TMC5130A DATASHEET (Rev. 1.14 / 2017-MAY-15)
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3.7.3 Reduction of Resistive Losses by Adding Schottky Diodes
Schottky Diodes can be added to the circuit to reduce driver power dissipation when driving high
motor currents (see Figure 3.9). The Schottky diodes have a conduction voltage of about 0.5V and will
take over more than half of the motor current during the negative half wave of each output in slow
decay and fast decay phases, thus leading to a cooler motor driver. This effect starts from a few
percent at 1.2A and increases with higher motor current rating up to roughly 20%. As a 30V Schottky
diode has a lower forward voltage than a 50V or 60V diode, it makes sense to use a 30V diode when
the supply voltage is below 30V. The diodes will have less effect when working with stealthChop due
to lower times of diode conduction in the chopper cycle. At current levels below 1.2A coil current, the
effect of the diodes is negligible.
OA1
N
Full Bridge A
stepper
motor
OA2
S
RSA
BRA
Driver
OB1
OB2
Full Bridge B
1A Schottky Diodes like MSS1P6
or MSS1P3 (VM limited to 30V)
RSB
BRB
Figure 3.9 Schottky diodes reduce power dissipation at high peak currents up to 2A (2.5A)
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TRINAMIC [ TRINAMIC MOTION CONTROL GMBH & CO. KG. ]
