[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

IR - SSTC Half-Bridge Driver



Original poster: "David Sharpe by way of Terry Fritz <twftesla-at-qwest-dot-net>" <sccr4us-at-erols-dot-com>

All

While searching the outer reaches of the Internet "Empire"
for information on series resonant half-bridge converters for
possible service for SSTC, I think I found a hidden diamond
in the rock pile.  The driver control chip is an International
Rectifier IR2153D, and it is predominantly used for SS
flourescent lamp ballasts.  The advantages to the experimenter
are:
1.  Readily available at Digikey for less then $3.00 ea. (US)
2.  Is functionally a combination of a 555 oscillator + T flip-flop
      and high and low side half bridge HV FET driver (600V
      level shift no less)!!!   :^)  Useful frequency from 10's of kHz
      to ~300kHz (or more).
3.  Chip will operate from ~10V to 600V input (with proper
      Vcc 5mA current limiting resistor or 5mA constant current
      source)
4.  Integral soft start and shut down (external gating) by pulling
      Ct pin low.  This will facilitate modulation efforts or hard
      shutdown with an overcurrent or fault condition.  Also
      may facilitate a highly desirable VCO function with only
      a few additional passive components.
5.  Frequency adjustable by adjusting Rt value, in flourescent
      lamp reference below (see first reference application
      circuit).
6.  Minimal parts count to build a SSTC from 50W to 1kW or
      more.
7.  May have sufficient drive to operate IGBT's in ZVS/ZCS
      operation.

  Reference the following links:

http://www.epeec.ethz.ch/pdf/broeck_epe2001.pdf
This is a discussion showing pertinent use of IR2153 (pgs 7-9)
for a half-bridge series resonant converter.  Note the
waveforms of the converter sinusoidal current versus
square wave voltage input (yep, it is ZCS - zero current
switching).  This is the key that suggested the use of this
chip for SSTC applications.

  http://www.irf-dot-com/product-info/datasheets/data/ir2153.pdf
Chip datasheet from IR.

  http://www.irf-dot-com/technical-info/an998/an-998.htm
Describes using IR215x chips in ballast circuits, and using
external passive components create a VCO function based
on lamp current.  (Gee, if based on resonator base current --
a self tuning SSTC??   :^)   )  Also notice that if the primary
of the SSTC replaces the 1mH ballast inductor, the "guts"
of a SSTC are all there.

I'm buying some at work for another project and give it a
whirl...

Regards
Dave Sharpe, TCBOR
Chesterfield, VA. USA