What sort of current limiting, if any, is used on the internal 5.1-V reference regulator output (VREF) -- I assume this is an LDO -- is it using a brickwall or voltage foldback current limiting approach? The customer is concerned that permanent damage may occur during a short circuit condition on this pin as the datasheet specifies the Vref pin has an absolute max current of -30mA, but has a short circuit current of -45mA typical which exceeds that. Given the fact that this rail isn't used internally, would the device continuously operate during this condition or is there an internal thermal limit that would shut down the device?