MP8719 – 26V, 12A, HIGH-CURRENT, SYNC BUCK CONVERTER WITH ±1A LDO

MP8719 Rev1.01

www.MonolithicPower.com

19

8/3/2017

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Design Example

For applications that need currents over 10A, it

better thermal performance and efficiency (see

makes the system more compact with faster

transient (see Table 4).

There is a resistor from an external 3.3V supply

to 3V3 acting as a ripple noise filter of the 3.3V

power supply. It is recommended to have a

resistor value from 0 - 5.1Ω depending on the

noise level. A size 0402 resistor is sufficient if

the 3.3V voltage rises up with SS > 100µs.

Otherwise, a larger resistor (e.g.: 0603/0805) is

needed.

For applications where VIN is 5V or lower, it is

recommended to apply the SCH shown in

Figure 14 with a proper external ramp.

The

MP8719

also

supports

non

DDR

applications

with

very

compact

external

components (see Figure 15).

Some design examples are provided below

when ceramic capacitors are applied.

(V)

Cout

(F)

L

(μH)

(Ω)

C4

(pF)

R1

(kΩ)

R2

(kΩ)

1.0

22μx4

1.0

150k

220

13.3

20

1.2

22μx4

1.0

150k

220

20

20

1.35

22μx4

1.0

150k

220

28

22.1

1.5

22μx4

1.2

150k

220

30.1

20

1.8

22μx4

1.5

150k

220

40.2

20

(V)

Cout

(F)

L

(μH)

(Ω)

C4

(pF)

R1

(kΩ)

R2

(kΩ)

1

22μx3

0.68

0

220

13.3

20

1.2

22μx3

0.68

0

220

20

20

1.35

22μx3

0.68

0

220

28

22.1

1.5

22μx3

0.68

0

220

30.1

20

1.8

22μx3

0.68

0

220

40.2

20

Additional Design Examples with Higher

to be in the range of 3.3V to 5.5V. Figure 17

external settings. Please pay attention to the

red components, and please note that USM is

not allowed for this application.