail NQFP−32 (7 x 7 mm) (Pb−Free) 2500 Tape & Reel End Market/Version Automotive High Voltage Version Industrial High Voltage Version *For additional information on our Pb−Free strategy and soldering details, please download the ON Semiconductor Soldering and Mounting Techniques Reference Manual, SOLDERRM/D. †For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging Specification Brochure, BRD8011/D. QUICK REFERENCE DATA Table 2. ABSOLUTE MAXIMUM RATINGS Parameter Min Max Unit VBB, VHW, VSWI Supply voltage, hardwired address and SWI pins −0.3 +40 (Note 1) V TJ Junction temperature range (Note 2) −50 +175 °C Tst Storage temperature −55 +160 °C Vesd (Note 3) Human Body Model (HBM) Electrostatic discharge voltage on pins −2 +2 kV −200 +200 V Machine Model (MM) Electrostatic discharge voltage on pins Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect device reliability. 1. For limited time: VBB < 0.5 s, SWI and HW pins <1.0 s. 2. The circuit functionality is not guaranteed. 3. HBM according to AEC−Q100: EIA−JESD22−A114−B (100 pF via 1.5 kW) and MM according to AEC−Q100: EIA−JESD22−A115−A. Table 3. OPERATING RANGES Parameter Min Max Unit VBB Supply voltage +6.5 +29 V TJ Operating temperature range −40 +165 °C http://onsemi.com 2 AMIS−30622 Table of Contents Positioning Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Structural Description . . . . . . . . . . . . . . . . . . . . . . . . . 14 Functions Description . . . . . . . . . . . . . . . . . . . . . . . . . 15 Position Controller . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Main Control and Register . . . . . . . . . . . . . . . . . . . . . . 22 OTP Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 Priority Encoder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Motordriver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 I2C Bus Description . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 I2C Application Commands . . . . . . . . . . . . . . . . . . . . . 40 Package Outlines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Product Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Ordering Information . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Quick Reference Data . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Block Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Pin Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Package Thermal Resistance . . . . . . . . . . . . . . . . . . . . . 5 DC Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 AC Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Typical Application . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 SDA SCK SWI AMIS−30622 I2C−bus Interface Position Controller HW PWM regulator X Controller TST1 TST2 MOTXP MOTXN I−sense Decoder Main Control Registers OTP − ROM Sinewave Table Stall detection DAC’s 4MHz Temp sense Vref Voltage Regulator VBB VDD Oscillator PWM regulator Y Charge Pump CPN CPP I−sense VCP GND Figure 1. Block Diagram http://onsemi.com 3 MOTYP MOTYN AMIS−30622 GND GND YP YP XN XN GND GND 32 25 1 20 SWI SCK 2 19 VBB XP 1 31 30 29 28 27 26 24 YN VDD 3 18 MOTXP XP 2 23 YN GND 4 17 GND VBB 3 22 VBB MOTXN VBB 4 21 VBB VBB 5 20 VBB SWI 6 19 VCP NC 7 18 CPP SDA 8 10 11 12 13 14 15 17 CPN TST1 TST2 AMIS−30622 SDA 5 6 GND 7 HW 16 MOTYP 15 14 GND 8 13 MOTYN CPN 9 12 VBB CPP 10 11 VCP AMIS−30622 (Top View) 9 16 NC HW GND TST2 TST1 GND VDD SCK SOIC−20 Figure 2. SOIC−20 and NQFP−32 Pin−out Table 4. PIN DESCRIPTION Pin Name Pin Description SOIC−20 NQFP−32 SDA I2C 1 8 SCK I2C serial clock line 2 9 VDD Internal supply (needs external decoupling capacitor) 3 10 GND Ground, heat sink 4, 7, 14, 17 11, 14, 25, 26, 31, 32 TST1 Test pin (to be tied to ground in normal operation) 5 12 TST2 Test pin (to be left open in normal operation: internally pulled up) 6 13 serial data line HW Hard wired address bit 8 15 CPN Negative connection of pump−capacitor (charge pump) 9 17 CPP Positive connection of pump−capacitor (charge pump) 10 18 VCP Charge−pump filter−capacitor 11 19 VBB Battery voltage supply 12, 19 3, 4, 5, 20, 21, 22 MOTYN Negative end of phase Y coil 13 23, 24 MOTYP Positive end of phase Y coil 15 27, 28 MOTXN Negative end of phase X coil 16 29, 30 MOTXP Positive end of phase X coil 18 1, 2 SWI Switch input 20 6 NC Not connected (to be tied to ground) 7, 16 http://onsemi.com 4 AMIS−30622 PACKAGE THERMAL RESISTANCE The AMIS−30622 is available in SOIC−20 or optimized NQFP−32 packages. For cooling optimizations, the NQFP has an exposed thermal pad which has to be soldered to the PCB ground plane. The ground plane needs thermal vias to conduct the head to the bottom layer. Figures 3 and 4 give examples for good power distribution solutions. For precise thermal cooling calculations the major thermal resistances of the devices are given. The thermal media to which the power of the devices has to be given are: • Static environmental air (via the case) • PCB board copper area (via the device pins and exposed pad) The thermal resistances are presented in Table 5: DC Parameters. Package Rth Junction−to−Leads and Exposed Pad − Rthjp SOIC−20 NQFP−32 The major thermal resistances of the device are the Rth from the junction to the ambient (Rthja) and the overall Rth from the junction to the leads (Rthjp). The NQFP device is designed to provide superior thermal performance. Using an exposed die pad on the bottom surface of the package is mainly contributing to this performance. In order to take full advantage of the exposed pad, it is most important that the PCB has features to conduct heat away from the package. A thermal grounded pad with thermal vias can achieve this. In the table below, one can find the values for the Rthja and Rthjp, simulated according to the JESD−51 norm: Rth Junction−to−Leads Rthjp Rth Junction−to−Ambient Rthja (1S0P) Rth Junction−to−Ambient Rthja (2S2P) 19 62 39 60 30 0,95 The Rthja for 2S2P is simulated conform to JESD−51 as follows: • A 4−layer printed circuit board with inner power planes and outer (top and bottom) signal layers is used • Board thickness is 1.46 mm (FR4 PCB material) • The 2 signal layers: 70 mm thick copper with an area of 5500 mm2 copper and 20% conductivity • The 2 power internal planes: 36 mm thick copper with ÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎ ÏÏ ÎÎÎÎÎÎÎÎÎÎÎÎ ÏÏ ÎÎÎÎÎÎÎÎÎÎÎÎ ÏÏ ÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎ an area of 5500 mm2 copper and 90% conductivity The Rthja for 1S0P is simulated conform to JESD−51 as follows: • A 1−layer printed circuit board with only 1 layer • Board thickness is 1.46 mm (FR4 PCB material) • The layer has a thickness of 70 mm copper with an area of 5500 mm2 copper and 20% conductivity SOIC−20 NQFP−32 Figure 3. Example of SOIC−20 PCB Ground Plane Layout (preferred layout at top and bottom) Figure 4. Example of NQFP−32 PCB Ground Plane Layout (preferred layout at top and bottom) http://onsemi.com 5 AMIS−30622 DC PARAMETERS The DC parameters are guaranteed overtemperature and VBB in the operating range, unless otherwise specified. Convention: currents flowing into the circuit are defined as positive. Table 5. DC PARAMETERS Symbol Pin(s) Parameter Test Conditions Min Typ Max Unit IMSmax,Peak Max current through motor coil in normal operation VBB = 14 V 800 mA IMSmax,RMS Max rms current through coil in normal operation VBB = 14 V 570 mA Absolute error on coil current (Note 4) VBB = 14 V −10 VBB = 14 V −7 MOTORDRIVER IMSabs IMSrel RDS(on) MOTXP MOTXN Matching of X & Y MOTYP coil currents MOTYN On resistance for each motor pin at IMSmax (Note 5) IMSL I2C Pulldown current 10 % 0 7 % VBB = 12 V, Tj = 50°C 0.50 1 W VBB = 8 V, Tj = 50°C 0.55 1 W VBB = 12 V, Tj = 150°C 0.70 1 W VBB = 8 V, Tj = 150°C 0.85 1 W HiZ mode, VBB = 7.8 V 2 mA SERIAL INTERFACE VIL Input level low (Note 10) −0.5 0.3 * VDD V VIH Input level high (Note 11) 0.7 * VDD VDD + 0.5 V Noise margin at the LOW level for each connected device (including hysteresis) 0.1 * VDD Noise margin at the HIGH level for each connected device (including hysteresis) 0.2 * VDD VnL SDA SCK VnH V THERMAL WARNING & SHUTDOWN Ttw Thermal warning (Notes 6 and 7) 138 145 152 Ttsd Thermal shutdown (Note 8) Ttw + 10 °C Tlow Low temperature warning (Note 8) Ttw − 155 °C °C SUPPLY AND VOLTAGE REGULATOR VbbOTP UV1 UV2 Ibat VBB Supply voltage for OTP zapping (Note 9) 9.0 Stop voltage high threshold 7.7 Stop voltage low threshold 7.0 Total current consumption Unloaded outputs VBB = 29 V 10.0 V 8.3 8.9 V 7.5 8.0 V 3.50 10.0 mA 4. Tested in production for 800 mA, 400 mA, 200 mA and 100 mA current settings for both X and Y coil. 5. Not measured in production. Guaranteed by design. 6. Parameter guaranteed by trimming relevant OTP’s in production test at 143°C (±5°C) and VBB = 14 V. 7. No more than 100 cumulated hours in life time above Tw. 8. Thermal shutdown and low temperature warning are derived from thermal warning. Guaranteed by design. 9. A buffer capacitor of minimum 100 mF is needed between VBB and GND. Short connections to the power supply are recommended. 10. If input voltages < − 0.3 V, than a resistor between 22 W to 100 W needs to be put in series. 11. If the I2C−bus is operated in Fast Mode VIHmin = 0.7 * VDD. http://onsemi.com 6 AMIS−30622 Table 5. DC PARAMETERS Symbol Pin(s) Parameter Test Conditions Min Typ Max Unit 8 V < VBB < 29 V 4.75 5 5.50 V 4.5 V 45 mA SUPPLY AND VOLTAGE REGULATOR Regulated internal supply (Note 12) VDD VddReset VDD IddLim Digital supply reset level @ power down (Note 13) Current limitation Pin shorted to ground VBB = 14 V SWITCH INPUT AND HARDWIRE ADDRESS INPUT Switch OPEN resistance (Note 14) Rt_OFF Rt_ON Switch ON resistance SWI HW (Note 14) Vbb_sw VBB range for guaranteed operation of SWI and HW Ilim_sw Current limitation 10 kW Switch to GND or VBB 6 Short to GND or Vbat VBB = 29 V 20 Input level high VBB = 14 V 0.7 * Vdd Input level low VBB = 14 V Hysteresis VBB = 14 V 30 2 kW 29 V 45 mA TEST PINS Vihigh Vilow TSTx Vihyst V 0.3 * Vdd 0.075 * Vdd V V CHARGE PUMP Vcp Output voltage Cpump CPP CPN 2 * VBB − 2.5 V VBB + 10 VBB + 15 V External buffer capacitor 220 470 nF External pump capacitor 220 470 nF VCP Cbuffer 7 V ≤ VBB ≤ 14 V 14 V ≤ VBB ≤ 30 V PACKAGE THERMAL RESISTANCE VALUES Rthja SO Thermal resistance junction to ambient (2S2P) 39 K/W Rthjp SO Thermal resistance junction to leads 19 K/W Rthja NQ Thermal resistance junction to ambient (2S2P) 30 K/W Rthjp NQ Thermal resistance junction to leads and exposed pad 0.95 K/W Simulated conform JEDEC JESD51 12. Pin VDD must not be used for any external supply 13. The RAM content will not be altered above this voltage. 14. External resistance value seen from pin SWI or HW, including 1 kW series resistor. For the switch OPEN, the maximum allowed leakage current is represented by a minimum resistance seen from the pin. http://onsemi.com 7 AMIS−30622 AC PARAMETERS The AC parameters are guaranteed for temperature and VBB in the operating range unless otherwise specified. Table 6. AC PARAMETERS Symbol Pin(s) Parameter Test Conditions Min Typ Max Unit 10 ms 4.4 MHz 100 kHz POWERUP Power−up time Tpu Guaranteed by design INTERNAL OSCILLATOR Frequency of internal oscillator fosc VBB = 14 V 3.6 4.0 I2C TRANSCEIVER (STANDARD MODE) fSCL SCL clock frequency tHD,START Hold time (repeated) START condition. After this period the first clock pulse is generated. 4.0 ms tLOW LOW period of the SCK clock 4.7 ms tHIGH HIGH period of the SCK clock 4.0 ms Set−up time for a repeated START condition 4.7 tSU,START tHD,DATA SDA SCK tSU,DATA Data hold time for I2C bus devices 0 (Note 16) Data set−up time ms 3.45 (Note 17) 250 ms ns tR Rise time of SDA and SCK signals 1.0 ms tF Fall time of SDA and SCK signals 0.3 ms tSU,STOP tBUF Set−up time for STOP condition 4.0 ms Bus free time between STOP and START condition 4.7 ms I2C TRANSCEIVER (FAST MODE) fSCL SCL clock frequency tHD,START 360 kHz Hold time (repeated) START condition. After this period the first clock pulse is generated. 0.6 ms tLOW LOW period of the SCK clock 1.3 ms tHIGH HIGH period of the SCK clock 0.6 ms Set−up time for a repeated START condition 0.6 ms tSU,START tHD,DATA tSU,DATA Data hold time for SDA SCK I2C bus devices 0 (Note 16) Data set−up time 0.9 (Note 17) 100 (Note 18) ms ns tR Rise time of SDA and SCK signals 20 + 0.1 CB 300 ns tF Fall time of SDA and SCK signals 20 + 0.1 CB 300 ns tSU,STOP tBUF Set−up time for STOP condition 0.6 ms Bus free time between STOP and START condition 1.3 ms 15. The maximum number of connected I2C devices is dependent on the number of available addresses and the maximum bus capacitance to still guarantee the rise and fall times of the bus signals. 16. An I2C device must internally provide a hold time of at least 300 ns for the SDA signal (referred to the VIHmin of the SCL signal) to bridge the undefined region of the falling edge of SCL. 17. The maximum tHD,DAT has only to be met if the device does not stretch the LOW period (tLOW) of the SCL signal. 18. A Fast−mode I2C−bus device can be used in a standard−mode I2C bus system, but the requirement tSU,DATA w 250 ns must than be met. This will automatically be the case if the device does not stretch the LOW period of the SCL signal. If such a device does stretch the LOW period of the SCL signal, it must output the next data bit to the SDA line trmax + tSU,DATA = 1000 + 250 = 1250 ns (according to the standard−mode I2C−bus specification) before the SCL line is released. http://onsemi.com 8 AMIS−30622 Table 6. AC PARAMETERS Symbol Pin(s) Parameter Test Conditions Min Typ Max Unit SWITCH INPUT AND HARDWIRE ADDRESS INPUT Tsw SWI HW Tsw_on Scan pulse period (Note 19) VBB = 14 V 1024 ms Scan pulse duration (Note 19) VBB = 14 V 64 ms MOTORDRIVER Fpwm PWM frequency (Note 19) Tbrise Turn−on transient time MOTxx Tbfall 18 Between 10% and 90% Turn−off transient time Tstab Run current stabilization time (Note 19) 20 22 kHz 140 ns 130 ns 1/Vmin ms 250 kHz CHARGE PUMP fCP CPN CPP Charge pump frequency (Note 19) VBB = 14 V 19. Derived from the internal oscillator 20. See SetMotorParam START SDA REPEATED START STOP START VIHmin VILmax tF SCK tSU,DATA tR tHD,START tHD,DATA tLOW tBUF tSU,START tSP tHIGH Figure 5. I2C Timing Diagrams http://onsemi.com 9 tSU,STOP AMIS−30622 Typical Application VBAT C8 100 nF C7 100 mF C5 CPN VDD SDA I2C Bus Connect to VBAT or GND SCK 1k C1 HW C6 220 nF CPP VCP 10 9 3 C4 C3 220 nF 100 nF VBB VBB 11 19 20 12 1 18 AMIS−30622 2 8 15 13 6 5 4 7 1k SWI C2 2,7 nF MOTXP 14 MOTYP MOTYN 17 TST1 GND Figure 6. Typical Application Diagram for SO Device NOTES: All resistors are ± 5%, 1/4 W C1, C2 minimum value is 2.7 nF, maximum value is 10 nF Depending on the application, the ESR value and working voltage of C7 must be carefully chosen C3 and C4 must be close to pins VBB and GND C5 and C6 must be as close as possible to pins CPN, CPP, VCP, and VBB to reduce EMC radiation C9 must be a ceramic capacitor to assure low ESR http://onsemi.com 10 Connect to VBAT or GND 16 MOTXN 2,7 nF TST2 100 nF M AMIS−30622 POSITIONING PARAMETERS Stepping Modes Maximum Velocity One of four possible stepping modes can be programmed: • Half−stepping • 1/4 micro−stepping • 1/8 micro−stepping • 1/16 micro−stepping For each stepping mode, the maximum velocity Vmax can be programmed to 16 possible values given in the table below. The accuracy of Vmax is derived from the internal oscillator. Under special circumstances it is possible to change the Vmax parameter while a motion is ongoing. All 16 entries for the Vmax parameter are divided into four groups. When changing Vmax during a motion the application must take care that the new Vmax parameter stays within the same group. Table 7. MAXIMUM VELOCITY SELECTION TABLE Vmax Index Stepping Mode Half−stepping 1/4th Micro−stepping 1/8th Micro−stepping 1/16th Micro−stepping Hex Dec Vmax (full step/s) Group (half−step/s) (micro−step/s) (micro−step/s) (micro−step/s) 0 0 99 A 197 395 790 1579 1 1 136 273 546 1091 2182 2 2 167 334 668 1335 2670 3 3 197 395 790 1579 3159 4 4 213 425 851 1701 3403 5 5 228 456 912 1823 3647 6 6 243 486 973 1945 3891 7 7 273 546 1091 2182 4364 8 8 303 607 1213 2426 4852 9 9 334 668 1335 2670 5341 A 10 364 729 1457 2914 5829 B 11 395 790 1579 3159 6317 C 12 456 912 1823 3647 7294 D 13 546 1091 2182 4364 8728 E 14 729 1457 2914 5829 11658 F 15 973 1945 3891 7782 15564 B C D http://onsemi.com 11 AMIS−30622 Minimum Velocity Once the maximum velocity is chosen, 16 possible values can be programmed for the minimum velocity Vmin. The table below provides the obtainable values in full−step/s. The accuracy of Vmin is derived from the internal oscillator. Table 8. OBTAINABLE VALUES IN FULL−STEP/s FOR THE MINIMUM VELOCITY Vmax (Full−step/s) Vmin Index A Hex 99 136 167 197 213 228 243 273 303 334 364 395 456 546 729 973 Vmax Dec Factor B C D 0 0 1 99 136 167 197 213 228 243 273 303 334 364 395 456 546 729 973 1 1 1/32 3 4 5 6 6 7 7 8 8 10 10 11 13 15 19 27 2 2 2/32 6 8 10 11 12 13 14 15 17 19 21 23 27 31 42 57 3 3 3/32 9 12 15 18 19 21 22 25 27 31 32 36 42 50 65 88 4 4 4/32 12 16 20 24 26 28 30 32 36 40 44 48 55 65 88 118 5 5 5/32 15 21 26 31 32 35 37 42 46 51 55 61 71 84 111 149 6 6 6/32 18 25 31 36 39 42 45 50 55 61 67 72 84 99 134 179 7 7 7/32 21 30 36 43 46 50 52 59 65 72 78 86 99 118 156 210 8 8 8/32 24 33 41 49 52 56 60 67 74 82 90 97 113 134 179 240 9 9 9/32 28 38 47 55 59 64 68 76 84 93 101 111 128 153 202 271 A 10 10/32 31 42 51 61 66 71 75 84 93 103 113 122 141 168 225 301 B 11 11/32 34 47 57 68 72 78 83 93 103 114 124 135 156 187 248 332 C 12 12/32 37 51 62 73 79 85 91 101 113 124 135 147 170 202 271 362 D 13 13/32 40 55 68 80 86 93 98 111 122 135 147 160 185 221 294 393 E 14 14/32 43 59 72 86 93 99 106 118 132 145 158 172 198 237 317 423 F 15 15/32 46 64 78 93 99 107 113 128 141 156 170 185 214 256 340 454 NOTES: The Vmax factor is an approximation. In case of motion without acceleration (AccShape = 1) the length of the steps = 1/Vmin. In case of accelerated motion (AccShape = 0) the length of the first step is shorter than 1/Vmin depending of Vmin, Vmax and Acc. http://onsemi.com 12 AMIS−30622 Acceleration and Deceleration combinations of acceleration index and maximum speed (gray cells). The accuracy of Acc is derived from the internal oscillator. Sixteen possible values can be programmed for Acc (acceleration and deceleration between Vmin and Vmax). The table below provides the obtainable values in full−step/s2. One observes restrictions for some Table 9. ACCELERATION AND DECELERATION SELECTION TABLE Vmax (FS/s) " 99 136 167 197 213 228 243 273 303 334 364 395 456 546 729 973 O Acc Index Acceleration (Full−step/s2) Hex Dec 0 0 1 1 218 2 2 1004 3 3 3609 4 4 6228 5 5 8848 6 6 11409 7 7 13970 8 8 16531 9 9 19092 A 10 21886 B 11 24447 C 12 D 13 E 14 F 15 49 106 14785 473 735 27008 29570 34925 29570 40047 Positioning The formula to compute the number of equivalent full−steps during acceleration phase is: Nstep + Vmax 2 2 The position programmed in command SetPosition is given as a number of (micro−)steps. According to the chosen stepping mode, the position words must be aligned as described in the table below. When using command GotoSecurePosition, data is automatically aligned. Vmin 2 * Acc Table 10. POSITION WORD ALIGNMENT Stepping Mode Position Word: Pos[15:0] Shift 1/16th S B14 B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 LSB No shift 1/8th S B13 B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 LSB 0 1−bit left ⇔ ×2 1/4th S B12 B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 LSB 0 0 2−bit left ⇔ ×4 Half−stepping S B11 B10 B9 B8 B7 B6 B5 B4 B3 B2 B1 LSB 0 0 0 3−bit left ⇔ ×8 SecurePosition S B9 B7 B6 B5 B4 B3 B2 B1 LSB 0 0 0 0 0 No shift B8 NOTES: LSB: Least Significant Bit S: Sign bit http://onsemi.com 13 AMIS−30622 Position Ranges A position is coded by using the binary two’s complement format. According to the positioning commands used and to the chosen stepping mode, the position range will be as shown in the following table. Table 11. POSITION RANGE Command SetPosition Stepping Mode Position Range Full Range Excursion Number of Bits Half−stepping −4096 to +4095 8192 half−steps 13 1/4th micro−stepping −8192 to +8191 16384 micro−steps 14 1/8th micro−stepping −16384 to +16383 32768 micro−steps 15 −32768 to +32767 65536 micro−steps 16 1/16th micro−stepping Secure Position When using the command SetPosition, although coded on 16 bits, the position word will have to be shifted to the left by a certain number of bits, according to the stepping mode. A secure position can be programmed. It is coded in 11−bits, thus having a lower resolution than normal positions, as shown in the following table. See also command GotoSecurePosition. Table 12. SECURE POSITION Stepping Mode Secure Position Resolution Half−stepping 4 half−steps 1/4th micro−stepping 8 micro−steps (1/4th) 1/8th micro−stepping 16 micro−steps (1/8th) 1/16th micro−stepping 32 micro−steps (1/16th) Important NOTES: The secure position is disabled in case the programmed value is the reserved code “10000000000” (0x400 or most negative position). The resolution of the secure position is limited to 9 bit at start−up. The OTP register is copied in RAM as illustrated below. The RAM bits SecPos1 and SecPos0 are set to 0. SecPos10 SecPos9 SecPos8 SecPos2 SecPos10 SecPos9 SecPos8 SecPos2 SecPos1 SecPos0 RAM OTP • Shaft = 0 ⇒ MOTXP is used as positive pin of the X Shaft A shaft bit, which can be programmed in OTP or with command SetMotorParam, defines whether a positive motion is a clockwise (CW) or counter−clockwise rotation (CCW) (an outer or an inner motion for linear actuators): • coil, while MOTXN is the negative one. Shaft = 1 ⇒ opposite situation STRUCTURAL DESCRIPTION • The control block for the H−bridges, including the See also the Block Diagram in Figure 1. PWM control, the synchronous rectification and the internal current sensing circuitry. • The charge pump to allow driving of the H−bridges’ high side transistors. • Two pre−scale 4−bit DAC’s to set the maximum magnitude of the current through X and Y. • Two DAC’s to set the correct current ratio through X and Y. Battery voltage monitoring is also performed by this block, which provides the required information to the control logic part. The same applies for detection and Stepper Motordriver The Motordriver receives the control signals from the control logic. The main features are: • Two H−bridges, designed to drive a stepper motor with two separated coils. Each coil (X and Y) is driven by one H−bridge, and the driver controls the currents flowing through the coils. The rotational position of the rotor, in unloaded condition, is defined by the ratio of current flowing in X and Y. The torque of the stepper motor when unloaded is controlled by the magnitude of the currents in X and Y. http://onsemi.com 14 AMIS−30622 Miscellaneous reporting of an electrical problem that could occur on the coils or the charge pump. The AMIS−30622 also contains the following: • An internal oscillator, needed for the control logic Control Logic (Position Controller and Main Control) The control logic block stores the information provided by the I2C interface (in a RAM or an OTP memory) and digitally controls the positioning of the stepper motor in terms of speed and acceleration, by feeding the right signals to the motordriver state machine. It will take into account the successive positioning commands to properly initiate or stop the stepper motor in order to reach the set point in a minimum time. It also receives feedback from the motordriver part in order to manage possible problems and decide on internal actions and reporting to the I2C interface. • • • handler as well as the control logic and the PWM control of the motordriver. An internal trimmed voltage source for precise referencing. A protection block featuring a thermal shutdown and a power−on−reset circuit. A 5 V regulator (from the battery supply) to supply the internal logic circuitry. FUNCTIONS DESCRIPTION Position Controller This chapter describes the following functional blocks in more detail: • Position controller • Main control and register, OTP memory + ROM • Motordriver Ì Ì Ì Ì Ì Ì ÌÌ Ì Ì Positioning and Motion Control A positioning command will produce a motion as illustrated in Figure 7. A motion starts with an acceleration phase from minimum velocity (Vmin) to maximum velocity (Vmax) and ends with a symmetrical deceleration. This is defined by the control logic according to the position required by the application and the parameters programmed by the application during the configuration phase. The current in the coils is also programmable. Velocity Acceleration range Deceleration range Vmax Zero Speed Hold Current Zero Speed Hold Current Vmin Pstart P=0 Pmin ÌÌ ÌÌ ÌÌ ÌÌ ÌÌ ÌÌ ÌÌ ÌÌ ÌÌ ÌÌ Pstop Pmax Figure 7. Positioning and Motion Control http://onsemi.com 15 Position AMIS−30622 Table 13. POSITION RELATED PARAMETERS Parameter Reference Pmax – Pmin See Positioning Zero Speed Hold Current See Ihold Maximum Current See Irun Acceleration and Deceleration See Acceleration and Deceleration Vmin See Minimum Velocity Vmax See Maximum Velocity Different positioning examples are shown in the table below. Table 14. POSITIONING EXAMPLES Short motion. Velocity time New positioning command in same direction, shorter or longer, while a motion is running at maximum velocity. Velocity time New positioning command in same direction while in deceleration phase (Note 21) Note: there is no wait time between the deceleration phase and the new acceleration phase. Velocity New positioning command in reverse direction while motion is running at maximum velocity. Velocity time time New positioning command in reverse direction while in deceleration phase. Velocity time New velocity programming while motion is running. Velocity time 21. Reaching the end position is always guaranteed, however velocity rounding errors might occur after consecutive accelerations during a deceleration phase. The velocity rounding error will be removed at Vmin (e.g. at end of acceleration or when AccShape=1). http://onsemi.com 16 AMIS−30622 Dual Positioning A SetDualPosition command allows the user to perform a positioning using two different velocities. The first motion is done with the specified Vmin and Vmax velocities in the SetDualPosition command, with the acceleration (deceleration) parameter already in RAM, to a position Pos1[15:0] also specified in SetDualPosition. Then a second motion to a physical position Pos2[15:0] is done at the specified Vmin velocity in the SetDualPosition command (no acceleration). Once the second motion is achieved, the ActPos register is reset to zero, whereas TagPos register is not changed. When the Secure position is enabled, after the dual positioning, the secure positioning is executed. The figure below gives a detailed overview of the dual positioning function. After the dual positioning is executed an internal flag is set to indicate the AMIS−30622 is referenced. A new motion will start here Depends on AccShape Vmax Profile: Vmin first movement 27 ms 00 0 Motion status: 0 0 00 00 100 101 xx Pos: xx 27 ms Secure positioning (if enabled) 0 5 steps During one Vmin time the ActPos is 100 Position: second movement ActPos: 100 ActPos: 100 104 105 105 0 ActPos:0 60 ActPos: 60 Assume: First Position = 100 Second Position = 105 Secure Position = 60 ResetPos Figure 8. Dual Positioning Remark: This operation cannot be interrupted or influenced by any further command unless the occurrence of the conditions driving to a motor shutdown or by a HardStop command. Sending a SetDualPosition command while a motion is already ongoing is not recommended. 22. The priority encoder is describing the management of states and commands. 23. A DualPosition sequence starts by setting TagPos buffer register to SecPos value, provided secure position is enabled otherwise TagPos is reset to zero. If a SetPosition(Short) command is issued during a DualPosition sequence, it will be kept in the position buffer memory and executed afterwards. This applies also for the command GotoSecurePosition. 24. Commands such as GetFullStatus1 or GetFullStatus2 will be executed while a Dual Positioning is running. 25. The Pos1, Pos2, Vmax and Vmin values programmed in a SetDualPosition command apply only for this sequence. All other motion parameters are used from the RAM registers (programmed for instance by a former SetMotorParam command). After the DualPosition motion is completed, the former Vmin and Vmax become active again. 26. Commands ResetPosition, SetDualPosition, and SoftStop will be ignored while a DualPosition sequence is ongoing, and will not be executed afterwards. 27. Recommendation: a SetMotorParam command should not be sent during a SetDualPosition sequence: all the motion parameters defined in the command, except Vmin and Vmax, become active immediately. Position Periodicity The figure below illustrates that the moving direction going from ActPos = +30000 to TagPos = –30000 is clockwise. If a counter clockwise motion is required in this example, several consecutive SetPosition commands can be used. Depending on the stepping mode the position can range from −4096 to +4095 in half−step to −32768 to +32767 in 1/16th micro−stepping mode. One can project all these positions lying on a circle. When executing the command SetPosition, the position controller will set the movement direction in such a way that the traveled distance is minimal. http://onsemi.com 17 AMIS−30622 +10000 +20000 Hardwired Address HW In the drawing below, a simplified schematic diagram is shown of the HW comparator circuit. The HW pin is sensed via 2 switches. The DriveHS and DriveLS control lines are alternatively closing the top and bottom switch connecting HW pin with a current to resistor converter. Closing STOP (DriveHS = 1) will sense a current to GND. In that case the top I³ R converter output is low, via the closed passing switch SPASS_T this signal is fed to the “R” comparator which output HW_Cmp is high. Closing bottom switch SBOT (DriveLS = 1) will sense a current to VBAT. The corresponding I ³ R converter output is low and via SPASS_B fed to the comparator. The output HW_Cmp will be high. ActPos = +30000 0 Motion direction TagPos = −30000 −10000 −20000 Figure 9. Motion Direction is Function of Difference between ActPos and TagPos SPASS_T I/R State 1k STOP HW SBOT 1 2 1 = R2GND 2 = R2VBAT 3 = OPEN High DriveHS Low LOGIC DriveLS 3 ‘‘R”−Comp I/R SPASS_B Debouncer COMP Rth 32 ms HW_Cmp Figure 10. Simplified Schematic Diagram of the HW Comparator 3 cases can be distinguished (see also Figure 10 above): • HW is connected to ground: R2GND or drawing 1 • HW is connected to VBAT: R2VBAT or drawing 2 • HW is floating: OPEN or drawing 3 http://onsemi.com 18 Float AMIS−30622 Table 15. STATE DIAGRAM OF THE HW COMPARATOR Previous State DriveLS DriveHS HW_Cmp New State Condition Drawing Float 1 0 0 Float R2GND or OPEN 1 or 3 Float 1 0 1 High R2VBAT 2 Float 0 1 0 Float R2VBAT or OPEN 2 or 3 Float 0 1 1 Low R2GND 1 Low 1 0 0 Low R2GND or OPEN 1 or 3 Low 1 0 1 High R2VBAT 2 Low 0 1 0 Float R2VBAT or OPEN 2 or 3 Low 0 1 1 Low R2GND 1 High 1 0 0 Float R2GND or OPEN 1 or 3 High 1 0 1 High R2VBAT 2 High 0 1 0 High R2VBAT or OPEN 2 or 3 High 0 1 1 Low R2GND 1 As illustrated in the table above (Table 15), the state is depending on the previous state, the condition of the 2 switch controls (DriveLS and DriveHS) and the output of HW_Cmp. Figure 11 shows an example of a practical case where a connection to VBAT is interrupted. The logic is controlling the correct sequence in closing the switches and in interpreting the 32 ms debounced HW_Cmp output accordingly. The output of this small state−machine is corresponding to: • High or address = 1 • Low or address = 0 • Floating http://onsemi.com 19 AMIS−30622 Condition R2 VBAT OPEN R2 VBAT R2 GND t Tsw = 1024 ms DriveLS t Tsw_on = 64 ms DriveHS t “R”−Comp Rth t HW_Cmp t Low High Float High Float State t Figure 11. Timing Diagram Showing the Change in States for HW Comparator R2VBAT a motion to secure position after a debounce time of 64 ms, which prevents false triggering in case of micro− interruptions of the power supply. A resistor is connected between VBAT and HW. Every 1024 ms SBOT is closed and a current is sensed. The output of the I ⇒ R converter is low and the HW_Cmp output is high. Assuming the previous state was floating, the internal logic will interpret this as a change of state and the new state will be high (see also Table 15). The next time SBOT is closed the same conditions are observed. The previous state was high so based on Table 15 the new state remains unchanged. This high state will be interpreted as HW address = 1. R2GND If a resistor is connected between HW and the GND, a current is sensed every 1024 ms when STOP is closed. The output of the top I ⇒ R converter is low and as a result the HW_Cmp output switches to high. Again based on the stated diagram in Table 15 one can see that the state will change to Low. This low state will be interpreted as HW address = 0. OPEN External Switch SWI In case the HW connection is lost (broken wire, bad contact in connector) the next time SBOT is closed, this will be sensed. There will be no current, the output of the corresponding I ⇒ R converter is high and the HW_Cmp will be low. The previous state was high. Based in Table 15 one can see that the state changes to float. This will trigger As illustrated in Figure 12 the SWI comparator is almost identical to HW. The major difference is in the limited number of states. Only open or closed is recognized leading to respectively ESW = 0 and ESW = 1. http://onsemi.com 20 AMIS−30622 SPASS_T I/R State DriveHS STOP Closed 1k LOGIC SWI DriveLS Open SBOT 1 2 3 ‘‘R”−Comp 1 = R2GND 2 = R2VBAT 3 = OPEN I/R SPASS_B COMP 32 ms Debouncer SWI_Cmp Rth Figure 12. Simplified Schematic Diagram of the SWI Comparator As illustrated in the drawing above, a change in state is always synchronized with DriveHS or DriveLS. The same synchronization is valid for updating the internal position register. This means that after every current pulse (or closing of STOP or SBOT) the state of the position switch together with the corresponding position is memorized. The FullStatus1 command reads back the <ActPos> register and the status of ESW. In this way the master node may get synchronous information about the state of the switch together with the position of the motor. See Table 16 below. Table 16. GetFullStatus1 I2C COMMAND GetFullStatus1 Response Frame Structure Byte Content Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 Address 1 1 OTP3 OTP2 OTP1 OTP0 HW 1 1 Address 1 1 1 OTP3 OTP2 OTP1 OTP0 HW 2 Data 1 Irun[3:0] Ihold[3:0] 3 Data 2 Vmax[3:0] Vmin[3:0] 4 Data 3 AccShape 5 Data 4 VddReset 6 Data 5 7 Data 6 1 1 8 Data 7 1 1 StepMode[1:0] StepLoss Shaft ElDef Acc[3:0] UV2 TSD TW ESW OVC1 OVC2 1 CPFail 1 1 1 1 1 1 1 1 1 1 1 1 Motion[2:0] http://onsemi.com 21 Tinfo[1:0] AMIS−30622 DriveHS 512 ms Tsw = 1024 ms t Tsw_on = 64 ms DriveLS t “R”−Comp Rth t SWI_Cmp 60 ms t ESW 0 1 1 1 ActPos + 3 ActPos + 2 ActPos ActPos ActPos + 1 t t Figure 13. Simplified Timing Diagram Showing the Change in States for SWI Comparator Main Control and Register, OTP memory + ROM level), the H−bridges will be in high−impedance mode, and the registers and flags will be in a predetermined position. This is documented in Table 19: RAM Registers and Table 20: Flags Table. Power−up Phase Power−up phase of the AMIS−30622 will not exceed 10 ms. After this phase, the AMIS−30622 is in standby mode, ready to receive I2C messages and execute the associated commands. After power−up, the registers and flags are in the reset state, while some of them are being loaded with the OTP memory content (see Table 19: RAM Registers). Soft−stop A soft−stop is an immediate interruption of a motion, but with a deceleration phase. At the end of this action, the register <TagPos> is loaded with the value contained in register <ActPos>, see Table 19: Ram Registers). The circuit is then ready to execute a new positioning command, provided thermal and electrical conditions allow for it. Reset After power−up, or after a reset occurrence (e.g. a micro−cut on pin VBB has made VDD to go below VddReset http://onsemi.com 22 AMIS−30622 Thermal Shutdown Mode diagram and illustration of Figure 14: State Diagram Temperature Management below. The only condition to reset flags <TW> and <TSD> (respectively thermal warning and thermal shutdown) is to be at a temperature lower than Ttw and to get the occurrence of a GetFullStatus1 I2C frame. When thermal shutdown occurs, the circuit performs a <SoftStop> command and goes to motor shutdown mode (see Figure 14: State Diagram Temperature Management). Temperature Management The AMIS−30622 monitors temperature by means of two thresholds and one shutdown level, as illustrated in the state Normal Temp. − <Tinfo> = “00” − <TW> = ‘0’ − <TSD> = ‘0’ Thermal warning T° > Ttw T° > Ttsd −<Tinfo> = “10” −<TW> = ‘1’ −<TSD> = ‘0’ T° < Ttw & T° > Ttw I2C Frame: GetFullStatus1 T° < Ttw Post thermal warning Thermal shutdown − <Tinfo> = “11” − <TW> = ‘1’ − <TSD> = ‘1’ −SoftStop if motion ongoing − Motor shutdown (motion disabled) T° > Ttsd −<Tinfo> = “00” −<TW> = ‘1’ −<TSD> = ‘0’ T° < Tlow Post thermal shutdown 1 T° < Ttw T° > Tlow Low Temp. − <Tinfo> = “01” − <TW> = ‘0’ − <TSD> = ‘0’ Post thermal shutdown 2 − <Tinfo> = “00” − <TW> = ‘1’ − <TSD> = ‘1’ − Motor shutdown (motion disabled) − <Tinfo> = “10” − <TW> = ‘1’ − <TSD> = ‘1’ − Motor shutdown (motion disabled) T° > Ttw Figure 14. State Diagram Temperature Management http://onsemi.com 23 T° < Ttsd AMIS−30622 T shutdown level T T warning level t T <tw> bit T < Ttw and getfullstatus1 T <tsd> bit T > Ttsd, motor stops and shutdown T < Ttw and getfullstatus1 Figure 15. Illustration of Thermal Management Situation Battery Voltage Management to reset flags <UV2> and <StepLoss> is to recover by a battery voltage higher than UV1 and to receive a GetFullStatus1 command. The AMIS−30622 monitors the battery voltage by means of one threshold and one shutdown level. The only condition − <UV2> = ‘0’ − <Steploss> = ‘0’ NORMAL VOLTAGE VBB > UV1 VBB > UV1 & LIN Frame & LIN Frame <GetFullStatus> or <GetFullStatus> or <GetStatus <GetStatus> VBB < UV2 VBB < UV2 No Motion & Motion Ongoing − <UV2> = ‘1’ − <Steploss> = ‘0’ − Motor Shutdown STOP MODE 1 − <UV2> = ‘1’ − <Steploss> = ‘1’ − HardStop − Motor Shutdown STOP MODE 2 Figure 16. State Diagram Battery Voltage Management http://onsemi.com 24 AMIS−30622 In Stop mode 1 the motor is put in shutdown state. The <UV2> flag is set. In case VBB > UV1, AMIS−30622 accepts updates of the target position by means of the reception of SetPosition or GotoSecurePosition commands, only AFTER the <UV2> flag is cleared by receiving a GetFullStatus1 or GetFullStatus2 command. In Stop mode 2 the motor is stopped immediately and put in shutdown state. The <UV2> and <Steploss> flags are set. In case VBB > UV1, AMIS−30622 accepts updates of the target position by means of the reception of SetPosition or GotoSecurePosition commands, only AFTER the <UV2> and <Steploss> flags are cleared by receiving a GetFullStatus1 or GetFullStatus2 command. Important Notes: • In the case of Stop mode 2, care needs to be taken • • because the accumulated steploss can cause a significant deviation between physical and stored actual position. The SetDualPosition command will only be executed after clearing the <UV2> and <Steploss> flags. RAM reset occurs when VDD < VDDReset (digital POR level). OTP Register OTP Memory Structure The table below shows how the parameters to be stored in the OTP memory are located. Table 17. OTP MEMORY STRUCTURE Address Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0x00 OSC3 OSC2 OSC1 OSC0 IREF3 IREF2 IREF1 IREF0 0x01 0 TSD2 TSD1 TSD0 BG3 BG2 BG1 BG0 PA3 PA2 PA1 PA0 0x02 0x03 Irun3 Irun2 Irun1 Irun0 Ihold3 Ihold2 Ihold1 Ihold0 0x04 Vmax3 Vmax2 Vmax1 Vmax0 Vmin3 Vmin2 Vmin1 Vmin0 0x05 SecPos10 SecPos9 SecPos8 Shaft Acc3 Acc2 Acc1 Acc0 0x06 SecPos7 SecPos6 SecPos5 SecPos4 SecPos3 SecPos2 SecPos1 SecPos0 StepMode1 StepMode0 LOCKBT LOCKBG 0x07 Parameters stored at address 0x00 and 0x01 and bit <LOCKBT> are already programmed in the OTP memory at circuit delivery. They correspond to the calibration of the circuit and are just documented here as an indication. Each OTP bit is at ‘0’ when not zapped. Zapping a bit will set it to ‘1’. Thus only bits having to be at ‘1’ must be zapped. Zapping of a bit already at ‘1’ is disabled. Each OTP byte will be programmed separately (see command SetOTPparam). Once OTP programming is completed, bit <LOCKBG> can be zapped to disable future zapping, otherwise any OTP bit at ‘0’ could still be zapped by using a SetOTPparam command. programming is SetMotorParam. This allows for a functional verification before using a SetOTPparam command to program and zap separately one OTP memory byte. A GetOTPparam command issued after each SetOTPparam command allows verifying the correct byte zapping. Note: Zapped bits will become active only after a power cycle. After programming the I2C bits the power cycle has to be performed first to guarantee further communication with the device. Application Parameters Stored in OTP Memory Except for the physical address <PA[3:0]> these parameters, although programmed in a non−volatile memory can still be overridden in RAM by a I2C writing operation. PA[3:0] In combination with hired wired (HW) address, it forms the physical address AD[6:0] of the stepper−motor. Up to 32 stepper motors can theoretically be connected to the same I2C bus. Table 18. OTP OVERWRITE PROTECTION Lock Bit Protected Bytes LOCKBT (factory zapped before delivery) 0x00 to 0x01 LOCKBG 0x00 to 0x07 The command used to load the application parameters via the I2C bus in the RAM prior to an OTP Memory http://onsemi.com 25 AMIS−30622 Irun[3:0] Current amplitude value to be fed to each coil of the stepper−motor. The table below provides the 16 possible values for <IRUN>. Ihold[3:0] Hold current for each coil of the stepper−motor. The table below provides the 16 possible values for <IHOLD>. Index Run Current (mA) Index Irun Ihold Hold Current (mA) 0 0 0 0 0 59 0 0 0 0 0 59 1 0 0 0 1 71 1 0 0 0 1 71 2 0 0 1 0 84 2 0 0 1 0 84 3 0 0 1 1 100 3 0 0 1 1 100 4 0 1 0 0 119 4 0 1 0 0 119 5 0 1 0 1 141 5 0 1 0 1 141 6 0 1 1 0 168 6 0 1 1 0 168 7 0 1 1 1 200 7 0 1 1 1 200 8 1 0 0 0 238 8 1 0 0 0 238 9 1 0 0 1 283 9 1 0 0 1 283 A 1 0 1 0 336 A 1 0 1 0 336 B 1 0 1 1 400 B 1 0 1 1 400 C 1 1 0 0 476 C 1 1 0 0 476 D 1 1 0 1 566 D 1 1 0 1 566 E 1 1 1 0 673 E 1 1 1 0 673 F 1 1 1 1 800 F 1 1 1 1 800 Note: When the motor is stopped, the current is reduced from <IRUN> to <IHOLD>. StepMode Setting of step modes. StepMode Step Mode 0 0 1/2 stepping 0 1 1/4 stepping 1 0 1/8 stepping 1 1 1/16 stepping Shaft This bit distinguishes between a clock−wise or counter−clock−wise rotation. The shaft bit is not working in RunVelocity mode. SecPos[10:0] Secure Position of the stepper−motor. This is the position to which the motor is driven in case of a HW pin connection is lost. If <SecPos[10:0]> = “100 000000 00”, secure positioning is disabled; the stepper−motor will be kept in the position occupied at the moment these events occur. http://onsemi.com 26 AMIS−30622 Note: The Secure Position is coded on 11 bits only, providing actually the most significant bits of the position, the non coded least significant bits being set to ‘0’. Vmax[3:0] Maximum velocity Index Vmax Acc[3:0] Acceleration and deceleration between Vmax and Vmin. Index Acceleration (Full−step/s2) Acc 0 0 0 0 0 Vmax(full step/s) Group 49 (*) 1 0 0 0 A 2 0 0 1 1 218 (*) 0 1004 . 0 0 0 0 0 99 1 0 0 0 1 136 3 0 0 1 1 3609 . 2 0 0 1 0 167 4 0 1 0 0 6228 . 3 0 0 1 1 197 5 0 1 0 1 8848 . 4 0 1 0 0 213 6 0 1 1 0 11409 . 5 0 1 0 1 228 7 0 1 1 1 13970 . 6 0 1 1 0 243 8 1 0 0 0 16531 . 7 0 1 1 1 273 9 1 0 0 1 19092 (*) 8 1 0 0 0 303 A 1 0 1 0 21886 (*) 9 1 0 0 1 334 B 1 0 1 1 24447 (*) A 1 0 1 0 364 C 1 1 0 0 27008 (*) B 1 0 1 1 395 D 1 1 0 1 29570 (*) C 1 1 0 0 456 E 1 1 1 0 34925 (*) D 1 1 0 1 546 F 1 1 1 1 40047 (*) E 1 1 1 0 729 F 1 1 1 1 973 B C D (*) restriction on speed Vmin[3:0] Minimum velocity. Index Vmin Vmax Factor 0 0 0 0 0 1 1 0 0 0 1 1/32 2 0 0 1 0 2/32 3 0 0 1 1 3/32 4 0 1 0 0 4/32 5 0 1 0 1 5/32 6 0 1 1 0 6/32 7 0 1 1 1 7/32 8 1 0 0 0 8/32 9 1 0 0 1 9/32 A 1 0 1 0 10/32 B 1 0 1 1 11/32 C 1 1 0 0 12/32 D 1 1 0 1 13/32 E 1 1 1 0 14/32 F 1 1 1 1 15/32 http://onsemi.com 27 AMIS−30622 Table 19. RAM REGISTERS Mnemonic Length (bit) ActPos 16 GetFullStatus2 GotoSecurePos ResetPosition 16−bit signed Pos/TagPos 16/11 GetFullStatus2 GotoSecurePos ResetPosition SetPosition 16−bit signed or 11−bit signed for half stepping (see Positioning) AccShape 1 GetFullStatus1 SetMotorParam ResetToDefault ‘0’ ⇒ normal acceleration from Vmin to Vmax ‘1’ ⇒ motion at Vmin without acceleration Coil peak current Irun 4 GetFullStatus1 SetMotorParam ResetToDefault Operating current See look−up table Irun Coil hold current Ihold 4 GetFullStatus1 SetMotorParam ResetToDefault Standstill current See look−up table Ihold Minimum Velocity Vmin 4 GetFullStatus1 SetMotorParam ResetToDefault See Section Minimum Velocity See look−up table Vmin Maximum Velocity Vmax 4 GetFullStatus1 SetMotorParam ResetToDefault See Section Maximum Velocity See look−up table Vmax Register Actual position Last programmed Position Acceleration shape Shaft Related Commands Comment Shaft 1 GetFullStatus1 SetMotorParam ResetToDefault Direction of movement Acc 4 GetFullStatus1 SetMotorParam ResetToDefault See Section Acceleration See look−up table Acc Secure Position SecPos 11 GetFullStatus2 SetMotorParam ResetToDefault Target position when HW connection fails; 11 MSB’s of 16−bit position (LSB’s fixed to ‘0’) Stepping mode StepMode 2 GetFullStatus1 SetStallParam ResetToDefault See Section Stepping Modes See look−up table StepMode Acceleration/ deceleration Reset State ‘0’ From OTP memory 28. A ResetToDefault command will act as a reset of the RAM content, except for ActPos and TagPos, which are registers that are not modified. Therefore, the application should not send a ResetToDefault during a motion, to avoid any unwanted change of parameter. http://onsemi.com 28 AMIS−30622 Table 20. FLAGS TABLE Flag Mnemonic Length (bit) Related Commands Charge pump failure CPFail 1 GetFullStatus1 ‘0’ = charge pump OK ‘1’ = charge pump failure Resets only after GetFullStatus1 ‘0’ Electrical defect ElDef 1 GetFullStatus1 <OVC1> or <OVC2> or ‘open−load on coil X’ or ‘open−load on coil XY or <CPFail> Resets only after GetFullStatus1 ‘0’ External switch status ESW 1 GetFullStatus1 ‘0’ = open ‘1’ = close ‘0’ Electrical flag HS 1 Internal use <CPFail> or <UV2> or <ElDef> or <VDDreset> ‘0’ Motion status Motion 3 GetFullStatus1 “x00” = Stop “001” = inner (CCW) motion acceleration “010” = inner (CCW) motion deceleration “011” = inner (CCW) motion max. speed “101” = outer (CW) motion acceleration “110” = outer (CW) motion deceleration “111” = outer (CW) motion max. speed Comment Reset State “000” Over current in coil X OVC1 1 GetFullStatus1 ‘1’ = over current; reset only after GetFullStatus1 ‘0’ Over current in coil Y OVC2 1 GetFullStatus1 ‘1’ = over current; reset only after GetFullStatus1 ‘0’ Secure position enabled SecEn 1 Internal use ‘0’ if <SecPos> = “100 0000 0000” ‘1’ otherwise StepLoss 1 GetFullStatus1 ‘1’ = step loss due to under voltage, over current, open circuit or stall; Resets only after GetFullStatus1 Motor stop Stop 1 Internal use Temperature info Tinfo 2 GetFullStatus1 Step loss n.a. ‘1’ ‘0’ “00” = normal temperature range “01” = low temperature warning “10” = high temperature warning “11” = motor shutdown “00” Thermal shutdown TSD 1 GetFullStatus1 ‘1’ = shutdown (Tj > Ttsd) Resets only after GetFullStatus1 and if <Tinfo> = “00” ‘0’ Thermal warning TW 1 GetFullStatus1 ‘1’ = over temperature (Tj > Ttw) Resets only after GetFullStatus1 and if <Tinfo> = “00” ‘0’ Battery stop voltage UV2 1 GetFullStatus1 ‘0’ = VBB > UV2 ‘1’ = VBB ≤ UV2 Resets only after GetFullStatus1 ‘0’ Digital supply reset VddReset 1 GetActualPos GetStatus GetFullStatus1 Set at ‘1’ after power−up of the circuit. If this was due to a supply micro−cut, it warns that the RAM contents may have been lost; can be reset to ‘0’ with a Get(Full)Status1 command ‘1’ http://onsemi.com 29 AMIS−30622 Priority Encoder The table below describes the simplified state management performed by the main control block. Table 21. PRIORITY ENCODER State " Standby GotoPos DualPosition Motor Stopped, Ihold in Coils Motor Motion Ongoing No Influence on RAM and TagPos GetOTPparam OTP refresh; I2C slave response OTP refresh; I2C slave response GetFullStatus1 [attempt to clear all flags] (Note 29) I2C slave response GetFullStatus2 ResetToDefault [ ActPos and TagPos are not altered ] Command O SetMotorParam [Master takes care about proper update] RAM update Stopped HardStop ShutDown Motor Decelerating Motor Forced to Stop Motor Stopped, H−bridges in Hi−Z OTP refresh; I2C slave response OTP refresh; I2C slave response OTP refresh; I2C slave response OTP refresh; I2C slave response I2C slave response I2C slave response I2C slave response I2C slave response I2C slave response; if (<TSD> or <ElFlag> = ‘0’ then → Stopped I2C slave response I2C slave response I2C slave response I2C slave response I2C slave response I2C slave response OTP refresh; OTP to RAM; AccShape reset OTP refresh; OTP to RAM; AccShape reset OTP refresh; OTP to RAM; AccShape reset (Note 31) OTP refresh; OTP to RAM; AccShape reset OTP refresh; OTP to RAM; AccShape reset OTP refresh; OTP to RAM; AccShape reset RAM update RAM update RAM update RAM update RAM update RAM update ResetPosition <TagPos> and <ActPos> reset SetPosition <TagPos> updated; → GotoPos GotoSecPosition If <SecEn> = ‘1’ then <TagPos> = <SecPos>; → GotoPos DualPosition → DualPosition SoftStop <TagPos> and <ActPos> reset <TagPos> updated HardUnder ShutUnder RAM update RAM update <TagPos> and <ActPos> reset <TagPos> updated If <SecEn> = ‘1’ If <SecEn> = ‘1’ then <TagPos> = then <TagPos> = <SecPos> <SecPos> SoftStop → SoftStop HardStop → HardStop → HardStop → HardStop VBB < UV2 → HardUnder → HardUnder → HardStop → HardUnder <ElDef> = ‘1’ ⇒ <HS> = ‘1’ → Shutdown → HardStop; <StepLoss> = ‘1’ → HardStop; <StepLoss> = ‘1’ → HardStop; <StepLoss> = ‘1’ Thermal shutdown [<TSD> = ‘1’] → Shutdown → SoftStop → SoftStop Motion finished n.a. → Stopped → Stopped → Shutdown → Shutdown → Stopped; <TagPos> = <ActPos> → Stopped; <TagPos> = <ActPos> n.a. With the Following Color Code: Command Ignored NOTE: Transition to Another State Master is responsible for proper update (see Note 34) See table notes on the following page. http://onsemi.com 30 AMIS−30622 29. <ElFlag> = <CPFail> or <UV2> or <ElDef> or <VDDreset> 30. After power−on−reset, the <Standby> state is entered. 31. A DualPosition sequence runs with a separate set of RAM registers. The parameters that are not specified in a DualPosition command are loaded with the values stored in RAM at the moment the DualPosition sequence starts. <AccShape> is forced to ‘1’ during second motion. <AccShape> at ‘0’ will be taken into account after the DualPosition sequence. A GetFullStatus1 command will return the default parameters for <Vmax> and <Vmin> stored in RAM. 32. Shutdown state can be left only when <TSD> and <HS> flags are reset. 33. Flags can be reset only after the master could read them via a GetFullStatus1 command, and provided the physical conditions allow for it (normal temperature, correct battery voltage and no electrical or charge pump defect). 34. A SetMotorParam command sent while a motion is ongoing (state <GotoPos>) should not attempt to modify <Acc> and <Vmin> values. This can be done during a DualPosition sequence since this motion uses its own parameters, the new parameters will be taken into account at the next SetPosition command. 35. <SecEn> = ‘1’ when register <SecPos> is loaded with a value different from the most negative value (i.e. different from 0x400 = “100 0000 0000”). 36. <Stop> flag allows distinguishing whether state <Stopped> was entered after HardStop/SoftStop or not. <Stop> is set to ‘1’ when leaving state <HardStop> or <SoftStop> and is reset during first clock edge occurring in state <Stopped>. 37. While in state <Stopped>, if <ActPos> → <TagPos> there is a transition to state <GotoPos>. This transition has the lowest priority, meaning that <Stop>, <TSD>, etceteras are first evaluated for possible transitions. 38. If <StepLoss> is active, then SetPosition and GotoSecurePosition commands are not ignored. <StepLoss> can only be cleared by a GetFullStatus1 command. POR Thermal Shutdown Referencing HardStop Shutdown HardStop Thermal ShutDown SoftStop HardStop Dual Positioning Motion finished Motion Finished GotoSecPos HardStop Thermal Shutdown Soft−stop HardStop SetPosition Stopped Motion Finished GotoPos GetFullStatus1 Motion Finished Priorities 1 2 3 Vbb < UV2 or CPFAIL 4 Vbb < UV2 or CPFAIL HardStop Figure 17. Simplified State Diagram http://onsemi.com 31 AMIS−30622 Motordriver Current Waveforms in the Coils Figure 18 below illustrates the current fed to the motor coils by the motordriver in half−step mode. Ix Coil X Iy t Coil Y Figure 18. Current Waveforms in Motor Coils X and Y in Halfstep Mode Whereas Figure 19 below shows the current fed to the coils in 1/16th micro stepping (1 electrical period). Coil X Iy Ix t Coil Y Figure 19. Current Waveforms in Motor Coils X and Y in 1/16th Micro−Step Mode PWM Regulation regulation loop performs a comparison of the sensed output current to an internal reference, and features a digital regulation generating the PWM signal that drives the output switches. The zoom over one micro−step in the Figure 19 above shows how the PWM circuit performs this regulation. In order to force a given current (determined by <Irun> or <Ihold> and the current position of the rotor) through the motor coil while ensuring high energy transfer efficiency, a regulation based on PWM principle is used. The http://onsemi.com 32 AMIS−30622 Motor Starting Phase Motor Stopping Phase At motion start, the currents in the coils are directly switched from <Ihold> to <Irun> with a new sine/cosine ratio corresponding to the first half (or micro−) step of the motion. At the end of the deceleration phase, the currents are maintained in the coils at their actual DC level (hence keeping the sine/cosine ratio between coils) during the stabilization time tstab (see AC Table). The currents are then set to the hold values, respectively Ihold x sin(TagPos) and Ihold x cos(TagPos), as illustrated below. A new positioning order can then be executed. Iy Ix t Figure 20. Motor Stopping Phase t stab Charge Pump Monitoring Motor Shutdown Mode If the charge pump voltage is not sufficient for driving the high side transistors (due to failure), an internal HardStop command is issued. This is acknowledged to the master by raising flag <CPFail> (available with command GetFullStatus1). In case this failure occurs while a motion is ongoing, the flag <StepLoss> is also raised. A motor shutdown occurs when: • The chip temperature rises above the thermal shutdown threshold Ttsd (see Thermal Shutdown Mode). • The battery voltage goes below UV2 for longer than 15 seconds (see Battery Voltage Management). • The charge pump voltage goes below the charge pump comparator level for more than 15 seconds. • Flag <ElDef> = ‘1’, meaning an electrical problem is detected on one or both coils, e.g. a short circuit. Electrical Defect on Coils, Detection and Confirmation The principle relies on the detection of a voltage drop on at least one transistor of the H−bridge. Then the decision is taken to open the transistors of the defective bridge. This allows the detection the following short circuits: • External coil short circuit • Short between one terminal of the coil and Vbat or GND A motor shutdown leads to the following: • H−bridges in high impedance mode. • The <TagPos> register is loaded with the <ActPos>, except in autarkic states. The conditions to get out of a motor shutdown mode are: • Reception of a GetFullStatus1 command AND • The four above causes are no longer detected One cannot detect an internal short in the motor. Open circuits are detected by 100% PWM duty cycle value during one electrical period with duration, determined by Vmin. This leads to H−bridges going in Ihold mode. Hence, the circuit is ready to execute any positioning command. Table 22. ELECTRICAL DEFECT DETECTION Pins Fault Mode Yi or Xi Short−circuit to GND Yi or Xi Short−circuit to Vbat Yi or Xi Open Y1 and Y2 Short circuited X1 and X2 Short circuited Xi and Yi Short circuited http://onsemi.com 33 AMIS−30622 This can be illustrated in the following sequence given as an application example. The master can check whether there is a problem or not and decide which application strategy to adopt. Table 23. Example of Possible Sequence used to Detect and Determine Cause of Motor Shutdown Tj ≥ Tsd or VBB ≤ UV2 or <ElDef> = ‘1’ or <CPFail> = ‘1’ ↓ − The circuit is driven in motor shutdown mode − The application is not aware of this SetPosition frame ↓ − The position set−point is updated by the I2C Master − Motor shutdown mode ⇒ no motion − The application is still unaware GetFullStatus1 frame ↓ GetFullStatus1 frame ↓... − The application is aware of a problem − Possible confirmation of the problem − Reset <TW> or <TSD> or <UV2> or <StepLoss> or <ElDef> or <CPFail> by the application − Possible new detection of over temperature or low voltage or electrical problem ⇒ Circuit sets <TW> or <TSD> or <UV2> or <StepLoss> or <ElDef> or <CPFail> again at ‘1’ Warning: The application should limit the number of consecutive GetFullStatus1 commands to try to get the AMIS−30622 out of shutdown mode when this proves to be unsuccessful, e.g. there is a permanent defect. The reliability of the circuit could be altered since GetFullStatus1 attempts to disable the protection of the H−bridges. Important: While in shutdown mode, since there is no hold current in the coils, the mechanical load can cause a step loss, which indeed cannot be flagged by the AMIS−30622. Note: The Priority Encoder is describing the management of states and commands. http://onsemi.com 34 AMIS−30622 I2C BUS DESCRIPTION • No need to design bus interfaces because I2C−bus General Description AMIS−30622 uses a simple bi−directional 2−wire bus for efficient inter−ic control. This bus is called the Inter IC or I2C−bus. Features include: • Only two bus lines are required; a serial data line (SDA) and a serial clock line (SCK). • Each device connected to the bus is software addressable by a unique address and simple master/slave relationships exists at all times; master can operate as master−transmitter or as master receiver. • Serial, 8−bit oriented, bi−directional data transfers can be made up to 400 kb/s. • On−chip filtering rejects spikes on the bus data line to preserve data integrity. interface is already integrated on−chip. • IC’s can be added to or removed from a system without affecting any other circuits on the bus. Concept The I2C−bus consists of two wires, serial data (SDA) and serial clock (SCK), carrying information between the devices connected on the bus. Each device connected to the bus is recognized by a unique address and operates as either a transmitter or receiver, depending on the function of the device. AMIS−30622 can both receive and transmit data. In addition to transmitters and receivers, devices can also be considered as masters or slaves when performing data transfers. AMIS−30622 is a slave device. See Table 25. Table 24. DEFINITION OF I2C–BUS TERMINOLOGY Term Description Transmitter The device which sends data on the bus Receiver The device which receives data from the bus Master The device which initiates a transfer, generates clock signals and terminates a transfer Slave The devices addressed by a master Synchronization Procedure to synchronizer the clock signals of two or more devices Micro− controller Motordriver_2 Motordriver_4 AMIS−30622 AMIS−30622 SDA SCL Motordriver_1 Motordriver_3 AMIS−30622 AMIS−30622 Figure 21. Example of an I2C−bus Configuration Using One Microcontroller and Four Slaves 2. If the microcontroller wants to receive information from motordriver_2: ♦ Microcontroller (master) addresses motordriver_2 (slave) ♦ Microcontroller (master−receiver) receives data from motordriver_2 (slave−transmitter) ♦ Microcontroller terminates the transfer Even in this case the master generates the timing and terminates the transfer. Generation of the signals on the I2C−bus is always the responsibility of the master device. It generates its own clock signal when transferring data on the bus. Bus clock signals from a master can only be altered when they are stretched by a slow slave device holding−down the clock line. Figure 21 highlights the master−slave and receiver−transmitter relationships to be found on the I2C−bus. It should be noted that these relationships are not permanent but only depend on the direction of data transfer at that time. The transfer of data would proceed as follows: 1. Suppose the microcontroller wants to send information to motordriver_1: ♦ Microcontroller (master) addresses motordriver_1 (slave) ♦ Microcontroller (master−transmitter) sends data to motordriver_1 (slave−receiver) ♦ Microcontroller terminates the transfer http://onsemi.com 35 AMIS−30622 General Characteristics +5 V Rp Rp Serial Data Line Serial Clock Line SCK SDA 2 Clock IN SCL 1 Data IN Clock OUT SDA Clock IN Data OUT Data IN Clock OUT AMIS−30624, NCV70624 Data OUT MASTER Figure 22. Connection of a Device to the I2C−bus START and STOP Conditions Both SDA and SCK are bi−directional lines connected to a positive supply voltage via a pull−up resistor (see Figure 22). When the bus is free both lines are HIGH. The output stages of the devices connected to the bus must have an open drain to perform the wired−AND function. Data on the I2C−bus can be transferred up to 400 kb/s in fast mode. The number of interfaces connected to the bus is dependent on the maximum bus capacitance limit (See CB in Table 6) and the available number of addresses. Within the procedure of the I2C−bus, unique situations arise, which are defined as START (S) and STOP (P) conditions (See Figure 24). A HIGH to LOW transition on the SDA line while SCK is HIGH is one such unique case. This situation indicates a START condition. LOW to HIGH transition on the SDA line while SCK is HIGH defines a STOP condition. START and STOP conditions are always generated by the master. The bus is considered to be busy after the START condition. The bus is considered to be free again a certain time after the STOP condition. The bus free situation is specified as tBUF in Table 6. The bus stays busy if a repeated START (Sr) is generated instead of a STOP condition. In this respect, the START (S) and repeated START (Sr) conditions are functionally identical (See Figure 25). The symbol S will be used to represent START and repeated START, unless otherwise noted. Bit Transfer The levels for logic ‘0’ (LOW) and ‘1’ (HIGH) are not fixed in the I2C standard but dependent on the used VDD level. Using AMIS−30622, the levels are specified in Table 5. One clock pulse is generated for each data bit transferred. Data Validity The data on the SDA line must be stable during the HIGH period of the clock. The HIGH or LOW state of the data line can only change when the clock signal on the SCL line is LOW (See Figure 23). START STOP SDA SDA SCK SCK Data line stable −> Data valid Change of data allowed START condition Figure 23. Bit Transfer on the I2C−bus STOP condition Figure 24. START and STOP Conditions http://onsemi.com 36 AMIS−30622 Transferring Data most significant bit (MSB) first (See Figure 25). If a slave can’t receive or transmit another complete byte of data, it can hold the clock line SCK LOW to force the master into a wait state. Data transfer then continues when the slave is ready for another byte of data and releases clock line SCK. Byte Format Every byte put on the SDA line must be 8−bits long. The number of bytes that can be transmitted per transfer to AMIS−30622 is restricted to eight. Each byte has to be followed by an acknowledge bit. Data is transferred with the START STOP SDA MSB Acknowledgement signal from slave SCK 1 7 2 8 Clock line held low by slave 9 1 2 3−8 9 ACK START condition STOP condition Aknowledge related clock puse from master Figure 25. Data Transfer on the I2C−bus Acknowledge If AMIS−30622 as slave−receiver does acknowledge the slave address but later in the transfer cannot receive any more data bytes, this is indicated by generating a not−acknowledge on the first byte to follow. The master generates than a STOP or a repeated START condition. If a master−receiver is involved in the transfer, it must signal the end of data to the slave−transmitter by not generating an acknowledge on the last byte that was clocked out of the slave. AMIS−30622 as slave−transmitter shall release the data line to allow the master to generate STOP or repeated START condition. Data transfer with acknowledge is obligatory. The acknowledge−related clock pulse is generated by the master. The transmitter releases the SDA line (HIGH) during the acknowledge clock pulse. The receiver must pull down the SDA line during the acknowledge clock pulse so that it remains stable LOW during the HIGH period of this clock pulse (see Figure 26). Of course, set−up and hold times must also taken into account (see Table 6). When AMIS−30622 doesn’t acknowledge the slave address, the data line will be left HIGH. The master can than generate either a STOP condition to abort the transfer, or a repeated START condition to start a new transfer. START Master releases the Data line SDA by master transmitter MSB Not acknowledged SDA by slave receiver Acknowledged SCK from master 1 START condition 8 2 Slave pulls data line low if Acknowledged 9 Aknowledge related clock puse from master Figure 26. Acknowledge on the I2C−bus http://onsemi.com 37 AMIS−30622 Clock Generation address is 7−bit long followed by an eighth bit which is a data direction bit (R/W) − a ‘zero’ indicates a transmission (WRITE), a ‘one’ indicates a request for data (READ). A data transfer is always terminated by a STOP condition (P) generated by the master. The master generates the clock on the SCK line to transfer messages on the I2C−bus. Data is only valid during the HIGH period of the clock. Data Formats with 7−bit Addresses Data transfers follow the format shown in Figure 27. After the START condition (S), a slave address is sent. This START STOP SDA SCK 1−7 START condition ADDRESS 8 9 R/W ACK 8 1−7 9 DATA 1−7 ACK 9 8 DATA ACK STOP condition Figure 27. A Complete Data Transfer However, if a master still wishes to communicate on the bus, it can generate a repeated START (Sr) and address another slave without first generating a STOP condition. Various combinations of read/write formats are then possible within such a transfer. ♦ ♦ ♦ Data Transfer Formats Writing Data to AMIS−30622 When writing to AMIS−30622, the master−transmitter transmits to slave−receiver and the transfer direction is not changed. A complete transmission consists of: ♦ Start condition ♦ The slave address (7−bit) S Slave Address R/W A ♦ Data AMIS−30624 to Master A Data A P N bytes + Acknowledge ”0” = WRITE Master to AMIS−30624 Read/Write bit (‘0’ = write) Acknowledge bit Any further data bytes are followed by an acknowledge bit. The acknowledge bit is used to signal a correct reception of the data to the transmitter. In this case the AMIS−30622 pulls the SDA line to ‘0’. The AMIS−30622 reads the incoming data at SDA on every rising edge of the SCK signal Stop condition to finish the transmission S = Start condition P = Stop condition A = Acknowledge (SDA = LOW) A = No Acknowledge (SDA = HIGH) Figure 28. Master Writing Data to AMIS−30622 Some commands for the AMIS−30622 are supporting eight bytes of data, other commands are transmitting two bytes of data. See Table 25. 1. The first transmission consists of two bytes of data: ♦ The first byte contains the slave address and the write bit. ♦ The second byte contains the address of an internal register in the AMIS−30622. This internal register address is stored in the circuit RAM. Reading Data to AMIS−30622 When reading data from AMIS−30622 two transmissions are needed: http://onsemi.com 38 AMIS−30622 S Slave Address R/W A Internal Address A P ”0” = WRITE Figure 29. Master Reading Data from AMIS−30622: First Transmission is Addressing 2. The second transmission consists of the slave address and the read bit. Then the master can read the data bits on the SDA line on every rising edge of signal SCK. After each byte of data the master has to acknowledge correct data reception by S Slave Address R/W A pulling SDA LOW. The last byte is not acknowledged by the master and therefore the slave knows the end of transmission. Data Data A P N bytes + Acknowledge ”0” = WRITE Master to AMIS−30624 A S = Start condition P = Stop condition A = Acknowledge (SDA = LOW) A = No Acknowledge (SDA = HIGH) AMIS−30624 to Master Figure 30. Master Reading Data from AMIS−30622: Second Transmission is Reading Data Notes: 1. Each byte is followed by an acknowledgment bit as indicated by the A or A in the sequence. 2. I2C−bus compatible devices must reset their bus logic on receipt of a START condition such that they all anticipate the sending of a slave address, even if these START conditions are not positioned according to the proper format. 3. A START condition immediately followed by a STOP condition (void message) is an illegal format. 7−bit Addressing The addressing procedure for the I2C−bus is such that the first byte after the START condition usually determines which slave will be selected by the master. The exception is the general call address which can call all devices. When this address is used all devices should respond with an acknowledge. The second byte of the general call address then defines the action to be taken. AMIS−30622 is provided with a physical address in order to discriminate this circuit from other circuits on the I2C bus. This address is coded on seven bits (two bits being internally hardwired to ‘1’), yielding the theoretical possibility of 32 different circuits on the same bus. It is a combination of four OTP memory bits (OTP Memory Structure OPEN) and of the externally hardwired address bits (pin HW). HW must either be connected to ground or to Vbat. When HW is not connected and is left floating, correct functionality of the positioner is not guaranteed. The motor will be driven to the programmed secure position (See Hardwired Address – OPEN). Definition of Bits in the First Byte The first seven bits of the first byte make up the slave address. The eighth bit is the least significant bit (LSB). It determines the direction of the message. If the LSB is a “zero” it means that the master will write information to a selected slave. A “one” in this position means that the master will read information from the slave. When an address is sent, each device in a system compares the first seven bits after the START condition with its address. If they match, the device considers itself addressed by the master as a slave−receiver or slave−transmitter, depending on the R/W bit. MSB LSB MSB 1 1 PA3 PA2 PA1 PA0 HW R/W OTP memory Hardwired Address Bit Figure 32. First Byte after START Procedure LSB General Call Address R/W The AMIS−30622 supports also a “general call” address “000 0000”, which can address all devices. When this address is used all devices should respond with an acknowledge. The second byte of the general call address then defines the action to be taken. SLAVE ADDRESS Figure 31. First Byte after START Procedure http://onsemi.com 39 AMIS−30622 I2C APPLICATION COMMANDS Introduction Communications between the AMIS−30622 and a 2−wire serial bus interface master takes place via a large set of commands. Reading commands are used to: ♦ Get actual status information, e.g. error flags ♦ Get actual position of the stepper motor ♦ Verify the right programming and configuration of the AMIS−30622. Writing commands are used to: ♦ Program the OTP memory ♦ Configure the positioner with motion parameters (max/min speed, acceleration, stepping mode, etc.) ♦ Provide target positions to the Stepper motor The I2C−bus master will have to use commands to manage the different application tasks the AMIS−30622 can feature. The commands summary is given in Table 25. Commands Table Table 25. I2C COMMANDS WITH CORRESPONDING ROM POINTER Command Byte Command Mnemonic Function Binary Hexadecimal GetFullStatus1 Returns complete status of the chip “1000 0001” 0x81 GetFullStatus2 Returns actual, target and secure position “1111 1100” 0xFC GetOTPParam Returns OTP parameter “1000 0010” 0x82 GotoSecurePosition Drives motor to secure position “1000 0100” 0x84 HardStop Immediate full stop “1000 0101” 0x85 ResetPosition Sets actual position to zero “1000 0110” 0x86 ResetToDefault Overwrites the chip RAM with OTP contents “1000 0111” 0x87 SetDualPosition Drives the motor to two different positions with different speed “1000 1000” 0x88 SetMotorParam Sets motor parameter “1000 1001” 0x89 SetOTP Zaps the OTP memory “1001 0000” 0x90 SetPosition Programs a target and secure position “1000 1011” 0x8B SoftStop Motor stopping with deceleration phase “1000 1111” 0x8F These commands are described hereafter, with their corresponding I2C frames. Refer to Data Transfer Formats for more details. A color coding is used to distinguish between master and slave parts within the frames. An example is shown below. Light Gray: Master Data White: Slave Response Figure 33. Color Code Used in the Definition of I2C Frames http://onsemi.com 40 AMIS−30622 Application Commands Note: A GetFullStatus1 command will attempt to reset flags <TW>, <TSD>, <UV2>, <ElDef>, <StepLoss>, <CPFail>, <OVC1>, <OVC2>, and <VddReset>. GetFullStatus1 This command is provided to the circuit by the master to get a complete status of the circuit and of the stepper motor. Refer to Tables 19 and 20 to see the meaning of the parameters sent back to the I2C master. GetFullStatus1 corresponds to the following I2C command frame: Table 26. GetFullStatus1 COMMAND FRAME Structure Content Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 Address 1 1 OTP3 OTP2 OTP1 OTP0 HW 0 1 Command 1 0 0 0 0 0 0 1 Byte Table 27. GetFullStatus1 RESPONSE FRAME Structure Byte Content Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 Address 1 1 OTP3 OTP2 OTP1 OTP0 HW 1 1 Address 1 1 1 OTP3 OTP2 OTP1 OTP0 HW 2 Data 1 Irun[3:0] Ihold[3:0] 3 Data 2 Vmax[3:0] Vmin[3:0] 4 Data 3 AccShape 5 Data 4 VddReset 6 Data 5 7 Data 6 1 1 8 Data 7 1 1 Where: OTP(n) HW Irun[3:0] Ihold[3:0] Vmax[3:0] Vmin[3:0] AccShape StepMode[1:0] Shaft Acc[3:0] VddReset StepMode[1:0] StepLoss ElDef Shaft UV2 TSD TW ESW OVC1 OVC2 1 CPFail 1 1 1 1 1 1 1 1 1 1 1 1 Motion[2:0] StepLoss ElDef UV2 TSD TW Tinfo[1:0] Motion[2:0] ESW OVC1 OVC2 CPFail OTP address bits PA[3:0] Hardwired address bit Operating current in the motor coil Standstill current in the motor coil Maximum velocity Minimum velocity Enables motion without acceleration Step mode definition Direction of movement Acceleration form minimum to maximum velocity Reset of digital supply http://onsemi.com 41 Acc[3:0] Tinfo[1:0] Step loss occurred Electrical defect Battery under voltage detected Thermal shutdown Thermal warning Temperature Info Motion status External switch status Over current in X−coil detected Over current in Y−coil detected Charge pump failure AMIS−30622 GetFullStatus2 stepping mode the LSBs of ActPos[15:0] and TagPos[15:0] may have no meaning and should be assumed to be ‘0’. This command also gives additional information concerning stall detection. Refer to Tables 19 and 20 to see the meaning of the parameters sent back to the I2C master. This command is provided to the circuit by the master to get the actual, target and secure position of the stepper motor. Both the actual and target position are returned in signed two’s complement 16−bit format. Secure position is coded in 10−bit format. According to the programmed GetFullStatus2 corresponds to the following I2C command frame: Table 28. GetFullStatus2 COMMAND FRAME Structure Content Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 Address 1 1 OTP3 OTP2 OTP1 OTP0 HW 0 1 Command 1 1 1 1 1 1 0 0 Byte Table 29. GetFullStatus2 RESPONSE FRAME Structure Byte Content Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 Address 1 1 OTP3 OTP2 OTP1 OTP0 HW 1 1 Address 1 1 1 OTP3 OTP2 OTP1 OTP0 HW 2 Data 1 ActPos[15:8] 3 Data 2 ActPos[7:0] 4 Data 3 TagPos[15:8] 5 Data 4 TagPos[7:0] 6 Data 5 SecPos[7:0] 7 Data 6 1 1 1 1 1 8 Data 7 1 1 1 1 1 Where: OTP(n) HW ActPos[15:0] OTP address bits PA[3:0] Hardwired address bit Actual position TagPos[15:0] SecPos[10:0] http://onsemi.com 42 SecPos[10:8] 1 Target position Secure position 1 1 AMIS−30622 GetOTPParam This command is provided to the circuit by the I2C master to read the content of the OTP memory. More information can be found in OTP Memory Structure corresponds to the following I2C command frame:. GetOTPParam Table 30. GetOTPParam COMMAND FRAME Structure Byte Content Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 Address 1 1 OTP3 OTP2 OTP1 OTP0 HW 0 1 Command 1 0 0 0 0 0 1 0 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 OTP2 OTP1 OTP0 HW 1 Table 31. GetOTPParam RESPONSE FRAME Structure Content Bit 7 Bit 6 Bit 5 0 Address 1 1 OTP3 1 OTP byte 0 OTP byte @0x00 2 OTP byte 1 OTP byte @0x01 3 OTP byte 2 OTP byte @0x02 4 OTP byte 3 OTP byte @0x03 5 OTP byte 4 OTP byte @0x04 6 OTP byte 5 OTP byte @0x05 7 OTP byte 6 OTP byte @0x06 8 OTP byte 7 OTP byte @0x07 Byte the following I2C command frame: description for more details. The priority encoder table also acknowledges the cases where a GotoSecurePosition command will be ignored. GotoSecurePosition This command is provided by the I2C master to one or all the stepper motors to move to the secure position SecPos[10:0]. See the priority encoder corresponds to GotoSecurePosition Table 32. GotoSecurePosition COMMAND FRAME Structure Byte Content Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 Address 1 1 OTP3 OTP2 OTP1 OTP0 HW 0 1 Command 1 0 0 0 0 1 0 0 http://onsemi.com 43 AMIS−30622 HardStop master at the next GetStatus1 command that steps may have been lost. Once the motor is stopped, ActPos register is copied into TagPos register to ensure keeping the stop position. The I2C master for some safety reasons can also issue a HardStop command. This command will be internally triggered when an electrical problem is detected in one or both coils, leading to shutdown mode. If this occurs while the motor is moving, the <StepLoss> flag is raised to allow warning of the I2C HardStop corresponds to the following I2C command frame: Table 33. HardStop COMMAND FRAME Structure Content Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 Address 1 1 OTP3 OTP2 OTP1 OTP0 HW 0 1 Command 1 0 0 0 0 1 0 1 Byte ResetPosition This command is provided to the circuit by the I2C master to reset ActPos and TagPos registers to zero. This can be helpful to prepare for instance a relative positioning. ResetPosition corresponds to the following I2C command frame: Table 34. ResetPosition COMMAND FRAME Structure Byte Content Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 Address 1 1 OTP3 OTP2 OTP1 OTP0 HW 0 1 Command 1 0 0 0 0 1 1 0 Note: ActPos and TagPos are not modified by a ResetToDefault command. Important: Care should be taken not to send a ResetToDefault command while a motion is ongoing, since this could modify the motion parameters in a way forbidden by the position controller. ResetToDefault This command is provided to the circuit by the I2C master in order to reset the whole slave node into the initial state. ResetToDefault will, for instance, overwrite the RAM with the reset state of the registers parameters (see Table 19). This is another way for the I2C master to initialize a slave node in case of emergency, or simply to refresh the RAM content. ResetToDefault corresponds to the following I2C command frame: Table 35. ResetToDefault COMMAND FRAME Structure Byte Content Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 Address 1 1 OTP3 OTP2 OTP1 OTP0 HW 0 1 Command 1 0 0 0 0 1 1 1 RunVelocity This command is provided to the circuit by the I2C master in order to put the motor in continuous motion state. RunVelocity corresponds to the following I2C command frame: Table 36. RunVelocity COMMAND FRAME Structure Byte Content Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 Address 1 1 OTP3 OTP2 OTP1 OTP0 HW 0 1 Command 1 0 0 1 0 1 1 1 http://onsemi.com 44 AMIS−30622 SetDualPosition command is issued, the circuit will enter in deadlock state. Therefore, the application should check the actual position by a GetFullStatus2 corresponds to the following I2C command frame command prior to starting a dual positioning. Another solution may consist of programming a value out of the stepper motor range for Pos1[15:0]. For the same reason Pos2[15:0] should not be equal to Pos1[15:0]. This command is provided to the circuit by the I2C master in order to perform a positioning of the motor using two different velocities. See Section Dual Positioning. Note: This sequence cannot be interrupted by another positioning command. Important: If for some reason ActPos equals Pos1[15:0] at the moment the SetDualPosition SetDualPosition Table 37. SetDualPosition COMMAND FRAME Structure Content Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 Address 1 1 OTP3 OTP2 OTP1 OTP0 HW 0 1 Command 1 0 0 0 1 0 0 0 2 Data 1 1 1 1 1 1 1 1 1 3 Data 2 1 1 1 1 1 1 1 1 4 Data 3 5 Data 4 6 Data 5 Pos1[7:0] 7 Data 6 Pos2[15:8] 8 Data 7 Pos2[7:0] Byte Where: Vmax[3:0] Vmin[3:0] Vmax[3:0] Vmin[3:0] Pos1[15:8] Max. velocity for first motion Min. velocity for first motion and velocity for the second motion Pos1[15:0] Pos2[15:0] http://onsemi.com 45 First position to be reached during the first motion Relative position of the second motion AMIS−30622 SetMotorParam This command is provided to the circuit by the I2C master to set the values for the stepper motor parameters (listed below) in RAM. Refer to Table 19 to see the meaning of the parameters sent by the I2C master. Important: If a SetMotorParam occurs while a motion is ongoing, it will modify at once the motion parameters (see Position Controller corresponds to the following I2C command frame:). Therefore the application should not change parameters other than Vmax while a motion is running, otherwise correct positioning cannot be guaranteed. SetMotorParam Table 38. SetMotorParam COMMAND FRAME Structure Byte Content Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 Address 1 1 OTP3 OTP2 OTP1 OTP0 HW 0 1 Command 1 0 0 0 1 0 0 1 2 Data 1 1 1 1 1 1 1 1 1 3 Data 2 1 1 1 1 1 1 1 1 4 Data 3 Irun[3:0] Ihold[3:0] 5 Data 4 Vmax[3:0] Vmin[3:0] 6 Data 5 7 Data 6 8 Data 7 SecPos[10:8] Shaft Acc[3:0] SecPos[7:0] 1 1 1 AccShape StepMode[1:0] 1 1 SetOTPParam This command is provided to the circuit by the I2C master to program and zap the OTP data D[7:0] in OTP address OTPA[2:0]. Important: This command must be sent under a specific VBB voltage value. See parameter VBBOTP in Table 5. This is a mandatory condition to ensure reliable zapping. SetOTPParam corresponds to the following I2C command frame: Table 39. SetOTPParam COMMAND FRAME Structure Byte Content Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 Address 1 1 OTP3 OTP2 OTP1 OTP0 HW 0 1 Command 1 0 0 1 0 0 0 0 2 Data 1 1 1 1 1 1 1 1 1 3 Data 2 1 1 1 1 1 1 1 1 4 Data 3 1 1 1 1 1 5 Data 4 Where: OTPA[2:0]: D[7:0]: D[7:0] OTP address Corresponding OTP data http://onsemi.com 46 OTPA[2:0] AMIS−30622 SetPosition This command is provided to the circuit by the I2C master to drive the motor to a given absolute position. See Positioning (see Priority Encoder) for more details. The priority encoder table acknowledges the cases where a SetPosition command will be ignored. SetPosition corresponds to the following I2C command frame: Table 40. SetPosition COMMAND FRAME Structure Byte Content Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 Address 1 1 OTP3 OTP2 OTP1 OTP0 HW 0 1 Command 1 0 0 0 1 0 1 1 2 Data 1 1 1 1 1 1 1 1 1 3 Data 2 1 1 1 1 1 1 1 1 4 Data 3 Pos[15:8] 5 Data 4 Pos[7:0] Where: Pos [15:0] Signed 16−bit position set−point for motor. SoftStop This command will be internally triggered when the chip temperature rises above the thermal shutdown threshold (see Table 5 and the Temperature Management Section). It provokes an immediate deceleration to Vmin (see Minimum Velocity corresponds to the following I2C command frame:) followed by a stop, regardless of the position reached. Once the motor is stopped, TagPos register is overwritten with value in ActPos register to ensure keeping the stop position. The I2C Master for some safety reasons can also issue a SoftStop command. SoftStop Table 41. SoftStop COMMAND FRAME Structure Byte Content Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 0 Address 1 1 OTP3 OTP2 OTP1 OTP0 HW 0 1 Command 1 0 0 0 1 1 1 1 http://onsemi.com 47 AMIS−30622 PACKAGE DIMENSIONS SOIC 20 W CASE 751AQ ISSUE O http://onsemi.com 48 AMIS−30622 PACKAGE DIMENSIONS NQFP−32, 7x7 CASE 560AA ISSUE O http://onsemi.com 49 AMIS−30622 NQFP−32, 7x7 CASE 560AA ISSUE O ON Semiconductor and are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC owns the rights to a number of patents, trademarks, copyrights, trade secrets, and other intellectual property. A listing of SCILLC’s product/patent coverage may be accessed at www.onsemi.com/site/pdf/Patent−Marking.pdf. SCILLC reserves the right to make changes without further notice to any products herein. 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