WM8952ECSSLASHRV datasheet(29/72 Pages) WOLFSON

部件名	WM8952ECS/RV

功能描述	Mono ADC with Microphone Pre-amplifier

PDF	72 Pages

Scroll/Zoom	100%

制造商	WOLFSON [Wolfson Microelectronics plc]

网页	http://www.wolfsonmicro.com

标志

29 / 72 page

Pre Production

WM8952

PP, Rev 3.1, June 2011

ADDRESS

BIT

LABEL

DEFAULT

DESCRIPTION

R42 (2Ah)

ALC Control 4

ALCZC

0 (zero cross

off)

ALC uses zero cross detection circuit.

0 = Disabled (recommended)

1 = Enabled

Table 20 ALC Control Registers

When the ALC is disabled, the input PGA remains at the last controlled value of the ALC. An input

gain update must be made by writing to the INPPGAVOLL/R register bits.

If there is no analogue input signal present when the ALC is enabled, the ALC may not function

correctly. To ensure correct operation of the ALC with no analogue input signal, the Input PGA

Volume control register (R45) should be written with the INPPGAMUTE and ALCZC bits set to 0

before setting the ALCSEL bit to 1 in register R32 (bit 8).

NORMAL MODE

In normal mode, the ALC will attempt to maintain a constant signal level by increasing or decreasing

the gain of the PGA. The following diagram shows an example of this.

Figure 12 ALC Normal Mode Operation

WM8952ECS/RV 数据表(PDF) 29 Page - Wolfson Microelectronics plc