Mosfet; Shunt Resistor - Renesas RAJ306010 User Manual

RAJ306010 RSSK(RTK0EML2C0S01020BJ)
4.3.1.

MOSFET

This board has an internal MOSFET for evaluation. However, it is also possible to connect an external MOSFET
board prepared by the user. The MOSFET is selected by switching the implementation of the MOSFET
connection selection resistors (R107-R124).
By default, the 0Ω resistors are mounted on the right side of the MOSFET connection selection resistors (R107-
R124), and the MOSFET on this board is enabled. In this configuration, the connection of external MOSFETs to
CN_INV is prohibited.
When using external MOSFETs, remove the right-side resistors and mount it on the left side land. By mounting
on the left side, the gate and source of the mounted MOSFETs on this board are changed to MOS_GND level to
prevent through-hole breakdown due to voltage instability.
Note: Depending on the motor and control method, the power supply voltage may exceed the withstand voltage
of the MOSFET. In this case, depending on the specification of the motor, please replace the MOSFETs or
connect an external MOSFETs, or use an external MOSFETs.
4.3.2.

Shunt resistor

Using the shunt current sense amplifier built in the RAJ306010, the power supply current is detected, and
overcurrent protection is performed by measuring the voltage difference between the two ends of the shunt
resistor connected to the ISENP/ISENN pin. A shunt resistor (R65: 100mΩ) is mounted on this board between
the MOS_GND pin (J5) and the GND input pin (J6). By default, the left side is selected by the Shunt resistor
selection resistors (R102-R105), so the shunt resistor (R65) on the board is enabled.
The external shunt resistor can be used via the MOSFET connection connector (CN_INV) by changing to the
right side of the shunt resistor selector. However, external shunt resistors tend to be more susceptible to noise
and other effects, so using an on-board shunt resistor (R65) is recommended. When using an external shunt
resistor, please pay careful attention to the wiring path and length.
R18UZ0078EJ0100 Rev.1.0
Mar 24, 2021
4. Function
Page 21