M63155FP Renesas Electronics Corporation., M63155FP Datasheet - Page 18

• Manufacturer Part Number: M63155FP
• Description: 3 Phase Brushless Motor Controller
• Manufacturer: Renesas Electronics Corporation.

M63155FP
8. Current Control (RSS, RSM, CTL, TCL)
Rev.1.0, Sep.16.2003, page 18 of 40
RSS is the sensing input of the motor current. A filter resistor(Rnf) should be connected between this terminal and
the RSM terminal. A sensing resistor(RS) should be connected between the RSM and motor ground. The current
control circuit compares the voltage of the sensing resistor(RS) with the CTL terminal input voltage.
When the motor current reaches the threshold voltage (the CTL terminal input voltage), the current control circuit
shuts down the motor current with turning off the external FETs during the constant period determined by the
external elements on the TCL terminal. This function acts independent of the PWM input signal.
If the motor current is controlled by the only PWM input signal, this current control circuit acts as a motor current
limit protection circuit. In this case, the motor current limit value could be determined by the CTL input voltage.
(1) Current control function
from MCU
(2) Current limit function
Motor Current
Vctl
Motor Current
Toff Constant
PWM Input
5V typ.
Rcin
5V typ.
Rcin
(Tcl)
- M63155FP -
VCC1
/VCC2
- M63155FP -
VCC1
/VCC2
CTL
TCL
CTL
TCL
RSM
RSM
RSS
RSS
VM
VM
Cnf
Cnf
12V typ.
12V typ.
Fig. 8 Motor Current Control Function
Rnf
Rnf
M
M
RS
RS
Vctl /Rs
zero
the motor current is shut down while the constant period.
The period of the motor shutting down is given by:
limit sensing low pass filter resistor(Rnf) to compensate
the input impedance of current comparator.
limit protection circuit. In this case, the motor current is
controlled by the PWM input duty.
the motor current is shut down while the constant period
like as above mentioned in “(1) Current control function”.
value to compensate the input impedance of current
comparator.
The motor current is controlled by the CTL input voltage.
When the motor current reaches the threshold voltage,
The motor control current value is given by:
The CTL input resistor(Rcin) sets the same value of the
The Current control circuit could be acted as the current
The value of the motor current limit is given by:
When the motor current reaches the limit current value,
The CTL input resistor(Rcin) sets the below equation
(Off
(Control
Rcl : Current control Off Time Resistance
Ccl : Current control Off Time Condenser
Vtcl : Current control Off Time Threshold Voltage
Vctl : CTL terminal input voltage (from MCU)
Rs : Motor current sensing resistor value
Vref : output voltage (ex.; VCC1=5V)
Rct1, Rct2 : VCC1 into CTL dividing resistor value
Rs : Motor current sensing resistor value
Rct1, Rct2 : VCC1 into CTL dividing resistor value
Rnf :
(Limit
Time)
Limit sensing low pass filter resistor
Current)
Current)
Rcin
R
cl
(Rct1//Rct
Vref
Ccl
Vctl
Rs
Rct
ln(
2)
Rct
1
VCC
Rnf
Rct
2
VCC
2
1
Rs
1
Vtcl
1
)
(typ; 2.5V)
value