Current Measurement

The SAMA5D2-ICP board embeds one PAC1934. The PAC1934 is a four-channel DC power/energy monitor with accumulator. A 16-bit ADC is used to measure voltages across a current sense resistor, connected by a differential multiplexer to (+) and (-) inputs for each channel.

Four current sense resistors (10 mΩ) are populated on-board for measuring voltage on power rails:

The PAC1934 communicates with the MPU via a TWI bus.

The figure below shows the current measurement.

Figure 1. PAC1934 Current Measurement
Table 1. PAC1934 Signal Descriptions
PIO Mnemonic Shared PIO Signal Description
PC28 PC28_PAC1934 POWER TWI TWI data
PC29 PC29_PAC1934 POWER TWI TWI clock
PB17 INT_PAC1934 Interrupt