MP2316 Rev. 1.11

www.MonolithicPower.com

17

4/11/2017

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APPLICATION INFORMATION

COMPONENT SELECTION

Setting the Output Voltage

The external resistor divider is used to set the

output voltage. First, choose a value for R2. R2

should be chosen reasonably, a small R2 will

lead to considerable quiescent current loss

while too large R2 makes the FB noise

sensitive. It is recommended to choose a value

within for R2. Typically, set the current through

R2 between will make a good balance between

system stability and also the no load loss. Then

R1 is determined as follow:

OUT

REF

REF

VV

R1

R2

V





(11)

The feedback circuit is shown as Figure 9.

Figure 9—Feedback Network

Table 2 lists the recommended resistors value

for common output voltages.

Table 2—Resistor Selection for Common

R1(kΩ)

R2(kΩ)

1.0

27

40.2

1.2

40.2

40.2

1.5

60.4

40.2

1.8

80.6

40.2

2.5

127

40.2

3.3

182

40.2

5

294

40.2

Notes:

10) The feedback resistors in table 2 are optimized for 500kHz

switching frequency. The detailed schematics are shown on

the typical application circuit section.

Setting the Frequency

Refer to Mode selection section. Set the forced

PWM mode switching frequency by connecting

a resistor R6 from VIN to FREQ/MODE pin and

leaving R7 NS. The R6 is determined as follows:



6

Delay _ PWM

IN

SW

IN

Vo 10

T

(ns)

V

0.4

F(kHz) V

R6(k )

14.5

















(12)

Figure 10—R6 vs. Forced PWM Mode

Switching Frequency

Set the auto PFM/PWM mode switching

frequency by connecting a resistor R7 from

FREQ/MODE pin to ground and leaving R6 NS.

The R7 is determined as follow:



6

Delay _ PFM

IN

SW

IN

Vo 10

T

(ns)

V

0.4

F(kHz) V

R7(k )

13

















(13)

Figure 11—R7 vs. Auto PFM/PWM Mode

Switching Frequency