WM8352
Production Data
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.
PD, February 2011, Rev 4.4
142
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