Terminology

STPMS1

12/23

Doc ID 16524 Rev 2

6

Terminology

6.1

Conventions

The lowest analog and digital power supply voltage is named GND which represents the

system Ground. All voltage specifications for digital input/output pins are referred to GND.

Positive currents flow into a pin. Sinking current means that the current is flowing into the pin

and then it is positive. Sourcing current means that the current is flowing out of the pin and

then it is negative.

Timing specifications of a signal treated by a digital control part are relative to CLK. This

signal is provided from the STPMC1 calculator IC of 1.024 MHz or of 2.048 MHz nominal

frequency.

A positive logic convention is used in all equations.

6.2

Notation

Current and voltage signals are represented as u and i.