WM8352 datasheet(142/336 Pages) WOLFSON

142 / 336 page

WM8352

Production Data

PD, February 2011, Rev 4.4

142

14.8.3

DC-DC STEP UP CONVERTERS

DC-DC Converters 2 and 5 are versatile step-up pulse-width-modulated (PWM) DC-DC converters

designed to deliver high power efficiency across full load conditions. The converters can also be

used as switches.

DC-DC Converters 2 and 5 are designed with a fixed frequency current mode architecture. The clock

frequency is set by the internal RC oscillator, which provides a 1.0MHz clock.

The PVDD supply pin provides the core supply for DC-DC Converter 2. The LINEDCDC supply pin

provides the core supply for DC-DC Converter 5.

The connections to DC-DC Converter 2 in Constant Voltage Mode are illustrated in Figure 70. The

equivalent circuit applies to DC-DC Converter 5 also. See Section 29.4 for details of the connections

for the Constant Current and USB operating modes of the DC-DC Step-Up Converters.

Figure 70 Step-Up DC-DC Converter Connections

The external components at the converter output are required by the DC-DC Converter integral loop

compensation circuit. Note that the recommended output capacitor Cout varies according to the

required output voltage.

See Section 29.4 for details of the recommended external components.

WM8352 Datasheet(PDF) 142 Page - Wolfson Microelectronics plc