I have burnt now a few LM1875 with single power supply using 55 Volts !
Chips are from AliEXpress.
Have others been as lucky as I.
LM1875 works with lower supply voltage, but using 55 Volts it burns immediatelly.
Data books say; max single power supply voltage is 60 Volts. True is that is not !
Me
Chips are from AliEXpress.
Have others been as lucky as I.
LM1875 works with lower supply voltage, but using 55 Volts it burns immediatelly.
Data books say; max single power supply voltage is 60 Volts. True is that is not !
Me
Uh, so grazy.
I go and try to locally (Finland) buy one more LM1875, if it is not China chip, and test if it's works like databooks say.
I let you know, what happens.
I go and try to locally (Finland) buy one more LM1875, if it is not China chip, and test if it's works like databooks say.
I let you know, what happens.
I try to put LM1875 instead
to philips MFB_ Speaker_22rh532 to drive middle and high speaker, systen works with single 60 volts.
That shows 57 volts rail voltage which I would suggest could be exceeded depending on mains voltage for example.
Its right on the limit of the absolute max rating. Why not use a bulb tester initially. Also Farnell have genuine chips.
Its right on the limit of the absolute max rating. Why not use a bulb tester initially. Also Farnell have genuine chips.
It has been said before I'll repeat the message 🙂 which is "Only ever buy semiconductors from authorised distributors".
Or do not use parts at max ratings.
Just like you do not drive your car in red all the time.
Just like you do not drive your car in red all the time.
Max volt - 3 volts should be area, which chip must accept without burning. Its 5% under max voltage value.
Stick to 80%, or about +/- 24 V for long life and stable performance on genuine 1875.
D2030 from China works nice on +/- 12V (19V rail to rail), it is their version of TDA series.
Triangle brand Chinese is marked D1875, I think, stay within +/- 15V.
Note that Chinese branded parts are more trustworthy than those with ST or TI markings.
And buy from a genuine source.
Otherwise try a huge heat sink, or a transistor based amp design, 1943 / 5200 pair is famous.
D2030 from China works nice on +/- 12V (19V rail to rail), it is their version of TDA series.
Triangle brand Chinese is marked D1875, I think, stay within +/- 15V.
Note that Chinese branded parts are more trustworthy than those with ST or TI markings.
And buy from a genuine source.
Otherwise try a huge heat sink, or a transistor based amp design, 1943 / 5200 pair is famous.
Look at the data sheet for safe voltage ratings, stay within typical rather than max. ratings...+/- 25V for 1875.
I would play safe and go about +/- 20V, that would still give a decent power output.
If you go higher, you will go near the danger zone, close to the limits of the device.
And way too loud for most users.
I would play safe and go about +/- 20V, that would still give a decent power output.
If you go higher, you will go near the danger zone, close to the limits of the device.
And way too loud for most users.
I have been burnt by 100 units of TDA2050
ST brand, bought from supposedly trusted importer, and yet ....
They "work" on +/-22V rails, within "official" ratings, but overheat, put out less than rated power and sound fuzzy, scope shows weird waveform limiting before reaching positive rail, all showing they are beyond safe voltage (for them).
Now they work perfectly, clean, as long as you want, no overheating, with +/-16, even +/-18V rails, strongly hinting they have a TDA2030 class chip inside.
There must be some Oriental factory churning them out by the Millions, no kidding, then finishers package them and silkscreen/burn whatever label they think will sell.
You got some of those.
As Naresh suggests, "downgrade" them to known TDA2030 specs and you will be fine.
Personally I needed a 25 W Guitar amp in my product line, not interested in 15W ones on which there is cutthroat competition, so to avoid wasting my purchase I had to design a 30 W bridged amp, the advantage is now I use them twice as fast 😄
You might do the same: use two generic/second source TDA2030 bridged, OR buy the real thing from the big serious distributors or straight from TI
Similar situation with LM3886: post COVID scarcity forced me to design a discrete substitute module, based on TIP122/127 Darlingtons.
Obsolete by now but still cheap and in ample supply.
"When Life gives you lemons .... you make lemonade" ... what else? ☹️
Using a chip amplifier, is possibility to get much better sound than with separate transistors, because in chip all are made to same base silicon. All transistors are like pairs together.
- Status
- Not open for further replies.