Book Analog Interfacing to Embedded Microprocessors
This can be used
for current sensing.
174 Analog Interfacing to Embedded Microprocessors
Figure 7.14
H-bridge current sensing.
There are a number of ICs that can control and drive stepper motors. The
L6201 from SGS-Thompson is a typical part. The L6201 can drive motors up
to 5A with supply voltages up to 48v. The L6201 includes internal flyback pro-
tection diodes and includes a thermal shutdown that turns the motors off if
the part overheats. The L6201 is available in DIP, SMT, and multiwatt pack-
ages (Figure 7.15).
The LM18200 from National is another motor driver IC. This part includes
a pin that provides a thermal warning when the device is about to overheat.
Unlike the L6201, the LMD18200 does not require a sense resistor in the
ground connection of the driver transistors. Instead, the LMD18200 has a sep-
arate pin that mirrors the current in the H-bridge. This pin (CURRENT
SENSE OUTPUT in Figure 7
annaabi.ee 
