Espressif Systems ESP32 Technical Reference Manual page 67

5 LED_PWM
5. LED_PWM
5.1 Introduction
The LED_PWM controller is primarily designed to control the intensity of LEDs, although it can be used to
generate PWM signals for other purposes as well. It has 16 channels which can generate independent
waveforms that can be used to drive e.g. RGB LED devices. For maximum flexibility, the high-speed as well as
the low-speed channels can be driven from one of four high-speed/low-speed timers. The PWM controller also
has the ability to automatically increase or decrease the duty cycle gradually, allowing for fades without any
processor interference. To increase resolution, the LED_PWM controller is also able to dither between two values
when a fractional PWM value is configured.
The LED_PWM controller has eight high-speed and eight low-speed PWM generators. In this document, they will
be referred to as hschn and lschn respectively. These channels can be driven from four timers, which will be
indicated by h_timerx and l_timerx.
5.2 Functional Description
5.2.1 Architecture
Figure 10: LED_PWM Architecture
Figure 10 shows the architecture of the LED_PWM controller. As can be seen from the figure, the LED_PWM
controller contains 8 high-speed and 8 low-speed channels. There are 4 high-speed clock modules for the
high-speed channels, from which one h_timerx can be selected. There are also 4 low-speed clock modules for
the low-speed channels, from which one l_timerx can be selected.
Figure 11: LED_PWM High-speed Channel Diagram
Espressif Systems 66 ESP32 Technical Reference Manual V1.0