Hi All,
Are there any known good substitutes for U11 (LM6172IM) in older BD amps?
I realize that has to be a pretty fast Opamp, based on function.
Any experience with the HTCSemi HT6172ARZ? And yes I know Digi-Key has them in stock at $10 each.
Thanks in advance!
Are there any known good substitutes for U11 (LM6172IM) in older BD amps?
I realize that has to be a pretty fast Opamp, based on function.
Any experience with the HTCSemi HT6172ARZ? And yes I know Digi-Key has them in stock at $10 each.
Thanks in advance!
I couldn't find anything on the HTC IC.
The cost will be passed onto the owner. Even if you gave a quote that you cannot change, $10 should be insignificant in the overall cost of parts.
Are you 100% sure its defective?
The cost will be passed onto the owner. Even if you gave a quote that you cannot change, $10 should be insignificant in the overall cost of parts.
Are you 100% sure its defective?
Hi Perry,
Thanks and see attached. Yes, the cost will be passed on to the owner. I just thought I would ask to see if there are any known substitutes that may be easier to obtain. Also, with the chip shortages knowing good substitues always helps.
Unfortunately, it is defective. In circuit it only outpust ~9V. I did throw an TL072 into its place to make sure that would produce the square and triangle waves, but with it being so slow, the amp did not like that 🙂, obviously.
Thanks and see attached. Yes, the cost will be passed on to the owner. I just thought I would ask to see if there are any known substitutes that may be easier to obtain. Also, with the chip shortages knowing good substitues always helps.
Unfortunately, it is defective. In circuit it only outpust ~9V. I did throw an TL072 into its place to make sure that would produce the square and triangle waves, but with it being so slow, the amp did not like that 🙂, obviously.
I agree that a plan-B is good.
The following might work but it still expensive.
https://www.mouser.com/ProductDetail/Analog-Devices/LT1819IS8PBF?qs=ytflclh7QUU6kFewHghjiw==
You could even try an LM393 with a pull-up resistor between the output pins and the positive supply pins.
The following might work but it still expensive.
https://www.mouser.com/ProductDetail/Analog-Devices/LT1819IS8PBF?qs=ytflclh7QUU6kFewHghjiw==
You could even try an LM393 with a pull-up resistor between the output pins and the positive supply pins.
Thanks Perry,
I also considered the LT1819, but with the lower 12.6V Total Supply Voltage, I reconsidered. If I remember correctly there is about 20V in this application.
I did not know I could use a comparator as an integrator to generate the triangle wave. Never tried that before.
Thanks again! I may get the original and the HTC Semi and see if they both work.
I also considered the LT1819, but with the lower 12.6V Total Supply Voltage, I reconsidered. If I remember correctly there is about 20V in this application.
I did not know I could use a comparator as an integrator to generate the triangle wave. Never tried that before.
Thanks again! I may get the original and the HTC Semi and see if they both work.
LM7372MRX/NOPB could possibly also work, but again I will start with originals.
https://www.mouser.com/ProductDetail/Texas-Instruments/LM7372MRX-NOPB?qs=QbsRYf82W3HmWyNrmziXOg==
https://www.mouser.com/ProductDetail/Texas-Instruments/LM7372MRX-NOPB?qs=QbsRYf82W3HmWyNrmziXOg==
The HTC part is only 7.5v.
I'm not sure the 393 will work but many class D amps use comparators in the high-frequency circuits. The triangle waveform doesn't require blinding speed.
I'm not sure the 393 will work but many class D amps use comparators in the high-frequency circuits. The triangle waveform doesn't require blinding speed.
Closing this out for others.
I ended up using the original part for U11, which restored the triangle wave generation. No alternatives were tried, since the amp was still not functional at this point.
U17 was also defective, with pins 2 and 6 connected the output was +702mV. Replacing U17 restored operation. I did not go back to try alternatives for U11.
I ended up using the original part for U11, which restored the triangle wave generation. No alternatives were tried, since the amp was still not functional at this point.
U17 was also defective, with pins 2 and 6 connected the output was +702mV. Replacing U17 restored operation. I did not go back to try alternatives for U11.