POWER DRIVER FOR STEPPER MOTORS INTEGRATED CIRCUITS TMC262 DATASHEET Universal, cost-effective stepper driver for two-phase bipolar motors with state-of-the-art features. External MOSFETs fit different motor sizes. With Step/Dir Interface and SPI. APPLICATIONS FEATURES AND Textile, Sewing Machines Factory Automation Lab Automation Liquid Handling Medical Office Automation Printer and Scanner CCTV, Security ATM, Cash recycler POS Pumps and Valves Heliostat Controller CNC Machines BENEFITS High Current up to 8A Motor current using external (N&P) MOSFETs. DESCRIPTION The TMC262 driver for two-phase stepper motors offers an industry-leading feature set, including high-resolution microstepping, sensorless mechanical load measurement, load-adaptive power optimization, and low-resonance chopper operation. Standard SPI™ and STEP/DIR interfaces simplify communication. The TMC262 drives four external N- and Pchannel dual MOSFETs for motor currents up to 8A and up to 60V. Integrated protection and diagnostic features support robust and reliable operation. High integration, high energy efficiency and small form factor enable miniaturized designs with low external component count for cost-effective and highly competitive solutions. Highest Voltage up to 60V DC operating voltage Highest Resolution up to 256 microsteps per full step Smallest Size 5x5mm QFN32 package Low Power Dissipation synchronous rectification EMI-optimized slope & current controlled gate drivers Protection & Diagnostics overcurrent, overtemperature & undervoltage short to GND, stallGuard2™ high precision sensorless motor load detection coolStep™ load dependent current control for energy savings up to 75% microPlyer™ microstep interpolation smoothness with coarse step inputs. for increased spreadCycle™ high-precision chopper for best current sine wave form and zero crossing BLOCK DIAGRAM +VM TMC262 STEP DIR CSN SCK SDI SDO Step Multiplier VCC_IO Gate driver Gate Driver Sine Table 4*256 entry SPI control, Config & Diags Protection & Diagnostics x HS S Chopper N BM Gate driver Gate Driver 2 Phase Stepper LS coolStep™ RS stallGuard2™ 2 x Current Comparator SG_TST TRINAMIC Motion Control GmbH & Co. KG Hamburg, Germany 2 x DAC RS RS TMC262 DATASHEET (V2.07 / 2013-FEB-14) 2 APPLICATION EXAMPLES: HIGH POWER – SMALL SIZE The TMC262 scores with its high power density and a versatility that covers a wide spectrum of applications and motor sizes, all while keeping costs down. Extensive support at the chip, board, and software levels enables rapid design cycles and fast time-to-market with competitive products. High energy efficiency from TRINAMIC’s coolStep technology delivers further cost savings in related systems such as power supplies and cooling. STEPROCKER™ The driver stage shown uses 6A-capable dual MOSFETs. All cooling requirements are satisfied by passive convection cooling. The stepRocker is supported by the motioncontrol-community, with forum, applications, schematics, open source projects, demos etc.: Layout with 6A MOSFETs TMCM-MODULE FOR NEMA 11 STEPPER MOTORS This miniaturized power stage drives up to 1.2A RMS and mounts directly on a 28mm-size motor. Tiny TSOP6 dual MOSFETs enable an ultra-compact and flexible PCB layout. Miniaturized Layout TMC262-EVAL DEVELOPMENT PLATFORM This evaluation board is a development platform for applications based on the TMC262. The board features USB and RS232 interfaces for communication with control software running on a PC. External power MOSFETs support drive currents up to 6A at 40 V. The control software provides a user-friendly GUI for setting control parameters and visualizing the dynamic response of the motor. Layout for Evaluation Motor movement can be controlled through the Step and Dir interface using inputs from an external source or signals generated by the onboard microcontroller acting as a step generator. ORDER CODES Order code TMC262-LA TMC262-EVAL TMC429+26x-EVAL www.trinamic.com Description coolStep™ driver for external MOSFETs, QFN32 Evaluation board for TMC262 (RS232, USB) Chipset evaluation board for TMC429, TMC260, TMC261, TMC262, and TMC424. Size 5 x 5 mm2 10 x 16 cm2 10 x 16 cm2 TMC262 DATASHEET (V2.07 / 2013-FEB-14) 3 TABLE OF CONTENTS 1 PRINCIPLES OF OPERATION ......................... 4 1.1 1.2 1.3 1.4 2 KEY CONCEPTS ............................................... 4 CONTROL INTERFACES .................................... 5 MECHANICAL LOAD SENSING ......................... 5 CURRENT CONTROL ........................................ 5 PIN ASSIGNMENTS ........................................... 6 2.1 2.2 PACKAGE OUTLINE ......................................... 6 SIGNAL DESCRIPTIONS .................................. 6 3 INTERNAL ARCHITECTURE ............................. 8 4 STALLGUARD2 LOAD MEASUREMENT ......... 9 4.1 4.2 4.3 4.4 5 TUNING THE STALLGUARD2 THRESHOLD ......10 STALLGUARD2 MEASUREMENT FREQUENCY AND FILTERING ............................................11 DETECTING A MOTOR STALL ........................12 LIMITS OF STALLGUARD2 OPERATION .........12 COOLSTEP LOAD-ADAPTIVE CURRENT CONTROL ...........................................................13 5.1 6 TUNING COOLSTEP .......................................15 SPI INTERFACE ................................................16 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 6.10 6.11 7 BUS SIGNALS...............................................16 BUS TIMING ................................................16 BUS ARCHITECTURE .....................................17 REGISTER WRITE COMMANDS ......................18 DRIVER CONTROL REGISTER (DRVCTRL) ....19 CHOPPER CONTROL REGISTER (CHOPCONF) 21 COOLSTEP CONTROL REGISTER (SMARTEN)22 STALLGUARD2 CONTROL REGISTER (SGCSCONF) .............................................23 DRIVER CONTROL REGISTER (DRVCONF) ...24 READ RESPONSE ..........................................25 DEVICE INITIALIZATION ...............................26 STEP/DIR INTERFACE.....................................27 7.1 7.2 7.3 7.4 7.5 8 TIMING ........................................................27 MICROSTEP TABLE .......................................28 CHANGING RESOLUTION ..............................29 MICROPLYER STEP INTERPOLATOR ...............29 STANDSTILL CURRENT REDUCTION ................30 CURRENT SETTING ..........................................31 8.1 9 SENSE RESISTORS ........................................32 CHOPPER OPERATION ...................................33 9.1 9.2 10 SPREADCYCLE MODE ....................................34 CONSTANT OFF-TIME MODE ........................36 POWER MOSFET STAGE ................................38 10.1 10.2 10.3 BREAK-BEFORE-MAKE LOGIC........................38 ENN INPUT .................................................38 SLOPE CONTROL ..........................................39 www.trinamic.com 11 DIAGNOSTICS AND PROTECTION ............. 40 11.1 11.2 11.3 11.4 SHORT TO GND DETECTION ........................ 40 OPEN-LOAD DETECTION .............................. 41 OVERTEMPERATURE DETECTION ................... 41 UNDERVOLTAGE DETECTION......................... 42 12 POWER SUPPLY SEQUENCING .................... 43 13 SYSTEM CLOCK ................................................ 44 13.1 FREQUENCY SELECTION ................................ 44 14 MOSFET EXAMPLES ......................................... 45 15 EXTERNAL POWER STAGE ............................ 46 16 LAYOUT CONSIDERATIONS ......................... 48 16.1 16.2 16.3 16.4 SENSE RESISTORS........................................ 48 EXPOSED DIE PAD....................................... 48 POWER FILTERING ....................................... 48 LAYOUT EXAMPLE ........................................ 49 17 ABSOLUTE MAXIMUM RATINGS................. 50 18 ELECTRICAL CHARACTERISTICS ................. 51 18.1 18.2 19 OPERATIONAL RANGE .................................. 51 DC AND AC SPECIFICATIONS ...................... 51 PACKAGE MECHANICAL DATA .................... 55 19.1 19.2 DIMENSIONAL DRAWINGS ........................... 55 PACKAGE CODE ........................................... 55 20 DISCLAIMER ..................................................... 56 21 ESD SENSITIVE DEVICE ................................ 56 22 TABLE OF FIGURES......................................... 57 23 REVISION HISTORY ....................................... 58 24 REFERENCES ...................................................... 58 TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 1 4 Principles of Operation 0A+ High-Level Interface µC S/D MOSFET TMC262 Driver Stage SPI High-Level Interface µC SPI S N 0B+ 0B- 0A+ TMC429 Motion Controller for up to 3 Motors 0A- S/D TMC262 MOSFET Driver Stage 0A- S N 0B+ 0B- SPI Figure 1.1 Applications block diagrams The TMC262 motor driver is the intelligence between a motion controller and the power MOSFETs for driving a two-phase stepper motor, as shown in Figure 1.1 Following power-up, an embedded microcontroller initializes the driver by sending commands over an SPI bus to write control parameters and mode bits in the TMC262. The microcontroller may implement the motion-control function as shown in the upper part of the figure, or it may send commands to a dedicated motion controller chip such as TRINAMIC’s TMC429 as shown in the lower part. The motion controller can control the motor position by sending pulses on the STEP signal while indicating the direction on the DIR signal. The TMC262 has a microstep counter and sine table to convert these signals into the coil currents which control the position of the motor. If the microcontroller implements the motion-control function, it can write values for the coil currents directly to the TMC262 over the SPI interface, in which case the STEP/DIR interface may be disabled. This mode of operation requires software to track the motor position and reference a sine table to calculate the coil currents. To optimize power consumption and heat dissipation, software may also adjust coolStep and stallGuard2 parameters in real-time, for example to implement different tradeoffs between speed and power consumption in different modes of operation. The motion control function is a hard real-time task which may be a burden to implement reliably alongside other tasks on the embedded microcontroller. By offloading the motion-control function to the TMC429, up to three motors can be operated reliably with very little demand for service from the microcontroller. Software only needs to send target positions, and the TMC429 generates precisely timed step pulses. Software retains full control over both the TMC262 and TMC429 through the SPI bus. 1.1 Key Concepts The TMC262 motor driver implements several advanced patented features which are exclusive to TRINAMIC products. These features contribute toward greater precision, greater energy efficiency, higher reliability, smoother motion, and cooler operation in many stepper motor applications. stallGuard2™ High-precision load measurement using the back EMF on the coils coolStep™ Load-adaptive current control which reduces energy consumption by as much as 75% spreadCycle™ High-precision chopper algorithm available as an alternative to the traditional constant off-time algorithm microPlyer™ Microstep interpolator for obtaining increased smoothness of microstepping over a STEP/DIR interface www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 5 In addition to these performance enhancements, TRINAMIC motor drivers also offer safeguards to detect and protect against shorted outputs, open-circuit output, overtemperature, and undervoltage conditions for enhancing safety and recovery from equipment malfunctions. 1.2 Control Interfaces There are two control interfaces from the motion controller to the motor driver: the SPI serial interface and the STEP/DIR interface. The SPI interface is used to write control information to the chip and read back status information. This interface must be used to initialize parameters and modes necessary to enable driving the motor. This interface may also be used for directly setting the currents flowing through the motor coils, as an alternative to stepping the motor using the STEP and DIR signals, so the motor can be controlled through the SPI interface alone. The STEP/DIR interface is a traditional motor control interface available for adapting existing designs to use TRINAMIC motor drivers. Using only the SPI interface requires slightly more CPU overhead to look up the sine tables and send out new current values for the coils. 1.2.1 SPI Interface The SPI interface is a bit-serial interface synchronous to a bus clock. For every bit sent from the bus master to the bus slave, another bit is sent simultaneously from the slave to the master. Communication between an SPI master and the TMC262 slave always consists of sending one 20-bit command word and receiving one 20-bit status word. The SPI command rate typically corresponds to the microstep rate at low velocities. At high velocities, the rate may be limited by CPU bandwidth to 10-100 thousand commands per second, so the application may need to change to fullstep resolution. 1.2.2 STEP/DIR Interface The STEP/DIR interface is enabled by default. Active edges on the STEP input can be rising edges or both rising and falling edges, as controlled by another mode bit (DEDGE). Using both edges cuts the toggle rate of the STEP signal in half, which is useful for communication over slow interfaces such as optically isolated interfaces. On each active edge, the state sampled from the DIR input determines whether to step forward or back. Each step can be a fullstep or a microstep, in which there are 2, 4, 8, 16, 32, 64, 128, or 256 microsteps per fullstep. During microstepping, a low state on DIR increases the microstep counter and a high decreases the counter by an amount controlled by the microstep resolution. An internal table translates the counter value into the sine and cosine values which control the motor current for microstepping. 1.3 Mechanical Load Sensing The TMC262 provides stallGuard2 high-resolution load measurement for determining the mechanical load on the motor by measuring the back EMF. In addition to detecting when a motor stalls, this feature can be used for homing to a mechanical stop without a limit switch or proximity detector. The coolStep power-saving mechanism uses stallGuard2 to reduce the motor current to the minimum motor current required to meet the actual load placed on the motor. 1.4 Current Control Current into the motor coils is controlled using a cycle-by-cycle chopper mode. Two chopper modes are available: a traditional constant off-time mode and the new spreadCycle mode. spreadCycle mode offers smoother operation and greater power efficiency over a wide range of speed and load. www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 2 6 Pin Assignments TST_ANA VS 7 14 15 16 CSN ENN CLK SDI 13 GND SDO 12 SCK 11 5VOUT 8 10 24 SG_TST 6 9 23 GNDP TMC 262-LA VHS HB1 22 VCC_IO 25 HB2 21 DIR 26 BMB2 20 STEP 27 5 SRA 28 BMB1 19 4 LA2 29 LB1 18 3 BMA2 LA1 30 LB2 17 HA2 BMA1 31 2 HA1 32 1 GND TST_MODE 2.1 Package Outline SRB Top view Figure 2.1 TMC262 pin assignments 2.2 Signal Descriptions Pin GND HA1 HA2 HB1 HB2 BMA1 BMA2 BMB1 BMB2 LA1 LA2 LB1 LB2 SRA SRB 5VOUT Number 1 13 2 3 23 22 5 4 20 21 6 7 19 18 8 17 9 www.trinamic.com Type Function Digital and analog low power GND O (VS) High side P-channel driver output. Becomes driven to VHS to switch on MOSFET. I (VS) Sensing input for bridge outputs. Used for short to GND protection. May be tied to VS if unused. O 5V Low side MOSFET driver output. Becomes driven to 5VOUT to switch on MOSFET. AI Sense resistor input of chopper driver. Output of internal 5V linear regulator. This voltage is used to supply the low side drivers and internal analog circuitry. An external capacitor to GND close to the pin is required. Place the capacitor near to pin 9 and pin 13. 470nF ceramic are sufficient for most applications, an additional tantalum capacitor (10µF or more) improves performance with high gate charge MOSFETs. TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) Pin SDO SDI Number 10 11 Type DO VIO DI VIO SCK 12 DI VIO CSN ENN CLK 14 15 16 DI VIO DI VIO DI VIO VHS VS TST_ANA SG_TST GNDP VCC_IO 24 25 26 27 28 29 AO VIO DO VIO DIR 30 DI VIO STEP TST_MODE 31 32 DI VIO DI VIO www.trinamic.com Function Data output of SPI interface (Tristate) Data input of SPI interface (Scan test input in test mode) Serial clock input of SPI interface (Scan test shift enable input in test mode) Chip select input of SPI interface Enable not input for drivers. Switches off all MOSFETs. Clock input for all internal operations. Tie low to use internal oscillator. A high signal disables the internal oscillator until power down. High side supply voltage (motor supply voltage - 10V) Motor supply voltage Analog mode test output. Leave open for normal operation. stallGuard2™ output. Signals motor stall (high active). Power GND for MOSFET drivers. Connect directly to GND Input / output supply voltage VIO for all digital pins. Tie to digital logic supply voltage. Allows operation in 3.3V and 5V systems. Direction input. Is sampled upon detection of a step to determine stepping direction. An internal glitch filter for 60ns is provided. Step input. An internal glitch filter for 60ns is provided. Test mode input. Puts IC into test mode. Tie to GND for normal operation. 7 TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 3 8 Internal Architecture Figure 3.1 shows the internal architecture of the TMC262. +VM 9-59V VHS 220n 16V 100n VS TMC262 +VCC VCC_IO 3.3V or 5V VM-10V linear regulator OSC 15MHz D 100n 5V linear regulator 5VOUT 5V supply 470nF Provide sufficient filtering capacity near bridge transistors (electrolyt capacitors and ceramic capacitors) slope HS VHS 8-20MHz CLK Clock selector D P-Gate drivers ENABLE STEP step & dir (optional) DIR Step & Direction interface D D Phase polarity ENABLE CSN SCK SPI SDI SDO D N-Gate drivers 9 M U X D D Break before make SPI interface 9 D slope LS +5V DAC SG_TST S HA2 G S G P D BMA1 P D BMA2 motor coil A D LA2 LA1 D N G N G S S SRA RSENSE 100mΩ for 2.8A peak (resp. 1.5A peak) RSENSE 100mΩ for 2.8A peak (resp. 1.5A peak) 10R optional input protection resistors against inductive sparks upon motor cable break DAC slope LS +5V SRB 10R D CoolStep Energy efficiency stallGuard output Short to GND detectors HA1 VREF Digital control D Chopper logic 0.16V 0.30V TEST_SE SIN & COS VSENSE Step multiply 16 à 256 Sine wave 1024 entry +VM CLK D stallGuard 2 Protection & Diagnostics N-Gate drivers BACK EMF Phase polarity Chopper logic SHORT TO GND Break before make Short to GND detectors LB1 S G LB2 S G N D motor coil B BMB2 BMB1 D ENABLE Temperature sensor 100°C, 150°C P-Gate drivers slope HS VHS DIE PAD GND N D HB2 D P G P G S S HB1 +VM TEST_ANA Figure 3.1 TMC262 block diagram Prominent features include: Oscillator and clock selector Step and direction interface SPI interface Multiplexer Multipliers DACs and comparators Break-before-make and gate drivers On-chip voltage regulators www.trinamic.com provides the system clock from the on-chip oscillator or an external source. uses a microstep counter and sine table to generate target currents for the coils. receives commands that directly set the coil current values. selects either the output of the sine table or the SPI interface for controlling the current into the motor coils. scales down the currents to both coils when the currents are greater than those required by the load on the motor or as set by the CS current scale parameter. converts the digital current values to analog signals that are compared with the voltages on the sense resistors. Comparator outputs terminate chopper drive phases when target currents are reached. ensure non-overlapping pulses, boost pulse voltage, and control pulse slope to the gates of the power MOSFETs. provide high-side voltage for P-channel MOSFET gate drivers and supply voltage for on-chip analog and digital circuits. TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 4 9 stallGuard2 Load Measurement stallGuard2 provides an accurate measurement of the load on the motor. It can be used for stall detection as well as other uses at loads below those which stall the motor, such as coolStep loadadaptive current reduction. (stallGuard2 is a more precise evolution of the earlier stallGuard technology.) The stallGuard2 measurement value changes linearly over a wide range of load, velocity, and current settings, as shown in Figure 4.1. At maximum motor load, the value goes to zero or near to zero. This corresponds to a load angle of 90° between the magnetic field of the coils and magnets in the rotor. This also is the most energy-efficient point of operation for the motor. 1000 stallGuard2 reading 900 Start value depends on motor and operating conditions 800 700 600 stallGuard value reaches zero and indicates danger of stall. This point is set by stallGuard threshold value SGT. 500 400 Motor stalls above this point. Load angle exceeds 90° and available torque sinks. 300 200 100 0 10 20 30 40 50 60 70 80 90 100 motor load (% max. torque) Figure 4.1 stallGuard2 load measurement SG as a function of load Two parameters control stallGuard2 and one status value is returned. Parameter SGT SFILT Description 7-bit signed integer that sets the stallGuard2 threshold level for asserting the SG_TST output and sets the optimum measurement range for readout. Negative values increase sensitivity, and positive values reduce sensitivity so more torque is required to indicate a stall. Zero is a good starting value. Operating at values below 10 is not recommended. Mode bit which enables the stallGuard2 filter for more precision. If set, reduces the measurement frequency to one measurement per four fullsteps. If cleared, no filtering is performed. Filtering compensates for mechanical asymmetries in the construction of the motor, but at the expense of response time. Unfiltered operation is recommended for rapid stall detection. Filtered operation is recommended for more precise load measurement. www.trinamic.com Setting 0 Comment indifferent value +1… +63 less sensitivity -1… -64 higher sensitivity 0 1 standard mode filtered mode TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) Status word SG Description 10-bit unsigned integer stallGuard2 measurement value. A higher value indicates lower mechanical load. A lower value indicates a higher load and therefore a higher load angle. For stall detection, adjust SGT to return an SG value of 0 or slightly higher upon maximum motor load before stall. 10 Range 0… 1023 Comment 0: highest load low value: high load high value: less load 4.1 Tuning the stallGuard2 Threshold Due to the dependency of the stallGuard2 value SG from motor-specific characteristics and applicationspecific demands on load and velocity the easiest way to tune the stallGuard2 threshold SGT for a specific motor type and operating conditions is interactive tuning in the actual application. The procedure is: 1. 2. 3. Operate the motor at a reasonable velocity for your application and monitor SG. Apply slowly increasing mechanical load to the motor. If the motor stalls before SG reaches zero, decrease SGT. If SG reaches zero before the motor stalls, increase SGT. A good SGT starting value is zero. SGT is signed, so it can have negative or positive values. The optimum setting is reached when SG is between 0 and 400 at increasing load shortly before the motor stalls, and SG increases by 100 or more without load. SGT in most cases can be tuned together with the motion velocity in a way that SG goes to zero when the motor stalls and the stall output SG_TST is asserted. This indicates that a step has been lost. The system clock frequency affects SG. An external crystal-stabilized clock should be used for applications that demand the highest performance. The power supply voltage also affects SG, so tighter regulation results in more accurate values. SG measurement has a high resolution, and there are a few ways to enhance its accuracy, as described in the following sections. 4.1.1 Variable Velocity Operation Across a range of velocities, on-the-fly adjustment of the stallGuard2 threshold SGT improves the accuracy of the load measurement SG. This also improves the power reduction provided by coolStep, which is driven by SG. Linear interpolation between two SGT values optimized at different velocities is a simple algorithm for obtaining most of the benefits of on-the-fly SGT adjustment, as shown in Figure 4.2. This figure shows an optimal SGT curve in black and a two-point interpolated SGT curve in red. www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) stallGuard2 reading at no load optimum SGT setting simplified SGT setting 1000 20 900 18 800 16 700 14 600 12 500 10 400 8 300 6 200 4 100 2 0 0 50 100 150 11 200 250 lower limit for stall detection 4 RPM 300 350 400 450 back EMF reaches supply voltage 500 550 600 Motor RPM (200 FS motor) Figure 4.2 Linear interpolation for optimizing SGT with changes in velocity 4.1.2 Small Motors with High Torque Ripple and Resonance Motors with a high detent torque show an increased variation of the stallGuard2 measurement value SG with varying motor currents, especially at low currents. For these motors, the current dependency might need correction in a similar manner to velocity correction for obtaining the highest accuracy. 4.1.3 Temperature Dependence of Motor Coil Resistance Motors working over a wide temperature range may require temperature correction, because motor coil resistance increases with rising temperature. This can be corrected as a linear reduction of SG at increasing temperature, as motor efficiency is reduced. 4.1.4 Accuracy and Reproducibility of stallGuard2 Measurement In a production environment, it may be desirable to use a fixed SGT value within an application for one motor type. Most of the unit-to-unit variation in stallGuard2 measurements results from manufacturing tolerances in motor construction. The measurement error of stallGuard2 – provided that all other parameters remain stable – can be as low as: | | 4.2 stallGuard2 Measurement Frequency and Filtering The stallGuard2 measurement value SG is updated with each full step of the motor. This is enough to safely detect a stall, because a stall always means the loss of four full steps. In a practical application, especially when using coolStep, a more precise measurement might be more important than an update for each fullstep because the mechanical load never changes instantaneously from one step to the next. For these applications, the SFILT bit enables a filtering function over four load measurements. The filter should always be enabled when high-precision measurement is required. It compensates for variations in motor construction, for example due to misalignment of the phase A to phase B magnets. The filter should only be disabled when rapid response to increasing load is required, such as for stall detection at high velocity. www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 12 4.3 Detecting a Motor Stall To safely detect a motor stall, a stall threshold must be determined using a specific SGT setting. Therefore, you need to determine the maximum load the motor can drive without stalling and to monitor the SG value at this load, for example some value within the range 0 to 400. The stall threshold should be a value safely within the operating limits, to allow for parameter stray. So, your microcontroller software should set a stall threshold which is slightly higher than the minimum value seen before an actual motor stall occurs. The response at an SGT setting at or near 0 gives some idea on the quality of the signal: Check the SG value without load and with maximum load. These values should show a difference of at least 100 or a few 100, which shall be large compared to the offset. If you set the SGT value so that a reading of 0 occurs at maximum motor load, an active high stall output signal will be available at SG_TST output. 4.4 Limits of stallGuard2 Operation stallGuard2 does not operate reliably at extreme motor velocities: Very low motor velocities (for many motors, less than one revolution per second) generate a low back EMF and make the measurement unstable and dependent on environment conditions (temperature, etc.). Other conditions will also lead to extreme settings of SGT and poor response of the measurement value SG to the motor load. Very high motor velocities, in which the full sinusoidal current is not driven into the motor coils also lead to poor response. These velocities are typically characterized by the motor back EMF reaching the supply voltage. www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 5 13 coolStep Load-Adaptive Current Control coolStep allows substantial energy savings, especially for motors which see varying loads or operate at a high duty cycle. Because a stepper motor application needs to work with a torque reserve of 30% to 50%, even a constant-load application allows significant energy savings because coolStep automatically enables torque reserve when required. Reducing power consumption keeps the system cooler, increases motor life, and allows reducing cost in the power supply and cooling components. Reducing motor current by half results in reducing power by a factor of four. Energy efficiency Motor generates less heat Less cooling infrastructure Cheaper motor - power consumption decreased up to 75%. improved mechanical precision. for motor and driver. does the job. 0,9 Efficiency with coolStep 0,8 Efficiency with 50% torque reserve 0,7 0,6 0,5 Efficiency 0,4 0,3 0,2 0,1 0 0 50 100 150 200 250 300 350 Velocity [RPM] Figure 5.1 Energy efficiency example with coolStep Figure 5.1 shows the efficiency gain of a 42mm stepper motor when using coolStep compared to standard operation with 50% of torque reserve. coolStep is enabled above 60rpm in the example. coolStep is controlled by several parameters, but two are critical for understanding how it works: Parameter SEMIN SEMAX Description Range 4-bit unsigned integer that sets a lower 0… 15 threshold. If SG goes below this threshold, coolStep increases the current to both coils. The 4-bit SEMIN value is scaled by 32 to cover the lower half of the range of the 10-bit SG value. (The name of this parameter is derived from smartEnergy, which is an earlier name for coolStep.) 4-bit unsigned integer that controls an upper 0… 15 threshold. If SG is sampled equal to or above this threshold enough times, coolStep decreases the current to both coils. The upper threshold is (SEMIN + SEMAX + 1) x 32. Comment lower stallGuard threshold: SEMINx32 upper stallGuard threshold: (SEMIN+SEMAX+1)x32 Figure 5.2 shows the operating regions of coolStep. The black line represents the SG measurement value, the blue line represents the mechanical load applied to the motor, and the red line represents the current into the motor coils. When the load increases, SG falls below SEMIN, and coolStep www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 14 mechanical load stallGuard2 reading motor current increases the current. When the load decreases and SG rises above (SEMIN + SEMAX + 1) x 32 the current becomes reduced. current setting CS (upper limit) motor current reduction area SEMAX+SEMIN+1 SEMIN ½ or ¼ CS (lower limit) motor current increment area 0=maximum load load angle optimized time slow current reduction due to reduced motor load load angle optimized current increment due to increased load stall possible load angle optimized Figure 5.2 coolStep adapts motor current to the load Four more parameters control coolStep and one status value is returned: Parameter CS SEUP SEDN SEIMIN Status word SE Description Current scale. Scales both coil current values as taken from the internal sine wave table or from the SPI interface. For high precision motor operation, work with a current scaling factor in the range 16 to 31, because scaling down the current values reduces the effective microstep resolution by making microsteps coarser. This setting also controls the maximum current value set by coolStep™. Number of increments of the coil current for each occurrence of an SG measurement below the lower threshold. Number of occurrences of SG measurements above the upper threshold before the coil current is decremented. Range Comment 0… 31 scaling factor: 1/32, 2/32, … 32/32 0… 3 step width is: 1, 2, 4, 8 0… 3 number of stallGuard measurements per decrement: 32, 8, 2, 1 Minimum motor current: 1/2 of CS 1/4 of CS Comment Actual motor current scaling factor set by coolStep: 1/32, 2/32, … 32/32 Mode bit that controls the lower limit for scaling the coil current. If the bit is set, the limit is ¼ 0 CS. If the bit is clear, the limit is ½ CS. 1 Description Range 5-bit unsigned integer reporting the actual 0… 31 current scaling value determined by coolStep. This value is biased by 1 and divided by 32, so the range is 1/32 to 32/32. The value will not be greater than the value of CS or lower than either ¼ CS or ½ CS depending on the setting of SEIMIN. www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 15 5.1 Tuning coolStep Before tuning coolStep, first tune the stallGuard2 threshold level SGT, which affects the range of the load measurement value SG. coolStep uses SG to operate the motor near the optimum load angle of +90°. The current increment speed is specified in SEUP, and the current decrement speed is specified in SEDN. They can be tuned separately because they are triggered by different events that may need different responses. The encodings for these parameters allow the coil currents to be increased much more quickly than decreased, because crossing the lower threshold is a more serious event that may require a faster response. If the response is too slow, the motor may stall. In contrast, a slow response to crossing the upper threshold does not risk anything more serious than missing an opportunity to save power. coolStep operates between limits controlled by the current scale parameter CS and the SEIMIN bit. 5.1.1 Response Time For fast response to increasing motor load, use a high current increment step SEUP. If the motor load changes slowly, a lower current increment step can be used to avoid motor current oscillations. If the filter controlled by SFILT is enabled, the measurement rate and regulation speed are cut by a factor of four. 5.1.2 Low Velocity and Standby Operation Because stallGuard2 is not able to measure the motor load in standstill and at very low RPM, the current at low velocities should be set to an application-specific default value and combined with standstill current reduction settings programmed through the SPI interface. www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 6 16 SPI Interface The TMC262 requires setting configuration parameters and mode bits through the SPI interface before the motor can be driven. The SPI interface also allows reading back status values and bits. 6.1 Bus Signals The SPI bus on the TMC262 has four signals: SCK SDI SDO CSN bus clock input serial data input serial data output chip select input (active low) The slave is enabled for an SPI transaction by a low on the chip select input CSN. Bit transfer is synchronous to the bus clock SCK, with the slave latching the data from SDI on the rising edge of SCK and driving data to SDO following the falling edge. The most significant bit is sent first. A minimum of 20 SCK clock cycles is required for a bus transaction with the TMC262. If more than 20 clocks are driven, the additional bits shifted into SDI are shifted out on SDO after a 20-clock delay through an internal shift register. This can be used for daisy chaining multiple chips. CSN must be low during the whole bus transaction. When CSN goes high, the contents of the internal shift register are latched into the internal control register and recognized as a command from the master to the slave. If more than 20 bits are sent, only the last 20 bits received before the rising edge of CSN are recognized as the command. 6.2 Bus Timing SPI interface is synchronized to the internal system clock, which limits the SPI bus clock SCK to half of the system clock frequency. If the system clock is based on the on-chip oscillator, an additional 10% safety margin must be used to ensure reliable data transmission. All SPI inputs as well as the ENN input are internally filtered to avoid triggering on pulses shorter than 20ns. Figure 6.1 shows the timing parameters of an SPI bus transaction, and the table below specifies their values. CSN tCC tCL tCH tCH tCC SCK tDU SDI bit19 tDH bit18 bit0 tDO SDO Figure 6.1 SPI Timing www.trinamic.com tZC bit19 bit18 bit0 TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 17 AC-Characteristics clock period is tCLK SPI Interface Timing Parameter SCK valid before or after change of CSN CSN high time Symbol Conditions Min tCC Typ Max Unit 10 ns *) fSCK Min time is for synchronous CLK with SCK high one t before CSN high only *) Min time is for synchronous CLK only *) Min time is for synchronous CLK only Assumes minimum OSC frequency fSCK Assumes synchronous CLK tCSH tCLK >2tCLK +10 ns tCLK >tCLK+10 ns tCLK >tCLK+10 ns CH SCK low time tCL SCK high time tCH SCK frequency using internal clock SCK frequency using external 16MHz clock SDI setup time before rising edge of SCK SDI hold time after rising edge of SCK Data out valid time after falling SCK clock edge SDI, SCK, and CSN filter delay time 4 MHz 8 MHz tDU 10 ns tDH 10 ns tDO No capacitive load on SDO tFILT Rising and falling edge 12 20 tFILT+5 ns 30 ns 6.3 Bus Architecture SPI slaves can be chained and used with a single chip select line. If slaves are chained, they behave like a long shift register. For example, a chain of two motor drivers requires 40 bits to be sent. The last bits shifted to each register in the chain are loaded into an internal register on the rising edge of the CSN input. For example, 24 or 32 bits can be sent to a single motor driver, but it latches just the last 20 bits received before CSN goes high. Mechanical Feedback or virtual stop switch +VM Real time Step/Dir interface TMC429 triple stepper motor controller nSCS_C SCK_C SDI_C SDOZ_C nINT SPI to master Interrupt controller Reference switch processing ntro n co Motio 3x linear RAMP generator Step & Direction pulse generation Position comparator Microstep table CLK Realtime event trigger l TMC262 STEP D1 (SCK_S) Output select SPI or Step & Dir M o to VCC_IO S1 (SDO_S) S2 (nSCS_S) D2 (SDI_S) S3 (nSCS_2) D3 (nSCS_3) DIR Driver 2 Driver 3 Serial driver interface CSN SCK SDI SDO Step Multiplier 3 x REF_L, REF_R Protection & Diagnostics POSCOMP x Sine Table 4*256 entry SPI control, Config & Diags er r Driv Gate driver Gate Driver S Gate driver Gate Driver System interfacing User CPU ntro m co Syste RS stallGuard2™ 2 x Current Comparator 2 x DAC SG_TST Third driver and motor l Figure 6.2 Interfaces to a TMC429 motion controller chip and a TMC262 motor driver www.trinamic.com 2 Phase Stepper LS coolStep™ Virtual stop switch Configuration and diagnostics SPI(TM) N BM Second driver and motor Motion command SPI(TM) HS Chopper RS RS TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 18 Figure 6.2 shows the interfaces in a typical application. The SPI bus is used by an embedded MCU to initialize the control registers of both a motion controller and one or more motor drivers. STEP/DIR interfaces are used between the motion controller and the motor drivers. 6.4 Register Write Commands An SPI bus transaction to the TMC262 is a write command to one of the five write-only registers that hold configuration parameters and mode bits: Register Driver Control Register (DRVCTRL) Chopper Configuration Register (CHOPCONF) coolStep Configuration Register (SMARTEN) stallGuard2 Configuration Register (SGCSCONF) Driver Configuration Register (DRVCONF) Description The DRVCTRL register has different formats for controlling the interface to the motion controller depending on whether or not the STEP/DIR interface is enabled. The CHOPCONF register holds chopper parameters and mode bits. The SMARTEN register holds coolStep parameters and a mode bit. (smartEnergy is an earlier name for coolStep.) The SGCSCONF register holds stallGuard2 parameters and a mode bit. The DRVCONF register holds parameters and mode bits used to control the power MOSFETs and the protection circuitry. It also holds the SDOFF bit which controls the STEP/DIR interface and the RDSEL parameter which controls the contents of the response returned in an SPI transaction In the following sections, multibit binary values are prefixed with a % sign, for example %0111. 6.4.1 Write Command Overview The table below shows the formats for the five register write commands. Bits 19, 18, and sometimes 17 select the register being written, as shown in bold. The DRVCTRL register has two formats, as selected by the SDOFF bit. Bits shown as 0 must always be written as 0, and bits shown as 1 must always be written with 1. Detailed descriptions of each parameter and mode bit are given in the following sections. Register/ DRVCTRL DRVCTRL Bit (SDOFF=1) (SDOFF=0) 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 0 0 PHA CA7 CA6 CA5 CA4 CA3 CA2 CA1 CA0 PHB CB7 CB6 CB5 CB4 CB3 CB2 CB1 CB0 0 0 0 0 0 0 0 0 0 0 INTPOL DEDGE 0 0 0 0 MRES3 MRES2 MRES1 MRES0 www.trinamic.com CHOPCONF SMARTEN SGCSCONF DRVCONF 1 0 0 TBL1 TBL0 CHM RNDTF HDEC1 HDEC0 HEND3 HEND2 HEND1 HEND0 HSTRT2 HSTRT1 HSTRT0 TOFF3 TOFF2 TOFF1 TOFF0 1 0 1 0 SEIMIN SEDN1 SEDN0 0 SEMAX3 SEMAX2 SEMAX1 SEMAX0 0 SEUP1 SEUP0 0 SEMIN3 SEMIN2 SEMIN1 SEMIN0 1 1 0 SFILT 0 SGT6 SGT5 SGT4 SGT3 SGT2 SGT1 SGT0 0 0 0 CS4 CS3 CS2 CS1 CS0 1 1 1 TST SLPH1 SLPH0 SLPL1 SLPL0 0 DISS2G TS2G1 TS2G0 SDOFF VSENSE RDSEL1 RDSEL0 0 0 0 0 TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 19 6.4.2 Read Response Overview The table below shows the formats for the read response. The RDSEL parameter in the DRVCONF register selects the format of the read response. Bit RDSEL=%00 RDSEL=%01 RDSEL=%10 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 MSTEP9 MSTEP8 MSTEP7 MSTEP6 MSTEP5 MSTEP4 MSTEP3 MSTEP2 MSTEP1 MSTEP0 STST OLB OLA S2GB S2GA OTPW OT SG SG9 SG8 SG7 SG6 SG5 SG4 SG3 SG2 SG1 SG0 - SG9 SG8 SG7 SG6 SG5 SE4 SE3 SE2 SE1 SE0 - 6.5 Driver Control Register (DRVCTRL) The format of the DRVCTRL register depends on the state of the SDOFF mode bit. SPI Mode SDOFF bit is set, the STEP/DIR interface is disabled, and DRVCTRL is the interface for specifying the currents through each coil. STEP/DIR Mode SDOFF bit is clear, the STEP/DIR interface is enabled, and DRVCTRL is a configuration register for the STEP/DIR interface. 6.5.1 DRVCTRL Register in SPI Mode DRVCTRL Driver Control in SPI Mode (SDOFF=1) Bit 19 18 17 Name 0 0 PHA Function Register address bit Register address bit Polarity A CA7 CA6 CA5 CA4 CA3 CA2 CA1 CA0 Current A MSB 16 15 14 13 12 11 10 9 www.trinamic.com Current A LSB Comment Sign of current flow through coil A: 0: Current flows from OA1 pins to OA2 pins. 1: Current flows from OA2 pins to OA1 pins. Magnitude of current flow through coil A. The range is 0 to 248, if hysteresis or offset are used up to their full extent. The resulting value after applying hysteresis or offset must not exceed 255. TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 20 DRVCTRL Driver Control in SPI Mode (SDOFF=1) Bit 8 Name PHB Function Polarity B CB7 CB6 CB5 CB4 CB3 CB2 CB1 CB0 Current B MSB 7 6 5 4 3 2 1 0 Comment Sign of current flow through coil B: 0: Current flows from OB1 pins to OB2 pins. 1: Current flows from OB2 pins to OB1 pins. Magnitude of current flow through coil B. The range is 0 to 248, if hysteresis or offset are used up to their full extent. The resulting value after applying hysteresis or offset must not exceed 255. Current B LSB 6.5.2 DRVCTRL Register in STEP/DIR Mode DRVCTRL Driver Control in STEP/DIR Mode (SDOFF=0) Bit 19 18 17 16 15 14 13 12 11 10 9 Name 0 0 0 0 0 0 0 0 0 0 INTPOL 8 DEDGE Function Register address bit Register address bit Reserved Reserved Reserved Reserved Reserved Reserved Reserved Reserved Enable STEP interpolation Enable double edge STEP pulses 7 6 5 4 3 2 1 0 0 0 0 0 MRES3 MRES2 MRES1 MRES0 www.trinamic.com Reserved Reserved Reserved Reserved Microstep resolution for STEP/DIR mode Comment 0: Disable STEP pulse interpolation. 1: Enable STEP pulse multiplication by 16. 0: Rising STEP pulse edge is active, falling edge is inactive. 1: Both rising and falling STEP pulse edges are active. Microsteps per 90°: %0000: 256 %0001: 128 %0010: 64 %0011: 32 %0100: 16 %0101: 8 %0110: 4 %0111: 2 (halfstep) %1000: 1 (fullstep) TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 21 6.6 Chopper Control Register (CHOPCONF) CHOPCONF Chopper Configuration Bit 19 18 17 16 15 Name 1 0 0 TBL1 TBL0 Function Register address bit Register address bit Register address bit Blanking time CHM Chopper mode 14 Comment Blanking time interval, in system clock periods: %00: 16 %01: 24 %10: 36 %11: 54 This mode bit affects the interpretation of the HDEC, HEND, and HSTRT parameters shown below. 0 Standard mode (spreadCycle) 1 13 RNDTF Random TOFF time 12 11 HDEC1 HDEC0 Hysteresis decrement interval or Fast decay mode 10 9 HEND3 HEND2 Hysteresis end (low) value or Sine wave offset 8 7 HEND1 HEND0 6 5 4 HSTRT2 HSTRT1 HSTRT0 Hysteresis start value or Fast decay time setting Constant tOFF with fast decay time. Fast decay time is also terminated when the negative nominal current is reached. Fast decay is after on time. Enable randomizing the slow decay phase duration: 0: Chopper off time is fixed as set by bits tOFF 1: Random mode, tOFF is random modulated by dNCLK= -12 … +3 clocks. CHM=0 Hysteresis decrement period setting, in system clock periods: %00: 16 %01: 32 %10: 48 %11: 64 CHM=1 HDEC1=0: current comparator can terminate the fast decay phase before timer expires. HDEC1=1: only the timer terminates the fast decay phase. HDEC0: MSB of fast decay time setting. CHM=0 %0000 … %1111: Hysteresis is -3, -2, -1, 0, 1, …, 12 (1/512 of this setting adds to current setting) This is the hysteresis value which becomes used for the hysteresis chopper. CHM=1 %0000 … %1111: Offset is -3, -2, -1, 0, 1, …, 12 This is the sine wave offset and 1/512 of the value becomes added to the absolute value of each sine wave entry. CHM=0 CHM=1 www.trinamic.com Hysteresis start offset from HEND: %000: 1 %100: 5 %001: 2 %101: 6 %010: 3 %110: 7 %011: 4 %111: 8 Effective: HEND+HSTRT must be ≤ 15 Three least-significant bits of the duration of the fast decay phase. The MSB is HDEC0. Fast decay time is a multiple of system clock periods: NCLK= 32 x (HDEC0+HSTRT) TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) CHOPCONF Chopper Configuration Bit 3 2 1 0 Function Off time/MOSFET disable Name TOFF3 TOFF2 TOFF1 TOFF0 22 Comment Duration of slow decay phase. If TOFF is 0, the MOSFETs are shut off. If TOFF is nonzero, slow decay time is a multiple of system clock periods: NCLK= 12 + (32 x TOFF) (Minimum time is 64clocks.) %0000: Driver disable, all bridges off %0001: 1 (use with TBL of minimum 24 clocks) %0010 … %1111: 2 … 15 6.7 coolStep Control Register (SMARTEN) SMARTEN coolStep Configuration Bit 19 18 17 16 15 Name 1 0 1 0 SEIMIN 14 13 SEDN1 SEDN0 Function Register address bit Register address bit Register address bit Reserved Minimum coolStep current Current decrement speed 12 11 10 9 8 7 6 5 0 SEMAX3 SEMAX2 SEMAX1 SEMAX0 0 SEUP1 SEUP0 Reserved Upper coolStep threshold as an offset from the lower threshold Reserved Current increment size 4 3 2 1 0 0 SEMIN3 SEMIN2 SEMIN1 SEMIN0 Reserved Lower coolStep threshold/coolStep disable www.trinamic.com Comment 0: ½ CS current setting 1: ¼ CS current setting Number of times that the stallGuard2 value must be sampled equal to or above the upper threshold for each decrement of the coil current: %00: 32 %01: 8 %10: 2 %11: 1 If the stallGuard2 measurement value SG is sampled equal to or above (SEMIN+SEMAX+1) x 32 enough times, then the coil current scaling factor is decremented. Number of current increment steps for each time that the stallGuard2 value SG is sampled below the lower threshold: %00: 1 %01: 2 %10: 4 %11: 8 If SEMIN is 0, coolStep is disabled. If SEMIN is nonzero and the stallGuard2 value SG falls below SEMIN x 32, the coolStep current scaling factor is increased. TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 23 6.8 stallGuard2 Control Register (SGCSCONF) SGCSCONF stallGuard2™ and Current Setting Bit 19 18 17 16 Name 1 1 0 SFILT Function Register address bit Register address bit Register address bit stallGuard2 filter enable 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 0 SGT6 SGT5 SGT4 SGT3 SGT2 SGT1 SGT0 0 0 0 CS4 CS3 CS2 CS1 CS0 Reserved stallGuard2 threshold value www.trinamic.com Reserved Reserved Reserved Current scale (scales digital currents A and B) Comment 0: Standard mode, fastest response time. 1: Filtered mode, updated once for each four fullsteps to compensate for variation in motor construction, highest accuracy. The stallGuard2 threshold value controls the optimum measurement range for readout and stall indicator output (SG_TST). A lower value results in a higher sensitivity and less torque is required to indicate a stall. The value is a two’s complement signed integer. Values below -10 are not recommended. Range: -64 to +63 Current scaling for SPI and STEP/DIR operation. %00000 … %11111: 1/32, 2/32, 3/32, … 32/32 This value is biased by 1 and divided by 32, so the range is 1/32 to 32/32. Example: CS=20 is 21/32 current. TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 24 6.9 Driver Control Register (DRVCONF) DRVCONF Driver Configuration Bit Name Function 19 18 17 16 1 1 1 TST Register address bit Register address bit Register address bit Reserved TEST mode 15 14 SLPH1 SLPH0 Slope control, high side 13 12 SLPL1 SLPL0 Slope side 11 10 0 DISS2G 9 8 TS2G1 TS2G0 Reserved Short to GND protection disable Short to GND detection timer 7 SDOFF STEP/DIR interface disable 6 VSENSE Sense resistor voltage-based current scaling 5 4 RDSEL1 RDSEL0 Select value for read out (RD bits) 3 2 1 0 0 0 0 0 Reserved Reserved Reserved Reserved www.trinamic.com control, Comment low Must be cleared for normal operation. When set, the SG_TST output exposes digital test values, and the TEST_ANA output exposes analog test values. Test value selection is controlled by SGT1 and SGT0: TEST_ANA: %00: anatest_2vth, %01: anatest_dac_out, %10: anatest_vdd_half. SG_TST: %00: comp_A, %01: comp_B, %10: CLK, %11: on_state_xy %00: Minimum %01: Minimum temperature compensation mode. %10: Medium temperature compensation mode. %11: Maximum In temperature compensated mode (tc), the MOSFET gate driver strength is increased if the overtemperature warning temperature is reached. This compensates for temperature dependency of high-side slope control. %00: Minimum. %01: Minimum. %10: Medium. %11: Maximum. 0: Short to GND protection is enabled. 1: Short to GND protection is disabled. %00: 3.2µs. %01: 1.6µs. %10: 1.2µs. %11: 0.8µs. 0: Enable STEP/DIR operation. 1: Disable STEP/DIR operation. SPI interface is used to move motor. 0: Full-scale sense resistor voltage is 305mV. 1: Full-scale sense resistor voltage is 165mV. (Full-scale refers to a current setting of 31 and a DAC value of 255.) %00 Microstep position read back %01 stallGuard2 level read back %10 stallGuard2 and coolStep current level read back %11 Reserved, do not use TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 25 6.10 Read Response For every write command sent to the motor driver, a 20-bit response is returned to the motion controller. The response has one of three formats, as selected by the RDSEL parameter in the DRVCONF register. The table below shows these formats. Software must not depend on the value of any bit shown as reserved. DRVSTATUS Read Response Bit Function Comment Microstep counter for coil A or stallGuard2 value SG9:0 or stallGuard2 value SG9:5 and coolStep value SE4:0 Microstep position in sine table for coil A in STEP/DIR mode. MSTEP9 is the Polarity bit: 0: Current flows from OA1 pins to OA2 pins. 1: Current flows from OA2 pins to OA1 pins. Standstill indicator 0: No standstill condition detected. 1: No active edge occurred on the STEP input during the last 220 system clock cycles. 0: No open load condition detected. 1: No chopper event has happened during the last period with constant coil polarity. Only a current above 1/16 of the maximum setting can clear this bit! Hint: This bit is only a status indicator. The chip takes no other action when this bit is set. False indications may occur during fast motion and at standstill. Check this bit only during slow motion. 0: No short to ground shutdown condition. 1: Short to ground shutdown condition. The short counter is incremented by each short circuit and the chopper cycle is suspended. The counter is decremented for each phase polarity change. The MOSFETs are shut off when the counter reaches 3 and remain shut off until the shutdown condition is cleared by disabling and re-enabling the driver. The shutdown condition becomes reset by deasserting the ENN input or clearing the TOFF parameter. 0: No overtemperature warning condition. 1: Warning threshold is active. 0: No overtemperature shutdown condition. 1: Overtemperature shutdown has occurred. 0: No motor stall detected. 1: stallGuard2 threshold has been reached, and the SG_TST output is driven high. Name RDSEL=%00 %01 %10 19 18 17 16 15 14 13 12 11 10 9 8 7 MSTEP9 MSTEP8 MSTEP7 MSTEP6 MSTEP5 MSTEP4 MSTEP3 MSTEP2 MSTEP1 MSTEP0 Reserved Reserved STST SG9 SG8 SG7 SG6 SG5 SG4 SG3 SG2 SG1 SG0 SG9 SG8 SG7 SG6 SG5 SE4 SE3 SE2 SE1 SE0 6 5 OLB OLA Open load indicator 4 3 S2GB S2GA Short to GND detection bits on high-side transistors 2 OTPW 1 OT 0 SG Overtemperature warning Overtemperature shutdown stallGuard2 status www.trinamic.com stallGuard2 value SG9:0. stallGuard2 value SG9:5 and the actual coolStep scaling value SE4:0. TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 26 6.11 Device Initialization The following sequence of SPI commands is an example of enabling the driver and initializing the chopper: SPI = $901B4; // Hysteresis mode SPI = $94557; // Constant toff mode SPI = $D001F; // Current setting: $d001F (max. current) SPI = $EF010; // high gate driver strength, stallGuard read, SDOFF=0 SPI = $00000; // 256 microstep setting or First test of coolStep current control: SPI = $A8202; // Enable coolStep with minimum current ¼ CS The configuration parameters should be tuned to the motor and application for optimum performance. www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 7 27 STEP/DIR Interface The STEP and DIR inputs provide a simple, standard interface compatible with many existing motion controllers. The microPlyer STEP pulse interpolator brings the smooth motor operation of highresolution microstepping to applications originally designed for coarser stepping and reduces pulse bandwidth. 7.1 Timing Figure 7.1 shows the timing parameters for the STEP and DIR signals, and the table below gives their specifications. When the DEDGE mode bit in the DRVCTRL register is set, both edges of STEP are active. If DEDGE is cleared, only rising edges are active. STEP and DIR are sampled and synchronized to the system clock. An internal analog filter removes glitches on the signals, such as those caused by long PCB traces. If the signal source is far from the chip, and especially if the signals are carried on cables, the signals should be filtered or differentially transmitted. DIR tSH tDSU tSL tDSH STEP Active edge (DEDGE=0) Active edge (DEDGE=0) Figure 7.1 STEP/DIR timing STEP and DIR Interface Timing AC-Characteristics clock period is tCLK Parameter Step frequency (at maximum microstep resolution) Symbol Conditions fSTEP DEDGE=0 DEDGE=1 fFS tSL Fullstep frequency STEP input low time STEP input high time tSH DIR to STEP setup time DIR after STEP hold time STEP and DIR spike filtering time STEP and DIR sampling relative to rising CLK input tDSU tDSH www.trinamic.com tFILTSD tSDCLKHI Rising and falling edge Before rising edge of CLK Min Typ Max ½ fCLK ¼ fCLK fCLK/512 Unit max(tFILTSD, tCLK+20) max(tFILTSD, tCLK+20) ns 20 20 36 ns ns ns ns 60 tFILTSD 85 ns TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 28 7.2 Microstep Table The internal microstep table maps the sine function from 0° to 90°, and symmetries allow mapping the sine and cosine functions from 0° to 360° with this table. The angle is encoded as a 10-bit unsigned integer MSTEP provided by the microstep counter. The size of the increment applied to the counter while microstepping through this table is controlled by the microstep resolution setting MRES in the DRVCTRL register. Depending on the DIR input, the microstep counter is increased (DIR=0) or decreased (DIR=1) by the step size with each STEP active edge. Despite many entries in the last quarter of the table being equal, the electrical angle continuously changes, because either the sine wave or cosine wave is in an area, where the current vector changes monotonically from position to position. Figure 7.2 shows the table. The largest values are 248, which leaves headroom used for adding an offset. Entry 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 0-31 1 2 4 5 7 8 10 11 13 14 16 17 19 21 22 24 25 27 28 30 31 33 34 36 37 39 40 42 43 45 46 48 32-63 49 51 52 54 55 57 58 60 61 62 64 65 67 68 70 71 73 74 76 77 79 80 81 83 84 86 87 89 90 91 93 94 64-95 96 97 98 100 101 103 104 105 107 108 109 111 112 114 115 116 118 119 120 122 123 124 126 127 128 129 131 132 133 135 136 137 96-127 138 140 141 142 143 145 146 147 148 150 151 152 153 154 156 157 158 159 160 161 163 164 165 166 167 168 169 170 172 173 174 175 128-159 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 201 202 203 204 205 206 160-191 207 207 208 209 210 211 212 212 213 214 215 215 216 217 218 218 219 220 220 221 222 223 223 224 225 225 226 226 227 228 228 229 192-223 229 230 231 231 232 232 233 233 234 234 235 235 236 236 237 237 238 238 238 239 239 240 240 240 241 241 241 242 242 242 243 243 Figure 7.2 Internal microstep table showing the first quarter of the sine wave www.trinamic.com 224-255 243 244 244 244 244 245 245 245 245 246 246 246 246 246 247 247 247 247 247 247 247 247 248 248 248 248 248 248 248 248 248 248 TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 29 7.3 Changing Resolution The application may need to change the microstepping resolution to get the best performance from the motor. For example, high-resolution microstepping may be used for precision operations on a workpiece, and then fullstepping may be used for maximum torque at maximum velocity to advance to the next workpiece. When changing to coarse resolutions like fullstepping or halfstepping, switching should occur at or near positions that correspond to steps in the lower resolution, as shown in the table below. Step Position Half step 0 Full step 0 Half step 1 Full step 1 Half step 2 Full step 2 Half step 3 Full step 3 MSTEP Value 0 128 256 384 512 640 768 896 Coil A Current 0% 70.7% 100% 70.7% 0% -70.7% -100% -70.7% Coil B Current 100% 70.7% 0% -70.7% -100% -70.7% 0% 70.7% 7.4 microPlyer Step Interpolator For each active edge on STEP, microPlyer produces 16 microsteps at 256x resolution, as shown in Figure 7.3. microPlyer is enabled by setting the INTPOL bit in the DRVCTRL register. It supports input at 16x resolution, which it transforms into 256x resolution. The step rate for each 16 microsteps is determined by measuring the time interval of the previous step period and dividing it into 16 equal parts. The maximum time between two active edges on the STEP input corresponds to 220 (roughly one million) system clock cycles, for an even distribution of 1/256 microsteps. At 16MHz system clock frequency, this results in a minimum step input frequency of 16Hz for microPlyer operation (one fullstep per second). A lower step rate causes the STST bit to be set, which indicates a standstill event. At that frequency, microsteps occur at a rate of . Active edge (DEDGE=0) Active edge (DEDGE=0) Active edge (DEDGE=0) Active edge (DEDGE=0) microPlyer only works well with a stable STEP frequency. Do not use the DEDGE option if the STEP signal does not have a 50% duty cycle. STEP interpolated microstep 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 motor angle 2^20 tCLK STANDSTILL (STST) active Figure 7.3 microPlyer microstep interpolation with rising STEP frequency www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 30 In Figure 7.3, the first STEP cycle is long enough to set the STST bit. This bit is cleared on the next STEP active edge. Then, the STEP frequency increases and after one cycle at the higher rate microPlyer increases the interpolated microstep rate. During the last cycle at the slower rate, microPlyer did not generate all 16 microsteps, so there is a small jump in motor angle between the first and second cycles at the higher rate. 7.5 Standstill current reduction When a standstill event is detected, the motor current should be reduced to save energy and reduce heat dissipation in the power MOSFET stage. This is especially true at halfstep positions, which are a worst-case condition for the driver and motor because the full energy is consumed in one bridge and one motor coil. www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 8 31 Current Setting The internal 5V supply voltage available at the pin 5VOUT is used as a reference for the coil current regulation based on the sense resistor voltage measurement. The desired maximum motor current is set by selecting an appropriate value for the sense resistor. The sense resistor voltage range can be selected by the VSENSE bit in the DRVCONF register. The low sensitivity (high sense resistor voltage, VSENSE=0) brings best and most robust current regulation, while high sensitivity (low sense resistor voltage, VSENSE=1) reduces power dissipation in the sense resistor. This setting reduces the power dissipation in the sense resistor by nearly half. After choosing the VSENSE setting and selecting the sense resistor, the currents to both coils are scaled by the 5-bit current scale parameter CS in the SGCSCONF register. The sense resistor value is chosen so that the maximum desired current (or slightly more) flows at the maximum current setting (CS = %11111). Using the internal sine wave table, which has amplitude of 248, the RMS motor current can be calculated by: √ The momentary motor current is calculated as: where: CS is the effective current scale setting as set by the CS bits and modified by coolStep. The effective value ranges from 0 to 31. VFS is the sense resistor voltage at full scale, as selected by the VSENSE control bit (refer to the electrical characteristics). CURRENTA/B is the value set by the current setting in SPI mode or the internal sine table in STEP/DIR mode. Parameter CS VSENSE Description Current scale. Scales both coil current values as taken from the internal sine wave table or from the SPI interface. For high precision motor operation, work with a current scaling factor in the range 16 to 31, because scaling down the current values reduces the effective microstep resolution by making microsteps coarser. This setting also controls the maximum current value set by coolStep™. Allows control of the sense resistor voltage range or adaptation of one electronic module to different maximum motor currents. www.trinamic.com Setting 0 … 31 Comment Scaling factor: 1/32, 2/32, … 32/32 0 310mV 1 165mV TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 32 8.1 Sense Resistors Sense resistors should be carefully selected. The full motor current flows through the sense resistors. They also see the switching spikes from the MOSFET bridges. A low-inductance type such as film or composition resistors is required to prevent spikes causing ringing on the sense voltage inputs leading to unstable measurement results. A low-inductance, low-resistance PCB layout is essential. Any common GND path for the two sense resistors must be avoided, because this would lead to coupling between the two current sense signals. A massive ground plane is best. When using high currents or long motor cables, spike damping with parallel capacitors to ground may be needed, as shown in Figure 8.1. Because the sense resistor inputs are susceptible to damage from negative overvoltages, an additional input protection resistor helps protect against a motor cable break or ringing on long motor cables. MOSFET bridge SRA 10R to 47R 470nF optional input protection resistors TMC262 RSENSE GND Power supply GND optional filter 470nF capacitors SRB no common GND path not visible to TMC262 RSENSE 10R to 47R MOSFET bridge Figure 8.1 Sense resistor grounding and protection components The sense resistor needs to be able to conduct the peak motor coil current in motor standstill conditions, unless standby power is reduced. Under normal conditions, the sense resistor sees a bit less than the coil RMS current, because no current flows through the sense resistor during the slow decay phases. The peak sense resistor power dissipation is: ( ) For high-current applications, power dissipation is halved by using the lower sense resistor voltage setting and the corresponding lower resistance value. In this case, any voltage drop in the PCB traces has a larger influence on the result. A compact power stage layout with massive ground plane is best to avoid parasitic resistance effects. www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 9 33 Chopper Operation The currents through both motor coils are controlled using choppers. The choppers work independently of each other. Figure 9.1 shows the three chopper phases: +VM +VM +VM ICOIL ICOIL ICOIL RSENSE RSENSE On Phase: current flows in direction of target current Fast Decay Phase: current flows in opposite direction of target current RSENSE Slow Decay Phase: current re-circulation Figure 9.1 Chopper phases Although the current could be regulated using only on phases and fast decay phases, insertion of the slow decay phase is important to reduce electrical losses and current ripple in the motor. The duration of the slow decay phase is specified in a control parameter and sets an upper limit on the chopper frequency. The current comparator can measure coil current during phases when the current flows through the sense resistor, but not during the slow decay phase, so the slow decay phase is terminated by a timer. The on phase is terminated by the comparator when the current through the coil reaches the target current. The fast decay phase may be terminated by either the comparator or another timer. When the coil current is switched, spikes at the sense resistors occur due to charging and discharging parasitic capacitances. During this time, typically one or two microseconds, the current cannot be measured. Blanking is the time when the input to the comparator is masked to block these spikes. There are two chopper modes available: a new high-performance chopper algorithm called spreadCycle and a proven constant off-time chopper mode. The constant off-time mode cycles through three phases: on, fast decay, and slow decay. The spreadCycle mode cycles through four phases: on, slow decay, fast decay, and a second slow decay. Three parameters are used for controlling both chopper modes: Parameter TOFF Description Setting Off time. This setting controls the duration of the 0 slow decay time and limits the maximum 1… 15 chopper frequency. For most applications an off time within the range of 5µs to 20µs will fit. If the value is 0, the MOSFETs are all shut off and the motor can freewheel. A value of 1 to 15 sets the number of system clock cycles in the slow decay phase to: The SD-Time is www.trinamic.com Comment Chopper off. Off time setting. (1 will work with minimum blank time of 24 clocks.) TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) Parameter TBL CHM Description Blanking time. This time needs to cover the switching event and the duration of the ringing on the sense resistor. For most low-current applications, a setting of 16 or 24 is good. For high-current applications, a setting of 36 or 54 may be required. Chopper mode bit 34 Setting 0 1 2 3 Comment 16 system 24 system 36 system 54 system 0 1 spreadCycle mode Constant off time mode clock clock clock clock cycles cycles cycles cycles 9.1 spreadCycle Mode The spreadCycle chopper algorithm (pat.fil.) is a precise and simple to use chopper mode which automatically determines the optimum length for the fast-decay phase. Several parameters are available to optimize the chopper to the application. Each chopper cycle is comprised of an on phase, a slow decay phase, a fast decay phase and a second slow decay phase (see Figure 9.2). The slow decay phases limit the maximum chopper frequency and are important for low motor and driver power dissipation. The hysteresis start setting limits the chopper frequency by forcing the driver to introduce a minimum amount of current ripple into the motor coils. The motor inductance limits the ability of the chopper to follow a changing motor current. The duration of the on phase and the fast decay phase must be longer than the blanking time, because the current comparator is disabled during blanking. This requirement is satisfied by choosing a positive value for the hysteresis as can be estimated by the following calculation: where: dICOILBLANK is the coil current change during the blanking time. dICOILSD is the coil current change during the slow decay time. tSD is the slow decay time. tBLANK is the blanking time (as set by TBL). VM is the motor supply voltage. ICOIL is the peak motor coil current at the maximum motor current setting CS. RCOIL and LCOIL are motor coil inductance and motor coil resistance. With this, a lower limit for the start hysteresis setting can be determined: Example: For a 42mm stepper motor with 7.5mH, 4.5Ω phase, and 1A RMS current at CS=31, i.e. 1.41A peak current, at 24V with a blank time of 1.5µs: With this, the minimum hysteresis start setting is 5.2. A value in the range 6 to 10 can be used. www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 35 An Excel spreadsheet is provided for performing these calculations. As experiments show, the setting is quite independent of the motor, because higher current motors typically also have a lower coil resistance. Choosing a medium default value for the hysteresis (for example, effective HSTRT+HEND=10) normally fits most applications. The setting can be optimized by experimenting with the motor: A too low setting will result in reduced microstep accuracy, while a too high setting will lead to more chopper noise and motor power dissipation. When measuring the sense resistor voltage in motor standstill at a medium coil current with an oscilloscope, a too low setting shows a fast decay phase not longer than the blanking time. When the fast decay time becomes slightly longer than the blanking time, the setting is optimum. You can reduce the off-time setting, if this is hard to reach. The hysteresis principle could in some cases lead to the chopper frequency becoming too low, for example when the coil resistance is high compared to the supply voltage. This is avoided by splitting the hysteresis setting into a start setting (HSTRT+HEND) and an end setting (HEND). An automatic hysteresis decrementer (HDEC) interpolates between these settings, by decrementing the hysteresis value stepwise each 16, 32, 48, or 64 system clock cycles. At the beginning of each chopper cycle, the hysteresis begins with a value which is the sum of the start and the end values (HSTRT+HEND), and decrements during the cycle, until either the chopper cycle ends or the hysteresis end value (HEND) is reached. This way, the chopper frequency is stabilized at high amplitudes and low supply voltage situations, if the frequency gets too low. This avoids the frequency reaching the audible range. I target current + hysteresis start HDEC target current + hysteresis end target current target current - hysteresis end target current - hysteresis start on sd fd sd t Figure 9.2 spreadCycle chopper mode showing the coil current during a chopper cycle Three parameters control spreadCycle mode: Parameter HSTRT Description Setting Hysteresis start setting. Please remark, that this 0… 7 value is an offset to the hysteresis end value HEND. HEND Hysteresis end setting. Sets the hysteresis end 0… 2 value after a number of decrements. Decrement interval time is controlled by HDEC. The sum HSTRT+HEND must be <16. At a current setting CS of max. 30 (amplitude reduced to 240), the sum 3 is not limited. 4… 15 www.trinamic.com Comment This setting adds to HEND. %000: 1 %100: 5 %001: 2 %101: 6 %010: 3 %110: 7 %011: 4 %111: 8 Negative HEND: -3… -1 %0000: -3 %0001: -2 %0010: -1 Zero HEND: 0 %0011: 0 Positive HEND: 1… 12 %0100: 1 %1010: 7 1100: 9 %0101: 2 %1011: 8 1101: 10 %0110: 3 %1100: 9 1110: 11 %0111: 4 %1101: 10 %1000: 5 %1110: 11 %1001: 6 %1111: 12 TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) Parameter HDEC 36 Description Setting Hysteresis decrement setting. This setting 0… 3 determines the slope of the hysteresis during on time and during fast decay time. It sets the number of system clocks for each decrement. Comment 0: fast decrement 3: very slow decrement %00: 16 %01: 32 %10: 48 %11: 64 Example: In the example above, a hysteresis start of 7 has been chosen. The hysteresis end is set to about half of this value, 3. The resulting configuration register values are: HEND=6 (sets an effective end value of 3) HSTRT=3 (sets an effective start value of hysteresis end +4) HDEC=0 (Hysteresis decrement becomes used) 9.2 Constant Off-Time Mode The classic constant off-time chopper uses a fixed-time fast decay following each on phase. While the duration of the on phase is determined by the chopper comparator, the fast decay time needs to be fast enough for the driver to follow the falling slope of the sine wave, but it should not be so long that it causes excess motor current ripple and power dissipation. This can be tuned using an oscilloscope or evaluating motor smoothness at different velocities. A good starting value is a fast decay time setting similar to the slow decay time setting. I target current + offset mean value = target current on fd on sd fd sd t Figure 9.3 Constant off-time chopper with offset showing the coil current during two cycles After tuning the fast decay time, the offset should be tuned for a smooth zero crossing. This is necessary because the fast decay phase makes the absolute value of the motor current lower than the target current (see Figure 9.4). If the zero offset is too low, the motor stands still for a short moment during current zero crossing. If it is set too high, it makes a larger microstep. Typically, a positive offset setting is required for smoothest operation. Target current I Target current I Coil current Coil current t Coil current does not have optimum shape t Target current corrected for optimum shape of coil current Figure 9.4 Zero crossing with correction using sine wave offset www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 37 Three parameters control constant off-time mode: Parameter TFD (HSTART & HDEC0) OFFSET (HEND) NCCFD (HDEC1) Description Fast decay time setting. With CHM=1, these bits control the portion of fast decay for each chopper cycle. Sine wave offset. With CHM=1, these bits control the sine wave offset. A positive offset corrects for zero crossing error. Selects usage of the current comparator for termination of the fast decay cycle. If current comparator is enabled, it terminates the fast decay cycle in case the current reaches a higher negative value than the actual positive value. Setting 0 1… 15 0…2 3 4… 15 0 1 Comment Slow decay only. Duration of fast decay phase. Negative offset: -3… -1 No offset: 0 Positive offset: 1… 12 Enable comparator termination of fast decay cycle. End by time only. 9.2.1 Random Off Time In the constant off-time chopper mode, both coil choppers run freely without synchronization. The frequency of each chopper mainly depends on the coil current and the motor coil inductance. The inductance varies with the microstep position. With some motors, a slightly audible beat can occur between the chopper frequencies when they are close together. This typically occurs at a few microstep positions within each quarter wave. This effect is usually not audible when compared to mechanical noise generated by ball bearings, etc. Another factor which can cause a similar effect is a poor layout of the sense resistor GND connections. A common cause of motor noise is a bad PCB layout causing coupling of both sense resistor voltages. To minimize the effect of a beat between both chopper frequencies, an internal random generator is provided. It modulates the slow decay time setting when switched on by the RNDTF bit. The RNDTF feature further spreads the chopper spectrum, reducing electromagnetic emission on single frequencies. Parameter RNDTF Description Setting Enables a random off-time generator, which 0 slightly modulates the off time tOFF using a 1 random polynomial. www.trinamic.com Comment Disable. Random modulation enable. TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 38 10 Power MOSFET Stage The TMC262 provides gate drivers for two full-bridges using N- and P-channel power MOSFETs. The gate current for the MOSFETs can be adapted to influence the slew rate at the coil outputs. The main features of the stage are: - 5V gate drive voltage for low-side N-MOS transistors, 8V for high-side P-MOS transistors. - The gate drivers protect the bridges actively against cross-conduction using an internal QGD protection that holds the MOSFETs safely off. - Automatic break-before-make logic minimizes dead time and diode-conduction time. - Integrated short to ground protection detects a short of the motor wires and protects the MOSFETs. The low-side gate driver is supplied by the 5VOUT pin. The low-side driver supplies 0V to the MOSFET gate to close the MOSFET, and 5VOUT to open it. The high-side gate driver voltage is supplied by the VS and the VHS pin. VHS is more negative than VS and allows opening the VS referenced high-side MOSFET. The high-side driver supplies VS to the P channel MOSFET gate to close the MOSFET and VHS to open it. The effective low-side gate voltage is roughly 5V; the effective high-side gate voltage is roughly 8V. Parameter SLPL SLPH Description Setting Low-side slope control. Controls the MOSFET gate 0… 3 driver current. Set to a value appropriate for the external MOSFET gate charge and the desired slope. High-side slope control. Controls the MOSFET 0… 3 gate driver current. Set to a value appropriate for the external MOSFET gate charge and the desired slope. Comment %00: Minimum. %01: Minimum. %10: Medium. %11: Maximum. %00: Minimum. %01: Minimum+TC. %10: Medium+TC. %11: Maximum. 10.1 Break-Before-Make Logic Each half-bridge has to be protected against cross-conduction during switching events. When switching off the low-side MOSFET, its gate first needs to be discharged before the high-side MOSFET is allowed to switch on. The same goes when switching off the high-side MOSFET and switching on the low-side MOSFET. The time for charging and discharging of the MOSFET gates depends on the MOSFET gate charge and the gate driver current set by SLPL and SLPH. The BBM (break-before-make) logic measures the gate voltage and automatically delays turning on the opposite bridge transistor until its counterpart is discharged. This way, the bridge will always switch with optimized timing independent of the slope setting. 10.2 ENN Input The MOSFETs can be completely disabled in hardware by pulling the ENN input high. This allows the motor to free-wheel. An equivalent function can be performed in software by setting the parameter TOFF to zero. The hardware disable is available for allowing the motor to be hot plugged. If a hardware disable function is not needed, tie ENN low. www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 39 10.3 Slope Control The TMC262 provides constant-current gate drivers for slope control. This allows adapting the driver strength to the drive requirements of the power MOSFETs and adjusting the output slope of the controlled gate charge and discharge. A slower slope reduces electromagnetic emissions, but it increases power dissipation in the MOSFETs. The duration of the complete switching event depends on the total gate charge of the MOSFETs. In Figure 10.1, the voltage transition of the gate-charge output (dotted line) takes place during the socalled Miller plateau. The Miller plateau results from the gate-to-drain capacitance of the MOSFET charging or discharging during switching. The datasheet for the MOSFETs typically will show a Miller plateau that only covers a part (for example, one quarter) of the complete charging/discharging event. The gate voltage level at which the Miller plateau starts depends on the threshold voltage of the MOSFET and on the actual load current. 5 25 VS 4 20 3 15 2 10 1 5 0 0 2 4 6 8 VDS – Drain to source voltage (V) VGS – Gate to source voltage (V) MOSFET gate charge vs. switching event 0 10 QMILLER QG – Total gate charge (nC) Figure 10.1 MOSFET gate charge vs. VDS for a typical MOSFET during a switching event The slope time tSLOPE can be calculated as: Where: QMILLER is the charge the MOSFET needs for the switching event. IGATE is the driver current setting. The chopper frequency is typically slightly above the audible range, around 18 kHz to 40 kHz. The lower limit for the slope is dictated by the reverse recovery time of the MOSFET internal diodes, unless additional Schottky diodes are used in parallel to the MOSFETs source-drain diode. For most applications a switching time between 100ns and 750ns is chosen. Example: A circuit using the transistor in Figure 10.1 is operated with a gate current setting of 15mA. The Miller charge of the transistor is about 2.5nC. www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 40 11 Diagnostics and Protection 11.1 Short to GND Detection The short to ground detection prevents the high-side power MOSFETs from being damaged by accidentally shorting the motor outputs to ground. It disables the MOSFETs only if a short condition persists. A temporary event like an ESD event could look like a short, but these events are filtered out by requiring the event to persist. When a short is detected, the bridge is switched off immediately, the chopper cycle on the affected coil is terminated, and the short counter is incremented. The counter is decremented for each phase polarity change. The MOSFETs are shut off when the counter reaches 3 and remain shut off until the short condition is cleared by disabling the driver and re-enabling it. The short to ground detection status is indicated by two bits: Status S2GA S2GB Description Range These bits identify a short to GND condition on 0 / 1 coil A and coil B persisting for multiple chopper cycles. The bits are cleared when the MOSFETs are disabled. Comment 0: No short condition detected. 1: Short condition detected. An overload condition on the high-side MOSFET (“short to GND”) is detected by monitoring the coil voltage during the high-side on phase. Under normal conditions, the high-side power MOSFET reaches the bridge supply voltage minus a small voltage drop during the on phase. If the bridge is overloaded, the voltage cannot rise to the detection level within the time defined by the internal detection delay setting. When an overload is detected, the bridge is switched off. The short to GND detection delay needs to be adjusted for the slope time, because it must be longer than slope, but should not be unnecessarily long. Hxy 0V VVS BMxy VVSVBMS2G Valid area 0V Short detection Driver enabled Driver off 0V tS2G Short to GND monitor phase inactive tS2G delay Figure 11.1 Short to GND detection timing www.trinamic.com Short to GND detected BM voltage monitored inactive delay Short detected TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 41 The short to ground detector is controlled by a mode bit and a parameter: Mode bit / Parameter DISS2G Description Setting Comment Short to ground detection disable bit. 0/1 TS2G This setting controls the short to GND detection 0… 3 delay time. It needs to cover the switching slope time. A higher setting reduces sensitivity to capacitive loads. 0: Short to ground detection enabled. 1: Short to ground detection disabled. %00: 3.2µs. %01: 1.6µs. %10: 1.2µs. %11: 0.8µs. 11.2 Open-Load Detection The open-load detection determines whether a motor coil has an open condition, for example due to a loose contact. When driving in fullstep mode, the open-load detection will also signal when the motor current cannot be reached within each step, for example due to a too-high motor velocity in which the back EMF voltage exceeds the supply voltage. The detection bit is only for information, and no other action is performed by the chip. Assertion of an open-load condition does not always indicate that the motor is not working properly. The bit is updated during normal operation whenever the polarity of the respective coil toggles. The open-load detection status is indicated by two bits: Status flag OLA OLB Description Range These bits indicate an open-load condition on 0 / 1 coil A and coil B. The flags become set, if no chopper event has happened during the last period with constant coil polarity. The flag is not updated with too low actual coil current below 1/16 of maximum setting. Comment 0: No open-load detected 1: Open-load detected 11.3 Overtemperature Detection The TMC262 integrates a two-level temperature sensor (100°C warning and 150°C shutdown) for diagnostics and for protection of the power MOSFETs. The temperature detector can be triggered by heat accumulation on the board, for example due to missing convection cooling. Most critical situations, in which the MOSFETs could be overheated, are avoided when using the short to ground protection. For most applications, the overtemperature warning indicates an abnormal operation situation and can be used to trigger an alarm or power-reduction measures. If continuous operation in hot environments is necessary, a more precise mechanism based on temperature measurement should be used. The thermal shutdown is strictly an emergency measure and temperature rising to the shutdown level should be prevented by design. The shutdown temperature is above the specified operating temperature range of the chip. The high-side P-channel gate drivers have a temperature dependency which can be compensated to some extent by increasing the gate driver current when the warning temperature threshold is reached. The chip automatically corrects for the temperature dependency above the warning temperature when the temperature-compensated modes of SLPH is used. In these modes, the gate driver current is increased by one step when the temperature warning threshold is reached. www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) Status OTPW 42 Description Range Overtemperature warning. This bit indicates 0 / 1 whether the warning threshold is reached. Software can react to this setting by reducing current. Overtemperature shutdown. This bit indicates 0 / 1 whether the shutdown threshold has been reached and the driver has been disabled. OT Comment 1: temperature prewarning level reached 1: driver shut down due to overtemperature 11.4 Undervoltage Detection The undervoltage detector monitors both the internal logic supply voltage and the supply voltage. It prevents operation of the chip when the MOSFETs cannot be guaranteed to operate properly because the gate drive voltage is too low. It also initializes the chip at power up. In undervoltage conditions, the logic control block becomes reset and the driver is disabled. All MOSFETs are switched off. All internal registers are reset to zero. Software also should monitor the supply voltage to detect an undervoltage condition. If software cannot measure the supply voltage, an undervoltage condition can be detected when the response to an SPI command returns only zero bits in the response and no bits are shifted through the internal shift register from SDI to SDO. After a reset due to undervoltage occurs, the CS parameter is cleared, which is reflected in an SE status of 0 in the read response. VVS VUV ca. 100µs ca. 100µs Time Device in reset: all registers cleared to 0 Reset Figure 11.2 Undervoltage reset timing Note: Be sure to operate the IC significantly above the undervoltage threshold to ensure reliable operation! Check for SE reading back as zero to detect an undervoltage event. www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 43 12 Power Supply Sequencing The TMC262 generates its own 5V supply for all internal operations. The internal reset of the chip is derived from the supply voltage regulator in order to ensure a clean start-up of the device after power up. During start up, the SPI unit is in reset and cannot be addressed. All registers become cleared. VCC_IO limits the voltage allowable on the inputs and outputs and is used for driving the outputs, but input levels thresholds are not depending on the actual level of VCC_IO. Therefore, the startup sequence of the VCC_IO power supply with respect to VS is not important. www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 44 13 System Clock The internal system clock frequency for all operations is nominally 15MHz. An external clock of 10MHz to 20MHz (16MHz recommended for optimum performance) can be supplied for more exact timing, especially when using coolStep and stallGuard2. Alternatively, the on-chip oscillator clock frequency can be determined by measuring the delay time between the last step and assertion of the STST status bit, which is 220 clocks. There is some delay in reading the STST bit through the SPI interface, but it is possible to measure the oscillator frequency within 1%. Chopper timing parameters can then be corrected using this measurement, because the oscillator is relatively stable over a wide range of environmental temperatures. An external clock frequency of up to 20MHz can be supplied. The external clock is enabled and the onchip oscillator is disabled with the first logic high driven on the CLK input. To use the on-chip oscillator, tie CLK to GND near the chip. If the external clock is suspended or disabled after the oscillator has been disabled, the chip will not operate. Be careful to switch off the power MOSFETs (by driving the ENN input high or setting the TOFF parameter to 0) before switching off the clock, because otherwise the chopper would stop and the motor current level could rise uncontrolled. If the short to GND detection is enabled, it stays active even without clock. 13.1 Frequency Selection A higher frequency allows faster step rates, faster SPI operation, and higher chopper frequencies. On the other hand, it may cause more electromagnetic emission and more power dissipation in the digital logic. Generally, a system clock frequency of 8MHz to 16MHz should be sufficient for most applications, unless the motor is to operate at the highest velocities. If the application can tolerate reduced motor velocity and increased chopper noise, a clock frequency of 4MHz to 8MHz should be considered. www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 45 14 MOSFET Examples There are a number of N- and P-channel paired MOSFETs available suitable for the TMC262, as well as single N- and P-devices. The important considerations are the electrical data (voltage, current, RDSon), package, and configuration (single vs. dual). The following table shows a few examples of SMD MOSFET pairs for different motor voltages and currents. These MOSFETs are recent types with a low total gate charge. For the actual application, you should calculate static and dynamic power dissipation for a given MOSFET pair. A gate charge below 20nC (at 5V) is best for reaching reasonable slopes. Transistor Type Unit SUD23N06 SUD19P06 SI7414 SI7415 SI7530 SI4559ADY IRF7343 FDD8647L FDD4243 FDD8424H SI4565DY SI4567DY SI3529DV FDS8960C BSZ050N03 BSZ180P03 FDS8958A TMC34NP SI4544DY SI4539ADY SI4532ADY IRF9952 Manufacturer Vishay Voltage VDS Max. RMS Current (*) V A 60 6 Package DPAK Vishay 60 3 PPAK1212 Vishay Vishay Vishay Fairchild 60 60 55 3 2.2 1.8 PPAK-SO8 SO8 SO8 40 6 Fairchild Vishay Vishay Vishay Fairchild 40 40 40 40 35 4.2 3 2.5 1.5 3.3 Infineon 30 8 Fairchild TRINAMIC Vishay Vishay Vishay Vishay 30 30 30 30 30 30 3.2 3 3 2.8 2.7 2 DPAK DPAK-4L SO8 SO8 TSOP-6 SO8 S3O8 SO8 PPAK1212 SO8 SO8 SO8 SO8 RDSon N (5V) RDSon P (8V) QG N QG P mΩ 35 mΩ nC 8 nC 50 28 70 55 55 13 25 35 60 110 20 7 25 35 40 45 50 80 22 9 60 55 110 125 40 45 45 80 190 45 18 45 50 40 50 70 220 6 7 13 12 9 9 6 2.5 6 13 6 5 9 6 4 4 12 22 12 22 18 14 13 10 4 9 15 9 11 15 12 8 5.5 * The maximum motor current applicable in a given design depends upon PCB size and layout, because all of these transistors are mainly cooled through the PCB. The data given implies adequate cooling measures in the design, especially for higher current designs. The maximum RMS current rating takes into account package power dissipation, on resistances, and gate charges. www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 46 15 External Power Stage The TMC262 uses a completely complementary driving scheme for the power MOSFETs. This allows using the low-side gate driver outputs to control external gate drivers for the power MOSFETs. In this case, the external gate driver must provide the break-before-make function. You can directly connect gate driver chips like the TMC603 as gate drivers for high-current NMOS transistor bridges. The TMC603 also supplies a gate-drive voltage regulator and allows 100% duty cycle. See the TMC603 datasheet for more information. The examples below show standard low-side and high-side drivers for boosting the TMC262. The higher gate-driving capability allows designs that exceed 20A and voltages above 60V. Two example schematics are shown for different gate-driver configurations. +V12 VHS 100n VCC_IO 5VOUT BHB 470nF D HA1 CLK HA2 D +V12 BMA1 step & dir (optional) STEP DIR D Provide sufficient filtering capacity near bridge transistors (electrolyt capacitors and ceramic capacitors) +VM up to 80V 10µF 10µF BHO AHO 2R2 2R2 VDD DIS D Full bridge gate driver IC AHI D N G N G S BHS BHI BMA2 D AHB HIP4082 (Intersil) 100µF 100n 8-20MHz Attention: High side capacitors would discharge at 100% duty cycle within a few seconds. Disable driver if open load occurs in stand still. +V12 VM TMC262 +VCC 3.3V or 5V 100n 16V 12V gate supply S AHS LA2 BLI ALO LA1 ALI BLO High current NMOS FET switches motor coil A D 2R2 D N G N G S S 2R2 TEST_SE ENABLE CSN SCK SPI SDI SDO DLY D VSS RSENSE SRA D 20mΩ for 14A peak (resp. 7A peak) 22R D RDLY 10k D SRB D D Second bridge identical LB1 stallGuard output SG_TST LB2 D +V12 BMB2 BMB1 HB2 HB1 DIE PAD GND TEST_ANA Figure 15.1 High-current, high-voltage power stage using external gate drivers (minimum part count) The short to GND protection of the TMC262 cannot be used in the configuration shown in Figure 15.1. The driver cannot be fully disabled, because the external gate driver just switches on either the highside MOSFET or the low-side MOSFET. In this configuration, the external driver adds break-before-make capability. A configuration that takes advantage of the TMC262 short to GND protection is shown in Figure 15.2. The control style shown in this example can also be applied to the gate driver shown in Figure 15.1. www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 47 +VM 100n 100n 16V VHS +VCC VCC_IO 3.3V or 5V TMC262 5VOUT +10V 470nF D 100n 8-20MHz 470pF CLK Attention: High side capacitors would discharge at 100% duty cycle within a few seconds. Disable driver if open load occurs in stand still. optional capacitor increases BBM time by roughly 70ns at min. SLPH setting VM +VM up to 60V 10V gate supply 1K 47µF D 2R2 HA1 D Provide sufficient filtering capacity near bridge transistors (electrolyt capacitors and ceramic capacitors) D N G N G S S High current NMOS FET switches 4.7µF BC856 HS-Driver step & dir (optional) STEP DIR TEST_SE ENABLE CSN SCK SPI SDI SDO stallGuard output SG_TST BMA1 D motor coil A 560R D LA1 D LSDriver 2R2 D N G N G S S ISL6700 or LM5107 or similar D RSENSE SRA D 20mW for 14A peak (resp. 7A peak) 22R D D D D Other half bridge(s) identical D DIE PAD GND TEST_ANA Figure 15.2 High-current power stage using external gate drivers with short to GND protection When using high-current gate drivers, pay special attention to manufacturers’ recommendations and application notes, especially concerning placement and layout of the circuit and additional parts not shown in the example figures, such as capacitors for supply voltage decoupling, protection diodes required in combination with some MOSFETs, etc. www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 48 16 Layout Considerations The PCB layout is critical to good performance, because the environment includes both highsensitivity analog signals and high-current motor drive signals. 16.1 Sense Resistors The sense resistors are susceptible to ground differences and ground ripple voltage, as the microstep current steps result in voltages down to 0.5mV. No current other than the sense resistor currents should flow through their connections to ground. Place the sense resistors close to the power MOSFETs with one or more vias to the ground plane for each sense resistor. The sense resistor layout is also sensitive to coupling between the axes. The two sense resistors should not share a common ground connection trace or vias, because PCB traces have some resistance. 16.2 Exposed Die Pad The exposed die pad and all GND pins must be connected to a solid ground plane spreading heat into the board and providing for a stable GND reference. All signals of the TMC262 are referenced to GND. Directly connect all GND pins to a common ground area. 16.3 Power Filtering The 470nF ceramic filtering capacitor on 5VOUT should be placed as close as possible to the 5VOUT pin, with its GND return going directly to the nearest GND pin. Use as short and as thick connections as possible. A 100nF filtering capacitor should be placed as close as possible from the VS pin to the ground plane. The motor supply pins, VSA and VSB, should be decoupled with an electrolytic (>47 μF is recommended) capacitor and a ceramic capacitor, placed close to the device. Take into account that the switching motor coil outputs have a high dV/dt, and thus capacitive stray into high resistive signals can occur, if the motor traces are near other traces over longer distances. www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 49 16.4 Layout Example top layer (assembly side) inner layer inner layer bottom layer (solder side) Figure 16.1 Layout example www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 50 17 Absolute Maximum Ratings The maximum ratings may not be exceeded under any circumstances. Operating the circuit at or near more than one maximum rating at a time for extended periods shall be avoided by application design. Parameter Supply voltage Supply and bridge voltage max. 20000s Logic supply voltage I/O supply voltage Logic input voltage Analog input voltage Voltages on low-side gate driver outputs (LSx) Voltages on high-side gate driver outputs (HSx) Voltages on BM pins (BMx) Relative high-side gate driver voltage (VVM – VHS) Maximum current to/from digital pins and analog low voltage I/Os Non-destructive short time peak current into input/output pins 5V regulator output current 5V regulator peak power dissipation (VVM-5V) * I5VOUT Junction temperature Storage temperature ESD-Protection (Human body model, HBM), in application ESD-Protection (Human body model, HBM), device handling www.trinamic.com Symbol VVS VVCC VVIO VI VIA VOLS VOHS VIBM VHSVM IIO IIO I5VOUT P5VOUT TJ TSTG VESDAP VESDDH Min Max Unit -0.5 60 V 65 V 6.0 6.0 VVIO+0.5 VCC+0.5 VCC+0.7 VVM+0.7 VVM+5 15 +/-10 V V V V V V V V mA 500 50 1 150 150 1 300 mA mA W °C °C kV V -0.5 -0.5 -0.5 -0.5 -0.7 VHS -0.7 -5 -0.5 -50 -55 TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 51 18 Electrical Characteristics 18.1 Operational Range Parameter Junction temperature Supply voltage TMC261 I/O supply voltage Symbol Min Max Unit TJ VVS VVIO -40 9 3.00 125 59 5.25 °C V V 18.2 DC and AC Specifications DC characteristics contain the spread of values guaranteed within the specified supply voltage range unless otherwise specified. Typical values represent the average value of all parts measured at +25°C. Temperature variation also causes some values to stray. A device with typical values will not leave Min/Max range within the full temperature range. Power Supply Current DC Characteristics VVS = 24.0V Parameter Symbol Conditions Supply current, operating IVS Supply current, MOSFETs off Supply current, MOSFETs off, dependency on CLK frequency IVS IVS Static supply current IVS0 Part of supply current NOT consumed from 5V supply IO supply current IVSHV IVIO Min fCLK=16MHz, 40kHz chopper, QG=10nC fCLK=16MHz fCLK variable additional to IVS0 fCLK=0Hz, digital inputs at +5V or GND MOSFETs off No load on outputs, inputs at VIO or GND DC Characteristics VLSX = 2.5V, slope setting controlled by SLPL Parameter Symbol Conditions Driver active output voltage www.trinamic.com Min Max Unit 12 mA 10 0.32 mA mA/ MHz mA 3.2 NMOS Low-Side Driver Gate drive current LSx low-side switch ON a) Gate drive current LSx low-side switch ON a) Gate drive current LSx low-side switch ON a) Gate drive current LSx low-side switch OFF a) Gate drive current LSx low-side switch OFF a) Gate drive current LSx low-side switch OFF a) Gate off detector threshold QGD protection resistance after detection of gate off Typ 4 1.2 mA 0.3 µA Typ Max Unit ILSON SLPL=%00/%01 12 mA ILSON SLPL=%10 21 mA ILSON SLPL=%11 ILSOFF SLPL=%00/%01 -13 mA ILSOFF SLPL=%10 -25 mA ILSOFF SLPL=%11 VGOD VLSX falling SLPL=%11 VLSX = 1V RLSOFFQGD VLSON 20 -25 31 -37 1 26 VVCC 50 -60 mA mA V 50 W V TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 52 Notes: a) Low-side drivers behave similar to a constant-current source between 0V and 2.5V (switching on) and between 2.5V and 5V (switching off), because switching MOSFETs go into saturation. At 2.5V, the output current is about 85% of peak value. This is the value specified. PMOS High-Side Driver DC Characteristics VVS = 24.0V, VVS - VHSX = 2.5V, slope setting controlled by SLPH Parameter Symbol Conditions Min Typ Max Unit Gate drive current HSx high-side switch ON b) IHSON SLPH=%00/%01 -15 mA Gate drive current HSx high-side switch ON b) Gate drive current HSx high-side switch ON b) Gate drive current HSx high-side switch OFF c) Gate drive current HSx high-side switch OFF c) Gate drive current HSx high-side switch OFF c) Gate off detector threshold QGD protection resistance after detection of gate off IHSON SLPH=%10 -29 mA IHSON SLPH=%11 IHSOFF SLPH=%00/%01 15 mA IHSOFF SLPH=%10 29 mA IHSOFF SLPH=%11 VGOD VHSX rising SLPH=%11 VHSX = VVS - 1V IOUT = 0mA Driver active output voltage RHSOFFQGD VHSON -25 28 VVHS+2.8 -42 43 -70 70 mA mA VVS-1 32 V 60 W VVHS+2.3 VVHS+1.8 V Notes: b) High-side switch on drivers behave similar to a constant-current source between VVS and VVS–2.5V. At VVS-2.5V, the output current is about 90% of peak value. This is the value specified. c) High-side switch off drivers behave similar to a constant current source between VVS-8V and VVS-2.5V. At VVS-2.5V, the output current is about 65% of peak value. This is the value specified. High-Side Voltage Regulator DC-Characteristics VVS = 24.0V Parameter Symbol Conditions Output voltage (VVM – VHS) VHSVM Output resistance Deviation of output voltage over the full temperature range DC Output current Current limit Series regulator transistor output resistance (determines voltage drop at low supply voltages) RVHS www.trinamic.com VVHS(DEV) IVHS IVHSMAX RVHSLV IOUT = 0mA TJ = 25°C Static load TJ = full range (from VM to VHS) (from VM to VHS) Min Typ Max Unit 9.3 10.0 10.8 V 200 W mV 50 60 15 400 4 mA mA 1000 W TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) Linear Regulator DC Characteristics Parameter Symbol Conditions Output voltage V5VOUT Output resistance Deviation of output voltage over the full temperature range Output current capability (attention, do not exceed maximum ratings with DC current) R5VOUT V5VOUT(DEV) I5VOUT Min Typ Max Unit I5VOUT = 10mA TJ = 25°C Static load I5VOUT = 10mA TJ = full range 4.75 5.0 5.25 V 60 W mV VVS = 12V 100 mA VVS = 8V 60 mA VVS = 6.5V 20 mA Clock Oscillator and CLK Input Timing Characteristics Parameter Symbol Conditions Clock oscillator frequency Clock oscillator frequency Clock oscillator frequency External clock frequency (operating) External clock high / low level time fCLKOSC fCLKOSC fCLKOSC fCLK tJ=-50°C tJ=50°C tJ=150°C tCLK Parameter Symbol Conditions Overtemperature warning Overtemperature shutdown VUV VBMS2G tOTPW tOT Min Typ 10.0 10.8 14.3 15.2 15.4 Max 20.0 20.3 20 12 DC Characteristics tS2G 3 30 4 Detector Levels VVS undervoltage threshold Short to GND detector threshold (VVS - VBMx) Short to GND detector delay (low-side gate off detected to short detection) 53 TS2G=00 Unit MHz MHz MHz MHz ns Min Typ Max Unit 6.5 1.0 8 1.5 8.5 2.3 V V 2.0 3.2 4.5 µs TS2G=10 TS2G=01 1.6 1.2 µs µs TS2G=11 0.8 µs Temperature rising 80 135 100 150 120 170 °C °C Min Typ Max Unit 290 310 330 mV 153 165 180 mV Sense Resistor Voltage Levels DC Characteristics Parameter Sense input peak threshold voltage (low sensitivity) Sense input peak threshold voltage (high sensitivity) www.trinamic.com Symbol Conditions VSRTRIPL VSRTRIPH VSENSE=0 Cx=248; Hyst.=0 VSENSE=1 Cx=248; Hyst.=0 TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) Digital Logic Levels 54 DC Characteristics Parameter Symbol Conditions d) Input voltage low level Input voltage high level d) Output voltage low level Output voltage high level Input leakage current VINLO VINHI VOUTLO VOUTHI IILEAK Min -0.3 2.4 IOUTLO = 1mA IOUTHI = -1mA 0.8VVIO -10 Typ Max 0.8 VVIO+0.3 0.4 10 Unit V V V V µA Notes: d) Digital inputs left within or near the transition region substantially increase power supply current by drawing power from the internal 5V regulator. Make sure that digital inputs become driven near to 0V and up to the VIO I/O voltage. There are no on-chip pull-up or pulldown resistors on inputs. www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 55 19 Package Mechanical Data 19.1 Dimensional Drawings Attention: Drawings not to scale. Figure 19.1 Dimensional drawings Parameter Total thickness Standoff Mold thickness Lead frame thickness Lead width Body size X Body size Y Lead pitch Exposed die pad size X Exposed die pad size Y Lead length Package edge tolerance Mold flatness Coplanarity Lead offset Exposed pad offset Ref A A1 A2 A3 b D E e J K L aaa bbb ccc ddd eee Min 0.80 0.00 0.2 3.2 3.2 0.35 Nom 0.85 0.035 0.65 0.203 0.25 5.0 5.0 0.5 3.3 3.3 0.4 Max 0.90 0.05 0.67 0.3 3.4 3.4 0.45 0.1 0.1 0.08 0.1 0.1 19.2 Package Code Device TMC262 www.trinamic.com Package QFN32 (RoHS) Temperature range -40° to +125°C Code/ Marking TMC262-LA TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 56 20 Disclaimer TRINAMIC Motion Control GmbH & Co. KG does not authorize or warrant any of its products for use in life support systems, without the specific written consent of TRINAMIC Motion Control GmbH & Co. KG. Life support systems are equipment intended to support or sustain life, and whose failure to perform, when properly used in accordance with instructions provided, can be reasonably expected to result in personal injury or death. Information given in this data sheet is believed to be accurate and reliable. However no responsibility is assumed for the consequences of its use nor for any infringement of patents or other rights of third parties which may result from its use. Specifications are subject to change without notice. All trademarks used are property of their respective owners. 21 ESD Sensitive Device The TMC262 is an ESD-sensitive CMOS device and sensitive to electrostatic discharge. Take special care to use adequate grounding of personnel and machines in manual handling. After soldering the devices to the board, ESD requirements are more relaxed. Failure to do so can result in defects or decreased reliability. Note: In a modern SMD manufacturing process, ESD voltages well below 100V are standard. A major source for ESD is hot-plugging the motor during operation. As the power MOSFETs are discrete devices, the device in fact is very rugged concerning any ESD event on the motor outputs. All other connections are typically protected due to external circuitry on the PCB. www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 57 22 Table of Figures Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure 1.1 Applications block diagrams ......................................................................................................................... 4 2.1 TMC262 pin assignments ................................................................................................................................ 6 3.1 TMC262 block diagram .................................................................................................................................... 8 4.1 stallGuard2 load measurement SG as a function of load .................................................................... 9 4.2 Linear interpolation for optimizing SGT with changes in velocity .................................................. 11 5.1 Energy efficiency example with coolStep ................................................................................................ 13 5.2 coolStep adapts motor current to the load ............................................................................................ 14 6.1 SPI Timing ........................................................................................................................................................ 16 6.2 Interfaces to a TMC429 motion controller chip and a TMC262 motor driver ............................... 17 7.1 STEP/DIR timing .............................................................................................................................................. 27 7.2 Internal microstep table showing the first quarter of the sine wave ........................................... 28 7.3 microPlyer microstep interpolation with rising STEP frequency ...................................................... 29 8.1 Sense resistor grounding and protection components ...................................................................... 32 9.1 Chopper phases .............................................................................................................................................. 33 9.2 spreadCycle chopper mode showing the coil current during a chopper cycle ........................... 35 9.3 Constant off-time chopper with offset showing the coil current during two cycles ................ 36 9.4 Zero crossing with correction using sine wave offset ........................................................................ 36 10.1 MOSFET gate charge vs. VDS for a typical MOSFET during a switching event ............................ 39 11.1 Short to GND detection timing ................................................................................................................ 40 11.2 Undervoltage reset timing ......................................................................................................................... 42 15.1 High-current, high-voltage power stage using external gate drivers (minimum part count) 46 15.2 High-current power stage using external gate drivers with short to GND protection............ 47 16.1 Layout example ............................................................................................................................................. 49 19.1 Dimensional drawings ................................................................................................................................ 55 www.trinamic.com TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14) 58 23 Revision History Version Date Author Description BD = Bernhard Dwersteg SD – Sonja Dwersteg 0.94 1.00 2010-APR-22 2010-AUG-09 BD BD 1.07 2010-NOV-22 BD 1.08 1.10 1.11 1.12 1.13 1.15 2.00 2010-DEC-01 2011-MAR-09 2011-APR-12 2011-JUL-26 2011-OKT-05 2011-DEC-14 2012-FEB-03 BD BD BD BD BD BD SD 2.01 2.02 2012-FEB-20 2012-MAR-29 SD SD 2.03 2012-JUN-07 SD 2.04 2012-AUG-01 SD 2.05 2.06 2012-AUG-13 2012-NOV-05 SD SD 2.07 2013-FEB-14 BD New headline, photo, details V2 silicon results, increased chopper thresholds (identical ratio of VCC power supply as in V1 and V1.2 silicon) VSENSE bit description corrected based on actual values Changed optimum SG value range to 0 to 400 at max. load, lower SGT limit for best results: -10, Chapter on stall detect. Added disclaimer, added SPI info Corrected undervoltage threshold, chopper thresholds Slightly modified LS driver characteristics Updated MOSFET list, typ. fCLKOSC is 15MHz (old: 13MHz) Corrected chopper illustration, new ext. driver application Minor corrections, added layout considerations - Amended datasheet version for TMC262 (design and wording). - Figure 5.1 new. - Application examples on second front page new. Microstep resolution corrected (6.5.2). - Description for CS parameter corrected (5) - New table design for signal descriptions (2.2) - Information about power supply sequencing added (12). - Chapter 6.4.2: table layout corrected. - Information about power supply sequencing updated. - Figure 11.2 (undervoltage reset timing) new Chapter 8 corrected: The low sensitivity (high sense resistor voltage, VSENSE=0) brings best and most robust current regulation, while high sensitivity (low sense resistor voltage; VSENSE=1) reduces power dissipation in the sense resistor. - Figure 15.2 (high current power stage) corrected - Corrected electrical specs of PMOS high side driver 24 References [TMC260] [TMC261] [TMC262-EVAL] [TMC32NP-PSO] [TMC34NP-PSO] TMC260/261 Datasheet TMC260/261 Datasheet TMC262-EVAL Manual TMC32NP-PSO MOSFET Datasheet TMC34NP-PSO MOSFET Datasheet Please refer to our web page http://www.trinamic.com. www.trinamic.com