Datasheet

TMC2209 DATASHEET (Rev. 1.03 / 2019-JUN-26) 6
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In addition to these performance enhancements, TRINAMIC motor drivers offer safeguards to detect
and protect against shorted outputs, output open-circuit, overtemperature, and undervoltage
conditions for enhancing safety and recovery from equipment malfunctions.
1.2 Control Interfaces
The TMC2209 supports both, discrete control lines for basic mode selection and a UART based single
wire interface with CRC checking. The UART interface automatically becomes enabled when correct
UART data is sent. When using UART, the pin selection may be disabled by control bits.
1.2.1 UART Interface
The single wire interface allows unidirectional operation (for parameter setting only), or bi-directional
operation for full control and diagnostics. It can be driven by any standard microcontroller UART or
even by bit banging in software. Baud rates from 9600 Baud to 500k Baud or even higher (when
using an external clock) may be used. No baud rate configuration is required, as the TMC2209
automatically adapts to the masters’ baud rate. The frame format is identical to the intelligent
TRINAMIC controller & driver ICs TMC5130, TMC516x and TMC5072. A CRC checksum allows data
transmission over longer distance. For fixed initialization sequences, store the data including CRC into
the µC, thus consuming only a few 100 bytes of code for a full initialization. CRC may be ignored
during read access, if not desired. This makes CRC use an optional feature! The IC supports four
address settings to access up to four ICs on a single bus. Even more drivers can be programmed in
parallel by tying together all interface pins, in case no read access is required. An optional addressing
can be provided by analog multiplexers, like 74HC4066.
From a software point of view the TMC2209 is a peripheral with a number of control and status
registers. Most of them can either be written only or are read only. Some of the registers allow both,
read and write access. In case read-modify-write access is desired for a write only register, realize a
shadow register in master software.
1.3 Moving and Controlling the Motor
1.3.1 STEP/DIR Interface
The motor is controlled by a step and direction input. Active edges on the STEP input can be rising
edges or both rising and falling edges as controlled by a special 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. The state sampled from the DIR input upon an active STEP edge
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. A step impulse with 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.
1.3.2 Internal Step Pulse Generator
Some applications do not require a precisely co-ordinate motion – the motor just is required to move
for a certain time and at a certain velocity. The TMC2209 comes with an internal pulse generator for
these applications: Just provide the velocity via UART interface to move the motor. The velocity sign
automatically controls the direction of the motion. However, the pulse generator does not integrate a
ramping function. Motion at higher velocities will require ramping up and ramping down the velocity
value via software.
STEP/DIR mode and internal pulse generator mode can be mixed in an application!
1.4 StealthChop2 & SpreadCycle Driver
StealthChop is a voltage-chopper based principle. It especially guarantees that the motor is absolutely
quiet in standstill and in slow motion, except for noise generated by ball bearings. Unlike other
voltage mode choppers, StealthChop2 does not require any configuration. It automatically learns the
UART
UART