1. From the power supply point of view, after 3.6V and 5V are connected in series, an 8.5V power supply is obtained, followed by a voltage reference device. The disadvantage of this application is that the two power supplies cannot be used separately.
2. The advantage of using DC/DC converter circuit is high power output, but the disadvantage is high cost.
3. Using charge pump and other voltage doubling circuits has the advantages of low cost and low output power. Since you are a reference and don't need high power, this shortcoming does not exist.
4. The switch-type voltage stabilizing chip (actually DC/DC) is adopted, and there are three-terminal voltage stabilizing blocks, similar to 7805. Its advantages are simple use.
The above circuit has only one purpose, that is, boosting the voltage. As the reference voltage source of ADC and DAC, it needs high accuracy and stability. After the above circuits are connected with special voltage reference chips such as MAX6225 and MAX624 1, the accuracy can reach 0.02%.