Click image to enlarge
The L6203 is a DMOS full bridge driver, which can handle the high peak
current up to 5A and supply voltage up to 48V with RDS
(ON) of just 0.3 ohm. The chip can run the DC motor at 4A continuous with
proper heat sinking.
The above DC motor driver circuit is implemented with
L6203 chip
accompanied by a L6205 current controller. The current controller is used in
this circuit as a pair of latching comparators. When the current through the
motor reaches a level of approximately 1.57A (set by R7 and R8), the IC U1
(L6506) starts turning off and on the U2 (L6203) at 20KHZ to keep the
current below 1.57A. This is similar to fixed off time PWM drive. If the
motor stall, the current goes above the 2.0A (set by R9 and R10) then the
second comparator channel will toggle the enable line of U2 to actually
disable the driver, this limiter will also turn on and off at a frequency of
20KHZ. In case the motor is continuously stalled then when the F1 PTC
reset-able fuse reaches it cutoff temperature, it will then turn off the
current to the motor to protect the chip from blowing out. With a 20KHZ
chopping rate the maximum average running current is very close to 1.5A. It
is suitable to most robotic or other applications using the medium size
DC motor.
For additional
information and resources on stepper motor drivers see the
![[Under Construction]](images/undercon.gif)
