Datasheet
TMC262 / TMC262C DATASHEET (Rev. 2.22 / 2019-FEB-22) 51
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16 Layout Considerations
The PCB layout is critical to good performance, because the environment includes both high-
sensitivity analog signals and high-current motor drive signals. A massive GND plane is required for
good results, both for heat conduction as well as electrical.
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. Each sense resistor should have an individual and
short connection to the GND plane. Place the sense resistors close to the power MOSFETs with one or
more vias to the ground plane for each sense resistor. This also helps to keep harmful parasitic
inductance small.
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 to 10µF (6.3V, min.) 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.