AN3302

Recommended PCB Iayout

Doc ID 18163 Rev 1

5/13

2.2

Programming the output voltage

The output voltage for the step-up (ch1) can be adjusted from 6.5 V up to 14 V by

must be connected to the FB1 pin, as shown in Figure 2.

The resistor divider should be chosen according to the following equation:

Equation 1

Figure 11

).

It is recommended to use a resistor with a value in the range of 1 k

Ω to 50 kΩ. Lower values

may also be suitable, but increase current consumption.

For ch2 the device integrates the resistor divider needed to set the correct output voltage

(3.3 V). This allows to save 2 external components. The FB2 pin must be connected directly

The output voltage for ch3 can be adjusted from 0.8 V up to 94 % of the input voltage value

must be connected to the FB3 pin, as shown in Figure 2.

The resistor divider should be chosen according to the following equation:

Equation 2

It is recommended to use a resistor with a value in the range of 1 k

Ω to 50 kΩ. Lower values

may also be suitable, but increase current consumption.

⎟⎟

⎠

⎞

⎜⎜

⎝

⎛

+

⋅

=

1

R

R

V

V

2

1

1

FB

1

OUT

⎟⎟

⎠

⎞

⎜⎜

⎝

⎛

+

⋅

=

1

R

R

V

V

4

3

3

FB

3

OUT