In a message dated 8/19/98 9:25:44 AM Pacific Daylight Time,
martin@DC.CIS.OKSTATE.EDU writes:

<<
         Are there power H bridges that come in a package of some kind?
 If so, what external connections are there?  I imagine this as the
 solid-state version of a DPDT switch.  My question basically is what
 do these things look like?  If somebody has gone to the trouble of
 matching four FET's (probably 2 N channel and 2 P channel) in a can,
 this should simplify building any circuit that needs something like
 this.  I am thinking of stepper motor controllers as well as the DC
 motors described in earlier messages.  One might even be able to build
 inverters or synchronous rectifiers using them as long as the load's
 ground path doesn't connect the input and output of the bridges.

 Martin McCormick
  >>
Hello Martin,
SGS Thompson has done just that.  We use the LMD18200.  It will handel up to 6
amps at 40 volts.  It comes in a TO220-11 package.
We use them on our machine to control a steering device for mylar film.
They have a PWM input that is used to turn on the motor and control its speed,
a direction input, and a brake input to stop the motor.
For steppers you need two of them.

Dave Duley
dduley@dreitek.com
www.dreitek.com