DIO6971

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© 2018 DIOO MICROCIRCUITS CO., LTD

DIO6971• V1.1

 

Application Information

DIO6971 is a synchronous buck regulator IC that integrates the COT control, top and bottom switches on the

same die to minimize the switching transition loss and conduction loss. With ultra low RDS(ON) power switches

and proprietary COT control, this regulator IC can achieve the highest efficiency and the highest switch

frequency simultaneously to minimize the external inductor and capacitor size, and thus achieving the

minimum solution footprint.

Because of the high integration in the DIO6971 IC, the application circuit based on this regulator IC is rather

simple. Only input capacitor CIN, output capacitor COUT, output inductor L and feedback resistors (R1 and R2)

need to be selected for the targeted applications specifications.

Feedback resistor dividers R1 and R2

Choose R1 and R2 to program the proper output voltage. To minimize the power consumption under light

loads, it is desirable to choose large resistance values for both R1 and R2. A value of between 10k and 1M is

highly recommended for both resistors. If VOUT is 3.3V, R1=40.2k is chosen, then R2 can be calculated to be

13k.

R2=

1

8

.

0

8

.

0

R

V

V

V

OUT



Input capacitor CIN

This ripple current through input capacitor is calculated as:

ICIN_RMS=IOUT

)

1

(

D

D





This formula has a maximum at VIN=2VOUT condition, where ICIN_RMS=IOUT/2. This simple worst-case condition is

commonly used for DC/DC design.

To minimize the potential noise problem, place a typical X5R or better grade ceramic capacitor really close to

the IN and GND pins. Care should be taken to minimize the loop area formed by CIN, and IN/GND pins. In this

case, a 10μF low ESR ceramic capacitor is recommended.

Output capacitor COUT

The output capacitor is selected to handle the output ripple noise requirements. Both steady state ripple and

transient requirements must be taken into consideration when selecting this capacitor. For the best

performance, it is recommended to use X5R or better grade ceramic capacitor greater than 22µF capacitance.