An example of regulating the current of a boost power supply in an LED string

An example of regulating the current of a boost power supply in an LED string

In this configuration, the peripheral is configured as a fixed frequency power supply that generates most current modes. COG is a complementary output generator. Its function is to generate complementary outputs through a programmable dead zone composed of rising and falling edge inputs. CCP is configured to generate programmable frequency rise edges. When the current exceeds the output of the slope compensator, comparator C1 generates a falling edge. CCP can be combined with C1 to generate a duty cycle. Some topologies, such as boost, flyback, or SEPIC, require a duty cycle. The operational amplifier OPA is used to provide feedback and compensation. The DAC in the figure provides a reference voltage for the operational amplifier, but if programmable voltage is not required, a fixed voltage reference (FVR) can also be used to provide a reference voltage for the operational amplifier. The slope compensator can be reset through a comparator or COG. Its working principle is to use programmable charging current to attenuate the capacitor that is pre charged to the level set by its input (in this case OPA). This power configuration is very easy to use. The following is an example of adjusting the current of the boost power supply in the LED string.

Example of Boost LED Power Supply

After building and testing the hardware, simply implementing some basic functions can increase intelligence, as shown below:

LED driver flowchart

功率点状态机

Battery charger status machine

conclusion

The termination effect obtained by adding to the power supply is much stronger than when using the device alone. Integration can take the following forms: simply connect the MCU to the existing SMPS design, establish a fully digital SMPS through high-performance dsPIC, or integrate analog SMPS functions with the MCU on a single chip using a mixed signal MCU.