Sense Circuits - Renesas RAA306012 User Manual

RAA306012 RSSK User's Manual
4.3.2

Sense Circuits

4.3.2.1 Current Sense (Internal)
This Evaluation Board is also available to detect the U, V, and W phase currents by connecting the U, V, and
W phase shunt resistors to the RAA306012's built-in differential amplifiers. The differential amplifiers are
disabled in the sample program. When using the built-in differential amplifier for the motor current sense, refer
to Figure 4-7 to mount and remove 0[Ω] resistors, and change the smart gate driver register settings. The
relation between the phase current (Iin) flow to the shunt resistor (Rs) and the voltage input to the MCU (Vout)
is expressed by EQ 4-1. For details of the shunt resistors and differential amplifier gain, refer to 4.1.6 in the
"RAA306012 Application Notes: Hardware (R18AN0067EJ)".
Vout [ ���� ] = Iin [ ���� ] × Rs [ ���� ] × Gain [ ����/���� ] + �
EQ 4-1
R12UZ0128EJ0100 Rev.1.00
Nov 1, 2023
Iin Rs
Iin : Current flow to shunt resistor
Rs : Shunt resistor (0.05[Ω])
Gain: Differential amplifier gain
VDD : Smart Gate Driver VDD pin voltage
Vout : Voltage applied to A/D converter input port of the MCU
Figure 4-8 Current Sense Circuits (Internal)
VDD [ ���� ]
�
2
Smart
Gate
Driver
+
Diff.
Amp.
-
Vout
4. Peripheral Circuits
VDD
I
U
I
V
I
W
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