WM9010

Production Data

w

PD, February 2011, Rev 4.0

8

CHARGE PUMP

The WM9010 incorporates a charge pump circuit, which generates the supply rails for the

headphone output drivers. The charge pump is powered from VDD, and generates split rails

CPVOUTP and CPVOUTN. The circuit is adaptive according to the audio signal conditions,

supporting the Class G operation and ensuring optimum circuit configuration at all times. The

switching clock for the charge pump is generated internally.

The external connections for the charge pump are illustrated in Figure 2. A fly-back capacitor is

connected between the CPCA and CPCB pins. De-coupling capacitors are required on CPVOUTP

and CPVOUTN. An input decoupling capacitor may also be required at VDD, depending upon the

system configuration.

Figure 2 External Connections for Charge Pump