Timeline for Consistent failure of THAT 1646 line driver IC. What could be the cause?
Current License: CC BY-SA 3.0
11 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jan 23, 2016 at 22:26 | answer | added | Spehro 'speff' Pefhany | timeline score: 1 | |
| Jan 9, 2016 at 10:32 | history | tweeted | twitter.com/StackElectronix/status/685770997140729856 | ||
| Jan 8, 2016 at 23:12 | comment | added | ThreePhaseEel | ...are the suppression diodes from the outputs to ground, or from the outputs to the rails? | |
| Jan 8, 2016 at 21:17 | comment | added | disorder | @ThreePhaseEel Can't post schematic right now but it involves filtering and protection. The diodes it uses are part of a TVS array package (SMDB12C). Most of the failures we have had in the past the line driver equiped unit was being plugged into a powered speaker or a line-level signal analyzer... never plugged into mic-in never coming close to seeing phantom). | |
| Jan 8, 2016 at 1:27 | comment | added | ThreePhaseEel | Can you post the schematic of an exemplar output stage, or are they using the Figure 8 reference circuit? Are the diodes blowing in a vain attempt to protect the line driver IC? Finally, what is the output plugged into when it fails? (XLR makes me think they're plugging a line-out into a mic-in, which works fine, until you do it with the phantom power turned on...) | |
| Jan 7, 2016 at 20:50 | history | edited | disorder | CC BY-SA 3.0 |
deleted 73 characters in body
|
| Jan 7, 2016 at 20:49 | comment | added | disorder | @ACD this gear actually does just that. That's what I meant by "suppression diode" | |
| Jan 7, 2016 at 19:47 | history | edited | disorder | CC BY-SA 3.0 |
added 79 characters in body
|
| Jan 7, 2016 at 19:47 | comment | added | ACD | Without seeing the circuit, I would guess what is happening is surges cause the output stage to blow up as described on page 9 of the datasheet. It recommends clamping each output to the respective supply rail. | |
| Jan 7, 2016 at 19:45 | comment | added | jippie | thatcorp.com/datashts/THAT_1606-1646_Datasheet.pdf Check the paragraph around fig. 8. | |
| Jan 7, 2016 at 19:41 | history | asked | disorder | CC BY-SA 3.0 |