Does anyone know of noise measurements done on typical current-source LED driver chips? Noise is not specified in their datasheets as its not typically germane to the application of driving LED strings.
Such chips are often simple 2-trerminal devices, which makes them seem like ideal local shunt-regulator floating active current sources if their noise is reasonably low. I suspect that it is, since noise is largely a semiconductor process issue, but I haven't seen that verfied anywhere.
Such chips are often simple 2-trerminal devices, which makes them seem like ideal local shunt-regulator floating active current sources if their noise is reasonably low. I suspect that it is, since noise is largely a semiconductor process issue, but I haven't seen that verfied anywhere.
Look for Walt Jung's 3-part article from 1990 on current sources - Sources 101_p1, _p2,
and Revisited.
Also, search here for - GLED431 - An Ultra Low noise LED Reference cell.
and Revisited.
Also, search here for - GLED431 - An Ultra Low noise LED Reference cell.
This one should have far less noise than the LEDs shot noise:
https://assets.nexperia.com/documents/data-sheet/NCR402T.pdf
but anything bandgap-based can well have more noise than the LED.
https://assets.nexperia.com/documents/data-sheet/NCR402T.pdf
but anything bandgap-based can well have more noise than the LED.