DIO6905B

www.dioo.com

© 2025 Dioo Microcircuits Co., Ltd. Jiangsu

DIO6905B • Rev. 1.2

- 10 -

Application Information

Setting the output voltage

The external resistor divider sets the output voltage. Select the feedback resistor R1 which reduces the VOUT

leakage current, typically between 40 kΩ to 200 kΩ. There is no strict requirement for the feedback resistor. R1 >

10 kΩ is reasoned for most applications. R2 can be calculated with Equation (2):

1

0.6

V

R1

R2

OUT 



(2)

The feedback circuit is shown in Figure 2:

Figure 2. Feedback network

Table 1 lists the recommended values of resistors for common output voltages:

Table 1. Resistor values for common output voltages

VOUT (V)

R1 (kΩ)

R2 (kΩ)

L (μH)

COUT (μF)

Cff (pF)

1.2

200

200

2.2

10

47

1.8

200

100

2.2

10

47

2.5

200

63.2

2.2

10

47

3.3

200

44.2

2.2

10

47

4.2

200

33

2.2

10

47

Selecting the inductor

Most applications work best with a 1 µH to 2.2 µH inductor. Select an inductor with a DC resistance of less than

15 mΩ to optimize efficiency.

A high-frequency switch-mode power supply with a magnetic device has strong electronic magnetic inference.

Avoid using unshielded power inductors. Metal alloy or multiplayer chip power inductors are ideal shielded

inductors for the application because they can decrease the influence effectively. Table 2 lists some

recommended inductors.

Table 2. Recommended inductors

Manufacturer P/N

Inductance (μH)

Manufacturer

744 777 002

2.2

Wurth