In an embodiment, hardware implementing a transcendental or other non-linear function is based on a series expansion of the function. A document such as a driver’s license traverses a linear flowpath into and out of a housing having a darkened interior. When accessing a first portion of the first encrypted data stored in the external random access memory, a first algorithm is used to decrypt the first portion of the first encrypted data. The protection circuit is operative: to clamp the first signal to about the first voltage level when a third signal received at the signal pad exceeds the first voltage level by a first amount; and to generate the first signal being substantially equal to the third signal when the third signal is less than or substantially equal to the first voltage level. The motor is driven due to the electric power, and is operatively coupled to drive the compressor when the motor is energized. The conductive oxide film covers an end portion of the source wire that is exposed via a second hole in the passivation film.