TMC262 DATASHEET

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 (V2.11 / 2014-MAY-12)
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 (V2.11 / 2014-MAY-12)
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. 2.12 / 2015-JAN-13)
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. 2.12 / 2015-JAN-13)
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. 2.12 / 2015-JAN-13)
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
SDO
10
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.
DO VIO
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.
Data output of SPI interface (Tristate)
TMC262 DATASHEET (Rev. 2.12 / 2015-JAN-13)
Pin
SDI
Number
11
Type
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 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 using a short wire to GND plane.
7
TMC262 DATASHEET (Rev. 2.12 / 2015-JAN-13)
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
VS-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
D
N
G
LA1
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
N-Gate
drivers
stallGuard 2
BACK
EMF
Protection &
Diagnostics
SHORT
TO GND
Phase polarity
Chopper
logic
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. 2.12 / 2015-JAN-13)
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. 2.12 / 2015-JAN-13)
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. 2.12 / 2015-JAN-13)
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
lower limit for stall
detection 4 RPM
100
150
11
200
250
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:
𝑠𝑡𝑎𝑙𝑙𝐺𝑢𝑎𝑟𝑑 𝑚𝑒𝑎𝑠𝑢𝑟𝑒𝑚𝑒𝑛𝑡 𝑒𝑟𝑟𝑜𝑟 = ±𝑚𝑎𝑥(1, |𝑆𝐺𝑇|)
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.
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TMC262 DATASHEET (Rev. 2.12 / 2015-JAN-13)
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.
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TMC262 DATASHEET (Rev. 2.12 / 2015-JAN-13)
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
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TMC262 DATASHEET (Rev. 2.12 / 2015-JAN-13)
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.
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TMC262 DATASHEET (Rev. 2.12 / 2015-JAN-13)
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.
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TMC262 DATASHEET (Rev. 2.12 / 2015-JAN-13)
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
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tZC
bit19
bit18
bit0
TMC262 DATASHEET (Rev. 2.12 / 2015-JAN-13)
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
n
Motio
3x linear RAMP
generator
ro
cont
Step &
Direction
pulse
generation
Position
comparator
Microstep
table
CLK
Realtime event trigger
l
VCC_IO
S1 (SDO_S)
STEP
D1 (SCK_S)
Output select
SPI or
Step & Dir
er
r Driv
M o to
TMC262
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
SPI control,
Config & Diags
Protection
& Diagnostics
POSCOMP
x
Sine Table
4*256 entry
Gate driver
Gate Driver
S
Gate driver
Gate Driver
System interfacing
RS
stallGuard2™
2 x Current
Comparator
2 x DAC
SG_TST
Third driver and motor
rol
cont
User CPU
m
Syste
Figure 6.2 Interfaces to a TMC429 motion controller chip and a TMC262 motor driver
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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. 2.12 / 2015-JAN-13)
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
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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. 2.12 / 2015-JAN-13)
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. 2.12 / 2015-JAN-13)
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
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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. 2.12 / 2015-JAN-13)
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
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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. 2.12 / 2015-JAN-13)
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. 2.12 / 2015-JAN-13)
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. 2.12 / 2015-JAN-13)
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. 2.12 / 2015-JAN-13)
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. 2.12 / 2015-JAN-13)
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. 2.12 / 2015-JAN-13)
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. 2.12 / 2015-JAN-13)
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. 2.12 / 2015-JAN-13)
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
𝑠𝑦𝑠𝑡𝑒𝑚 𝑐𝑙𝑜𝑐𝑘 𝑓𝑟𝑒𝑞𝑢𝑒𝑛𝑐𝑦
event. At that frequency, microsteps occur at a rate of
= 244𝐻𝑧.
16
2
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. 2.12 / 2015-JAN-13)
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. 2.12 / 2015-JAN-13)
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:
𝐼𝑅𝑀𝑆 =
𝐶𝑆 + 1
𝑉𝐹𝑆
1
∗
∗
32
𝑅𝑆𝐸𝑁𝑆𝐸 √2
The momentary motor current is calculated as:
𝐼𝑀𝑂𝑇 =
𝐶𝑈𝑅𝑅𝐸𝑁𝑇𝐴/𝐵 𝐶𝑆 + 1
𝑉𝐹𝑆
∗
∗
248
32
𝑅𝑆𝐸𝑁𝑆𝐸
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. 2.12 / 2015-JAN-13)
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
capacitors
SRB
no common GND path
not visible to TMC262
470nF
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:
𝑃𝑅𝑆𝑀𝐴𝑋 =
(𝑉𝑆𝐸𝑁𝑆𝐸 ∗
𝐶𝑆 + 1 2
)
32
𝑅𝑆𝐸𝑁𝑆𝐸
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. 2.12 / 2015-JAN-13)
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:
𝑁𝐶𝐿𝐾 = (𝑇𝑂𝐹𝐹 ∙ 32) + 12
The SD-Time is
1
𝑡 =
∙ 𝑁𝐶𝐿𝐾
𝑓𝐶𝐿𝐾
www.trinamic.com
Comment
Chopper off.
Off time setting.
(1 will work with
minimum blank time
of 24 clocks.)
TMC262 DATASHEET (Rev. 2.12 / 2015-JAN-13)
Parameter
TBL
CHM
34
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
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:
𝑡𝐵𝐿𝐴𝑁𝐾
𝑑𝐼𝐶𝑂𝐼𝐿𝐵𝐿𝐴𝑁𝐾 = 𝑉𝑀 ∗
𝐿𝐶𝑂𝐼𝐿
𝑑𝐼𝐶𝑂𝐼𝐿𝑆𝐷 = 𝑅𝐶𝑂𝐼𝐿 ∗ 𝐼𝐶𝑂𝐼𝐿 ∗
2 ∗ 𝑡𝑆𝐷
𝐿𝐶𝑂𝐼𝐿
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:
𝐻𝑦𝑠𝑡𝑒𝑟𝑒𝑠𝑖𝑠 𝑆𝑡𝑎𝑟𝑡 ≥ (𝑑𝐼𝐶𝑂𝐼𝐿𝐵𝐿𝐴𝑁𝐾 + 𝑑𝐼𝐶𝑂𝐼𝐿𝑆𝐷 ) ∗
2 ∗ 248 𝐶𝑆 + 1
∗
𝐼𝐶𝑂𝐼𝐿
32
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:
2µ𝑠
𝑑𝐼𝐶𝑂𝐼𝐿𝐵𝐿𝐴𝑁𝐾 = 24𝑉 ∗
= 6.4𝑚𝐴
7.5𝑚𝐻
𝑑𝐼𝐶𝑂𝐼𝐿𝑆𝐷 = 4.5Ω ∗ 1.41𝐴 ∗
2 ∗ 5µ𝑠
= 8.5𝑚𝐴
7.5𝑚𝐻
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. 2.12 / 2015-JAN-13)
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. 2.12 / 2015-JAN-13)
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. 2.12 / 2015-JAN-13)
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. 2.12 / 2015-JAN-13)
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. 2.12 / 2015-JAN-13)
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:
𝑡𝑆𝐿𝑂𝑃𝐸 =
𝑄𝑀𝐼𝐿𝐿𝐸𝑅
𝐼𝐺𝐴𝑇𝐸
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.
𝑡𝑆𝐿𝑂𝑃𝐸 =
www.trinamic.com
2.5𝑛𝐶
= 166𝑛𝑠
15𝑚𝐴
TMC262 DATASHEET (Rev. 2.12 / 2015-JAN-13)
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. 2.12 / 2015-JAN-13)
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. 2.12 / 2015-JAN-13)
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. 2.12 / 2015-JAN-13)
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. 2.12 / 2015-JAN-13)
44
13 System Clock
The clock is the timing reference for all functions. The internal system clock frequency for all
operations is nominally 15MHz. An external clock of 10MHz to 20MHz can be supplied for more exact
timing, especially when using coolStep and stallGuard2.
USING THE INTERNAL CLOCK FREQUENCY
To use the on-chip oscillator of the TMC262, tie CLK to GND near the chip. The actual on-chip oscillator
clock frequency can be determined by measuring the delay time between the last step and assertion
of the STST (standstill) status bit, which is 220 clocks. There is some delay in reading the STST bit
through the SPI interface, but it is easily 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.
In case well defined precise motor chopper operation are desired, it is supposed to work with an
external clock source.
USING THE EXTERNAL CLOCK FREQUENCY
An external clock frequency of up to 20MHz can be supplied. It is recommended to use an external
clock frequency between 10MHz and 16MHz for best performance. The external clock is enabled and
the on-chip oscillator is disabled with the first logic high driven on the CLK input.
Attention:
Never leave the external clock input floating. It is not allowed to remain within the transition region
(between valid low and high levels) for extended times, as spurious clock signals might corrupt
internal logic state. Provide an external pull down resistor, in case the driver pin (i.e. microcontroller
output) does not provide a safe level directly after power up. Therefore, also a clean clock switch over
is important to avoid any clock period shorter than the minimum clock time.
If the external clock is suspended or disabled after the internal 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 10MHz 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 10MHz should be
considered.
www.trinamic.com
TMC262 DATASHEET (Rev. 2.12 / 2015-JAN-13)
45
14 MOSFET Examples
There are a many 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
Manufacturer
Unit
QM6006D
QM6015D
AOD4130
AOD409
SUD23N06
SUD19P06
TMC1620-TO
AOD603A
SI7414
SI7415
QM6301S
AO4612
SI4559ADY
AOD4186
AOD4185
FDD8647L
FDD4243
QM4302D
QM4803D
FDD8424H
AOD609
TMC1420
AP4543GEH
AO4618
SI4599DY
AP4543GEM
FDS8960C
AP9934AGM
BSZ050N03
BSZ180P03
AP4509AGH
AO4616
FDS8958A
TMC1320-LA
AON7611
AP4503BGM
SI4532CDY
TMC1340-SO
AP2852GO
AP2451GY
UBIQ
Voltage
VDS
Max. RMS
Current (*)
V
A
60
8
Package
DPAK
A&O
60
7
DPAK
Vishay
60
6
DPAK
TRINAMIC
A&O
60
60
4
3
TO252-4L
TO252-4L
Vishay
60
3
PPAK1212
UBIQ
A&O
Vishay
60
60
60
3
2.5
2.5
A&O
40
8
Fairchild
SO8
SO8
SO8
DPAK
40
7
DPAK
UBIQ
UBIQ
Fairchild
A&O
TRINAMIC
APEC
A&O
Vishay
APEC
Fairchild
APEC
40
40
40
40
40
40
40
40
40
35
35
5.5
4
4
4
4
3.5
3.5
3
3
3.5
3
TO252-4L
TO252-4L
DPAK-4L
TO252-4L
PMPAK5x6
TO252-4L
SO8
SO8
SO8
SO8
SO8 (Fullbridge)
Infineon
30
11
S3O8
APEC
A&O
Fairchild
TRINAMIC
A&O
APEC
Vishay
TRINAMIC
APEC
APEC
30
30
30
30
30
30
30
30
30
20
4
3.5
3.5
3.5
3
3
3
3
2.5
2.5
TO252-4L
SO8
SO8
DFN3x3EP
DFN3x3EP
SO8
SO8
SO8 (Fullbridge)
TSSOP-8
2928-8
RDSon
N (5V)
RDSon
P (8V)
QG
N
QG
P
mΩ
mΩ
nC
nC
16
19
22
30
25
35
31
67
28
30
64
55
15
60
65
90
110
13
4
9
13
5
7
9
14
13
15
28
23
31
30
36
21
36
38
20
70
7
16
24
25
30
53
35
50
35
48
37
e160
22
8
50
64
95
e160
22
14
16
12
10
8
12
18
28
24
45
52
35
35
80
55
60
60
64
e70
35
27
e27
e27
70
19
12
40
30
35
45
40
37
45
22
45
50
45
75
cm²
e160
13
35
Test
board
size
11
6
9
5
7
8
3
5
8
6
6
13
15
9
6
5
2
6
3
7
8
9
e100
18
12
9
14
9
12
13
8
12
13
9
6
15
17
16
9
7
5
12
4
8
9
11
e40
e40
40
e40
41
40
e27
e27
e27
e27
e27
70
40
e27
e27
41
15
e27
e27
41
e27
e27
* For duty cycle limited operation, 1.5 times or more current is possible. The maximum motor current applicable
in a design depends upon PCB size and layout, because all of these transistors are mainly cooled through the
PCB. The data given implies a certain board size and layout, especially for higher current designs. The maximum
RMS current rating is a hint and is based on measurements on test boards with given size at reasonable heat
up. Estimations for not tested types are based on a comparable type (estimated board sizes marked e).
www.trinamic.com
TMC262 DATASHEET (Rev. 2.12 / 2015-JAN-13)
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
VS
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. 2.12 / 2015-JAN-13)
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
VS
+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. 2.12 / 2015-JAN-13)
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. A symmetrical layout for both fullbridges on both sides of the TMC262 makes it easiest to
ensure symmetry as well as minimum coupling and disturbance between both coil current regulators.
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 MOSFET bridge supply pins 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. 2.12 / 2015-JAN-13)
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. 2.12 / 2015-JAN-13)
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 (VVS – 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
VHSVS
IIO
IIO
I5VOUT
P5VOUT
TJ
TSTG
VESDAP
VESDDH
Min
Max
Unit
-0.5
60
V
-0.5
-0.5
-0.5
-0.5
-0.7
VHS -0.7
-5
-0.5
65
6.0
6.0
VVIO+0.5
VCC+0.5
VCC+0.7
VVS+0.7
VVS+5
15
+/-10
V
V
V
V
V
V
V
V
V
mA
500
50
1
150
150
1
300
mA
mA
W
°C
°C
kV
V
-50
-55
TMC262 DATASHEET (Rev. 2.12 / 2015-JAN-13)
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. 2.12 / 2015-JAN-13)
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 (VVS – VHS)
VHSVS
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 VS to VHS)
(from VS 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. 2.12 / 2015-JAN-13)
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
External clock transition time
fCLKOSC
fCLKOSC
fCLKOSC
fCLK
tJ=-50°C
tJ=50°C
tJ=150°C
Parameter
Symbol Conditions
Overtemperature warning
Overtemperature shutdown
VUV
VBMS2G
tOTPW
tOT
Typ
10.0
10.8
14.3
15.2
15.4
Max
20.0
20.3
20
TS2G=00
Unit
MHz
MHz
MHz
MHz
ns
VINLO to VINHI or back
DC Characteristics
tS2G
Min
12
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)
3
30
4
tCLK
tTRCLK
53
20
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. 2.12 / 2015-JAN-13)
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. 2.12 / 2015-JAN-13)
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. 2.12 / 2015-JAN-13)
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.
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TMC262 DATASHEET (Rev. 2.12 / 2015-JAN-13)
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. 2.12 / 2015-JAN-13)
58
23 Revision History
Version
Date
Author
Description
BD = Bernhard Dwersteg
SD – Sonja Dwersteg
1.00
2010-AUG-09
BD
2.00
2012-FEB-03
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
2.08
2013-MAY-14
BD
2.09
2.09a
2013-JUL-30
2013-OKT-31
SD
BD
2.10
2013-NOV-29
BD
2.11
2.12
2014-MAY-12
2015-JAN-13
SD
BD
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
- 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
Updated MOSFET reference list
Updated current ratings after tests / more coarse rating
System clock information updated.
Updated MOSFET list and blue box, corrected table width
for chapter 6.6
Added hint not to leave CLK input floating (blue box),
added external clock transition time parameter.
Updated MOSFET list.
Update to MOSFET list, rename some VM to VS, update
chapter 16.3 and 16.1.
24 References
[TMC260]
[TMC261]
[TMC2660]
[TMC262-EVAL]
[TMC1620-TO]
[TMC1420]
[TMC1320-LA]
TMC260/261 Datasheet
TMC260/261 Datasheet
TMC2660 Datasheet
TMC262-EVAL Manual
TMC1620 60V N&P MOSFET Datasheet
TMC1420 40V N&P MOSFET Datasheet
TMC1320 30V N&P full bridge MOSFET Datasheet
Please refer to our web page http://www.trinamic.com.
www.trinamic.com