AN2815 datasheet(14/42 Pages) STMICROELECTRONICS

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Configuration

AN2815

14/42

Configuration

The PM6675AS demonstration board allows the user to choose the desired mode of

operation using four jumpers (JP1, JP2, JP3 and JP5) and two resistors. Refer to the

following configuration description.

6.1

JP3 fixed or adjustable output voltage (VSEL pin)

The JP3 jumper is used to choose between fixed output voltage (1.5 V) and a user-defined

output voltage in the range 0.6 V to 3.3 V. When connected in the lower position, the fixed

1.5 V output voltage is selected (Figure 8).

If JP3 is in the upper position, the output voltage is given by:

Equation 1

The R8 and R9 resistors are set to 12 k

Ω and 13 kΩ respectively (1.25 V output voltage)

and can be changed by the user.

6.2

JP1 power-saving mode (NOSKIP pin)

The JP1 jumper allows choosing the mode of operation of the switching section. Three

options (forced-PWM, pulse-skip and non-audible pulse-skip) can be selected by changing

the JP1 setting as shown in Figure 9:

Figure 9.

JP3 (VSEL) setting

VOUTADJ

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AN2815 Datasheet(PDF) 14 Page - STMicroelectronics