4.4 Low-Power Measurement

Power to the PIC16F17146 comes from the on-board power supply and VTG pin through a 100 mil pin-header marked with “POWER” in silkscreen (J101). To measure the power consumption of the PIC16F17146 and other peripherals connected to the board, cut the Target Power strap and connect an ammeter across it.

To measure the lowest possible power consumption, follow these steps:
  1. Cut the POWER strap with a sharp tool.
  2. Solder a 1x2 100 mil pin-header in the footprint.
  3. Connect an ammeter to the pin header.
  4. Write firmware that:
    1. Tri-states any I/O connected to the on-board debugger.
    2. Sets the microcontroller in its lowest Power sleep mode.
  5. Program the firmware into the PIC16F17146.
Figure 4-7. Target Power Strap
Tip: A 100-mil pin-header can be soldered into the Target Power strap (J101) footprint for a simple connection of an ammeter. Place a jumper cap on the pin-header once the ammeter is no longer needed.
Info: The on-board level shifters will draw a small amount of current even when unused. Each level shifter has maximum of 2 μA leakage current. Therefore, the worst-case maximum current draw for the five on-board level shifters is 10 μA. Prevent leakage current through an I/O pin connected to a level shifter by keeping the I/O pin tri-stated. All I/Os connected to the on-board debugger are listed in 5.2.4.1 On-Board Debugger Connections. The on-board level shifters can be completely disconnected, preventing leakage, as described in 8.4 Disconnecting the On-Board Debugger.