TMC248-LA DATASHEET (Rev. 1.01 / 2013-MAR-26)
29
Notes:
(1) These P-channel transistors have a high drain to gate charge, which may introduce destructive
current impulses into the HA/HB outputs by forcing them above the power supply level, especially
when the miller capacitance (QGD) of the low side MOSFET is lower and thus it switches more
quickly. As a thumb rule, the criteria is QGDHS / QGSHS * QGDHS / QGDLS > 2 (assuming slopes >100ns).
To ensure reliability, connect a 500mA or 1A Schottky diode to both HA and HB outputs against
VS to protect them. Types like MSS1P3, ZHCS1000, SS14 or BAR43 can be used.
(2) These N-channel transistors have a high drain to gate charge, which may introduce destructive
current impulses into the LA/LB outputs by forcing them below the ground level, especially when
the miller capacitance (QGD) of the high side MOSFET is lower and thus it switches more quickly.
As a thumb rule, the criteria is QGDLS / QGSLS * QGDLS / QGDHS > 2 (assuming slopes >100ns).
To ensure reliability, connect a 500mA or 1A Schottky diode to both LA and LB outputs against
GND to protect them against negative spikes. Types like MSS1P3, ZHCS1000, SS14 or BAR43 can be
used.
www.trinamic.com
TRINAMIC [ TRINAMIC MOTION CONTROL GMBH & CO. KG. ]
