Renesas RL78/G1F, User Manual

Page: 13 / 35

RL78/G1F Motor Driver Board GB01 User's Manual
R12UT0012EJ0100 Rev.1.00 Page 13 of 32
20.10.2020
8. Circuit Function
8.1 Inverter Control Circuit
The inverter control circuit control the motor using six Power MOS-FETs. The Power MOS-FETs use the 6-
phase timer outputs from the microcontroller via the predriver IC.
The inverter control circuit inputs the DC line voltage, U-phase voltage, V-phase voltage, W-phase voltage,
and shunt current to the A/D pins of the microcontroller. The analog values of each voltage and shunt current
can thus be measured. See sections
8.2
and
8.3
for details about how to detect the current and voltage,
respectively. The inverter control circuit also has a function to detect the overcurrent from the U-phase, V-
phase, and W-phase shunt current.
Figure 8-1 shows a schematic diagram of the inverter control circuit. Note that the inputs to the A/D pins
may actually pass through a voltage diver or an offset device. See the circuit diagram for details.
Motor
UP
UN
VP
VN
WP
WN
V
BUS
I
U
_OPA
I
V
_OPA
I
W
_OPA
V
U
V
V
V
W
OP-Amp
OP-Amp
OP-Amp
PGAG PGAI
V
N
PWM input
DC Bus voltage
Phase
voltage
Shunt current
(Via amplifier)
POWER
MOS- FET
Shunt current
(MCU built-in amplifier connection)
Midpoint
voltage
Figure 8-1 Schematic Diagram of Inverter Control Circuit