WM8971L datasheet(47/61 Pages) WOLFSON

47 / 61 page

Production Data

WM8971L

PD Rev 4.1 August 2005

The WM8971L has two possible device addresses, which can be selected using the CSB pin.

CSB STATE

DEVICE ADDRESS

Low

0011010 (0 x 34h)

High

0011011 (0 x 36h)

Table 38 2-Wire MPU Interface Address Selection

POWER SUPPLIES

The WM8971L can use up to four separate power supplies:

•

AVDD / AGND: Analogue supply, powers all analogue functions except the headphone drivers.

AVDD can range from 1.8V to 3.6V and has the most significant impact on overall power

consumption (except for power consumed in the headphone). A large AVDD slightly improves

audio quality.

•

HPVDD / HPGND: Headphone supply, powers analogue outputs L/ROUT1, L/ROUT2 and

MONOOUT. HPVDD is normally tied to AVDD, but requires separate layout and decoupling

capacitors to curb harmonic distortion. If HPVDD is lower than AVDD, the output signal may be

clipped.

•

DCVDD: Digital core supply, powers all digital functions except the audio and control

interfaces. DCVDD can range from 1.42V to 3.6V, and has no effect on audio quality. The

return path for DCVDD is DGND, which is shared with DBVDD.

•

DBVDD: Digital buffer supply, powers the audio and control interface buffers. This makes it

possible to run the digital core at very low voltages, saving power, while interfacing to other

digital devices using a higher voltage. DBVDD draws much less power than DCVDD, and has

no effect on audio quality. DBVDD can range from 1.8V to 3.6V. The return path for DBVDD is

DGND, which is shared with DCVDD.

It is possible to use the same supply voltage on all four. However, digital and analogue supplies

should be routed and decoupled separately to keep digital switching noise out of the analogue signal

paths.

POWER MANAGEMENT

The WM8971L has two control registers that allow users to select which functions are active. For

minimum power consumption, unused functions should be disabled. To avoid any pop or click noise,

it is important to enable or disable functions in the correct order (see Applications Information).

VMIDSEL is the enable for the Vmid reference, which defaults to disabled and can be enabled as a

50kOhm potential divider or, for low power maintenance of Vref when all other blocks are disabled,

as a 500kOhm potential divider.

WM8971L датащи(PDF) 47 Page - Wolfson Microelectronics plc

WM8971L датащи(HTML) 47 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

датащи скачать

ссылки URL