Power Measurement - Altera Cyclone III Reference Manual

Figure 2–18. Power Measurement Circuit
Altera Corporation
March 2008

Power Measurement

Eight power supply rails have on-board voltage and current sense
capabilities. These measurements are made using an 8-channel
differential A/D converter from Linear Technology, with a serial data bus
connected to the MAX II CPLD.
The MAX II CPLD contains a logic design that continually monitors the
power rails and displays the current in mV on the dedicated four-digit
7-segment display. Rotary switch SW4 is used to select the power rail
being displayed. The sense resistor is large enough that it can be easily
probed by a user to confirm the display results. The results are also
accessible from the FPGA through register access across the FSM bus.
Figure 2–18 illustrates the circuit.
Table 2–16 on page 2–25
Schematic Signal Name lists the power rail being measured, and the power
pins/devices attached to the power rail are listed in the Power Pin Name
and Description columns.
Reference Manual
lists the power measurement rails. The column
Cyclone III Development Board
Board Components
2–79