This application note provides detailed guidance on optimizing power consumption for battery-powered applications using HDSC HC32L series ultra-low power MCUs.

Understanding Power Modes

the HC32L series offers multiple power modes to balance functionality with power consumption:

Active Mode

  • CPU running at full speed
  • All peripherals available
  • Current: ~100μA/MHz typical

Sleep Mode

  • CPU clock stopped
  • Peripherals continue operating
  • Fast wake-up for interrupts
  • Current: ~30μA/MHz

Deep Sleep Mode

  • Main clock stopped
  • LPO running, RTC active
  • RAM retained
  • Current: 0.5μA with RTC

Shutdown Mode

  • All clocks stopped
  • Only wakeup pin active
  • Current: 0.15μA

Power Optimization Techniques

1. Clock Gating

Disable clocks to unused peripherals to save power.

2. GPIO Configuration

Unused pins should be configured to minimize leakage.

3. Peripheral Management

  • Disable ADC between conversions
  • Use DMA instead of CPU polling
  • Lower UART baud rate when possible

4. Efficient Wake-up Strategy

  • Use RTC for periodic wake-up
  • Configure appropriate wake-up sources
  • Minimize time in active mode

Measuring Power Consumption

accurate measurement requires:

  • Use high-precision multimeter
  • Measure current in series
  • Account for regulator efficiency
  • Consider temperature effects

    • LiTong provides a power calculator tool.