WM8962B datasheet(131/295 Pages) WOLFSON

131 / 295 page

WM8962

Rev 4.3

131

outputs, suppressing ‘pop’ noise and minimising power consumption. The Charge Pump and DC

Servo are described separately (see “Charge Pump” and “DC Servo” respectively).

It is recommended to connect a zobel network to the headphone output pins HPOUTL and HPOUTR

for best audio performance in all applications. The components of the zobel network have the effect of

dampening high frequency oscillations or instabilities that can arise outside the audio band under

certain conditions. Possible sources of these instabilities include the inductive load of a headphone

coil or an active load in the form of an external line amplifier. The capacitance of lengthy cables or

PCB tracks can also lead to amplifier instability. The zobel network should comprise of a 20

 resistor

and 100nF capacitor in series with each other, as illustrated in Figure 36.

Note that the zobel network may be unnecessary in some applications; it depends upon the

characteristics of the connected load. It is recommended to include these components for best audio

quality and amplifier stability in all cases.

AGND = 0V

WM8962

20Ω

100 nF

AGND = 0V

HPOUTL

HPOUTR

HPOUTFB

20Ω

100 nF

Figure 36 Zobel Network Components for HPOUTL and HPOUTR

The headphone output incorporates a common mode, or ground loop, feedback path which provides

rejection of system-related ground noise. The return path is via HPOUTFB. This pin must be

connected to ground for normal operation of the headphone output. No register configuration is

required.

CHARGE PUMP

The WM8962 incorporates a dual-mode Charge Pump which generates the supply rails for the

headphone output drivers, HPOUTL and HPOUTR. The Charge Pump has a single supply input,

CPVDD, and generates split rails CPVOUTP and CPVOUTN according to the selected mode of

operation. The Charge Pump connections are illustrated in Figure 37 (see

“Electrical Characteristics”

for external component values). An input decoupling capacitor may also be required at CPVDD,

depending upon the system configuration.

CPVDD

WM8962

Charge Pump

CPVOUTP

CPVOUTN

CPCA

CPCB

CPGND

Figure 37 Charge Pump External Connections

WM8962B Datasheet(PDF) 131 Page - Wolfson Microelectronics plc

WM8962B Datasheet(HTML) 131 Page - Wolfson Microelectronics plc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL