[ Context: we're looking for a PMU for GTA04 and beyond. One possible choice is to use NXP's PCF50633 again. ]
Andy Green wrote: > NXP is "the devil we know", but there is no integral codec. In the past, we had lots of trouble with the NXP PMUs, since their default settings (such as which regulators are active in what state, and what voltage they default to) are mask-programmed in the chip, there is only a small number of chip variants (they can also make custom variants, but we don't have quite the numbers for that ;-), and they never quite do what we need. So we ended up shuffling things around endlessly, tried to figure out work-arounds for incorrect voltages, and are supplying chips with voltages outside the guaranteed specs. NXP understand that this is a problem and mentioned that they are considering to use some EEPROM or similar in future chips to allow customer-specific configurations. Of course, this doesn't help us with GTA04. However, since GTA04 will have an MPU, we're considerably better off there. What we still have to worry about is: - feeding the MPU (unfortunately, the upper end of the MSP430's voltage range is only 3.6V. Otherwise, we could just have connected it to Vsys.) - make sure no regulator defaults to "on" and a higher voltage than allowed on the respective rail - make sure nothing goes berserk if some power rails come up a bit later than the rest (but that's a general problem anyway) So making the PCF50633 fit wouldn't be quite the pain it was in GTA02. - Werner
