TMC262 DATASHEET (Rev. 2.07 / 2013-FEB-14)
48
16 Layout Considerations
The PCB layout is critical to good performance, because the environment includes both high-
sensitivity analog signals and high-current motor drive signals.
16.1 Sense Resistors
The sense resistors are susceptible to ground differences and ground ripple voltage, as the microstep
current steps result in voltages down to 0.5mV. No current other than the sense resistor currents
should flow through their connections to ground. Place the sense resistors close to the power
MOSFETs with one or more vias to the ground plane for each sense resistor.
The sense resistor layout is also sensitive to coupling between the axes. The two sense resistors
should not share a common ground connection trace or vias, because PCB traces have some
resistance.
16.2 Exposed Die Pad
The exposed die pad and all GND pins must be connected to a solid ground plane spreading heat into
the board and providing for a stable GND reference. All signals of the TMC262 are referenced to GND.
Directly connect all GND pins to a common ground area.
16.3 Power Filtering
The 470nF ceramic filtering capacitor on 5VOUT should be placed as close as possible to the 5VOUT
pin, with its GND return going directly to the nearest GND pin. Use as short and as thick connections
as possible. A 100nF filtering capacitor should be placed as close as possible from the VS pin to the
ground plane. The motor supply pins, VSA and VSB, should be decoupled with an electrolytic (>47 μF
is recommended) capacitor and a ceramic capacitor, placed close to the device.
Take into account that the switching motor coil outputs have a high dV/dt, and thus capacitive stray
into high resistive signals can occur, if the motor traces are near other traces over longer distances.
www.trinamic.com
TRINAMIC [ TRINAMIC MOTION CONTROL GMBH & CO. KG. ]
