Mystery SMPS IC

Aug 04, 2013 14 Replies

Trying to source data (and possibly a part) for a switched mode psu control ic. Number is either BE737423 or 13E737423. This is on the main board of a small monochrome display monitor and seems to control the SMPS circuitry generating the internal power rails.



Anyone recognize it? Anyone have a data sheet? Anyone have one (!!) ?



Picture is worth a thousand words:



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AWEM



oops that didn't work try this:

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AWEM

Is there a recognisable makers logo on the chip?

Usually worth checking the actual capacitance and ESR of related capacitors. Some monitor designs weave the whole power supply into the line oscillator circuitry on the grounds of safety shutdown but making it a pig to diagnose. Sometimes forcing one of the low voltage rails up from a bench power supply can bring it back to life enabling diagnosis.

Good luck

Bob

Sadly no, Bob, no logos present.

AWEM

I have looked for 9-pin SIL packages on Google images. I didn't find anything exactly like yours. There were three kinds of IC:

  1. Vertical Deflection TDA3653B and AN5512
  2. Triple Video Output Amplifier TDA6108JF
  3. Adjustable Dual Tracking Voltage Regulator NE5554U I don't think a switched mode psu control IC would need a massive heatsink like on yours.

Hi Andrew,

I've seen you've posted the controller timing spec before

That's well within 'multisync' monitor frequencies - in the late

80s/early-mid 90s, if you bought a high-end monitor it could sync to a wide range of frequencies. Not just VGA/SVGA/XGA/etc.

Such monitors are now skip fodder, if you can find one. Otherwise there are probably LCDs with more liberal input acceptance than *GA out there.

Sadly I skipped my 17" CRT multisync the other week due to lack of takers, but it could sync 15-92KHz line rate.

Looks OK though it's a black box so, if it doesn't work, there's nothing to tweak. But it looks reasonably flexible. I'd be happier if I knew what chip it used.

Theo

Well spotted Adrian, but this is actually a different monitor - the previous one (which now works :) ) is on a Mitsubishi CNC controller, whereas this one is on a Heidenhain. - I expect they are both higher frequency than normal monitors.

AWEM

I found a test manual for a Heidenhain product on their website, showing waveforms for Horizontal and Vertical sync pulses for the display. They appeared to be standard TV 15KHz/50Hz. You might be able to find the appropriate waveforms for your CNC, whatever it is.

The monitor interface waveforms are illustrated in the lower half of this picture if you recognize the timing?

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AWEM

ST, Siemens or Infineon did produce a SMPS IC TDA4601 (google should find a datasheet) which matches the 9 pin SIL package of your chip. The initial 4604 identifier on your chip suggests it may be some sort of variant.

Graham

That looks like 32KHz/60Hz

i.e. the most common 640×480 standard VGA mode.

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For inspiration :)

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Picture is far too small and fuzzy to make out I'm afraid.

Thanks Adrian, interesting stuff you've been feeding me !

Andrew

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