Power Consumption Test Example — Screen Refresh Scenario

Source path: example/pm/lcd_refresh

Overview

This example measures the chip’s power consumption behavior during continuous LCD refresh activity.

Supported boards

sf32lb52-core_n16r16

Power measurement setup

Power the board as shown in the illustration; the supply pins are highlighted. Remove other jumper caps and keep the LDO5V jumper cap installed. Connect TXD and RXD to a serial adapter for input and control. alt text

Build and flash

Example (sf32lb52-core_n16r16): change to the example’s project/ directory and build with SCons:

scons --board=sf32lb52-core_n16r16 -j8

Flash using the provided batch script:

build_sf32lb52-core_n16r16_hcpu\uart_download.bat

Expected runtime behavior

After flashing and reset the system boots and the display shows a 200 × 228 alternating red/green flicker. On the power meter you should see a stable, periodic waveform with a ~16 ms refresh period. alt text

Test data (PVDD)

Condition: 16 ms per-frame refresh

Item	Duration	Current
Fill (buffer)	930 µs	10.2 mA
Submit / Display	15.6 ms	3.22 mA

Below are the delta-current calculations normalized to a 16.5 ms period:

Item	Calculation	Delta current
Delta for 930 µs fill	930 µs * 10.2 mA / 16.5 ms	0.57 mA
Delta for 15.6 ms submit	15.6 ms * 3.22 mA / 16.5 ms	3.04 mA

Total: 0.57 mA + 3.04 mA = 3.61 mA