To measure the current draw of the MSPM0G3519 MCU using a multimeter, use the 3V3 jumper on the J101 jumper isolation block. The current measured includes the target device, LaunchPad circuits, and any current drawn through the BoosterPack plug-in module headers. To measure ultra-low power, follow these steps:
- Remove the 3V3 jumper in the J101
isolation block, and attach an ammeter across the 3V3 jumper.
- Consider the effect that the
backchannel UART and any circuitry attached to the MSPM0G3519 can have on the
current draw. Consider disconnecting the backchannel uart at the isolation
jumper block, or at least consider the current sinking and sourcing capability
in the final measurement.
- Make sure there are no floating
inputs or outputs (I/Os) on the MSPM0G3519. This causes unnecessary extra
current draw. Every I/O is either driven or, if the I/O is an input, is pulled
or driven to a high or low level.
- Begin target execution.
- For the most accurate current
measurements, place the device in Free Run mode and disconnect programming
signals between the MSPM0G3519 and the debug portion of the board (header
J101).
- Measure the current. Remember
that if the current levels are fluctuating, then getting a stable measurement
can be difficult. Measuring the quiescent states is easier.