WM8978_06 Wolfson Microelectronics Ltd., WM8978_06 Datasheet - Page 40
WM8978_06
Manufacturer Part Number
WM8978_06
Description
Stereo Codec With Speaker Driver
Manufacturer
Wolfson Microelectronics Ltd.
Datasheet
1.WM8978_06.pdf
(119 pages)
- Current page: 40 of 119
- Download datasheet (2Mb)
WM8978
INPUT LIMITER / AUTOMATIC LEVEL CONTROL (ALC)
w
The WM8978 has an automatic PGA gain control circuit, which can function as an input peak limiter
or as an automatic level control (ALC).
the amplitude of the input signal. A digital peak detector monitors the input signal amplitude and
compares it to a register defined threshold level (ALCLVL).
If the signal is below the threshold, the ALC will increase the gain of the PGA at a rate set by
ALCDCY. If the signal is above the threshold, the ALC will reduce the gain of the PGA at a rate set
by ALCATK.
The ALC has two modes selected by the ALCMODE register: normal mode and peak limiter mode.
The ALC/limiter function is enabled by setting the register bit R32[8] ALCSEL.
The Automatic Level Control (ALC) provides continuous adjustment of the input PGA in response to
R32 (20h)
ALC Control
1
R33 (21h)
ALC Control
2
REGISTER
ADDRESS
2:0
5:3
8:7
3:0
BIT
ALCMIN
[2:0]
ALCMAX
[2:0]
ALCSEL
ALCLVL
[3:0]
LABEL
000 (-12dB)
111
(+35.25dB)
00
1011
(-6dB)
DEFAULT
Set minimum gain of PGA
000 = -12dB
001 = -6dB
010 = 0dB
011 = +6dB
100 = +12dB
101 = +18dB
110 = +24dB
111 = +30dB
Set Maximum Gain of PGA
111 = +35.25dB
110 = +29.25dB
101 = +23.25dB
100 = +17.25dB
011 = +11.25dB
010 = +5.25dB
001 = -0.75dB
000 = -6.75dB
ALC function select
00 = ALC disabled
01 = Right channel ALC enabled
10 = Left channel ALC enabled
11 = Both channels ALC enabled
ALC target – sets signal level at ADC
input
1111 = -1.5dBFS
1110 = -1.5dBFS
1101 = -3dBFS
1100 = -4.5dBFS
1011 = -6dBFS
1010 = -7.5dBFS
1001 = -9dBFS
1000 = -10.5dBFS
0111 = -12dBFS
0110 = -13.5dBFS
0101 = -15dBFS
0100 = -16.5dBFS
0011 = -18dBFS
0010 = -19.5dBFS
0001 = -21dBFS
0000 = -22.5dBFS
DESCRIPTION
PP Rev 3.0 May 2006
Pre-Production
40
Related parts for WM8978_06
Image
Part Number
Description
Manufacturer
Datasheet
Request
R
Part Number:
Description:
The WM8978 is a low power, high quality stereo codec designed for portable applications such as Digital still camera or Digital Camcorde
Manufacturer:
Wolfson Microelectronics Ltd.
Datasheet:
Part Number:
Description:
Specifications: Manufacturer: Wolfson Microelectronics ; Product Category: ADC (A/D Converters) ; RoHS: Details ; Number of Converters: 1 ; Number of ADC Inputs: 1 ; Conversion Rate: 6 MSPs ; Resolution: 16 bit ; Input Type: Voltage ; Interface
Manufacturer:
Wolfson Microelectronics Ltd.
Datasheet:
Part Number:
Description:
Manufacturer:
Wolfson Microelectronics Ltd.
Datasheet:
Part Number:
Description:
Manufacturer:
Wolfson Microelectronics Ltd.
Datasheet:
Part Number:
Description:
Manufacturer:
Wolfson Microelectronics Ltd.
Datasheet:
Part Number:
Description:
Manufacturer:
Wolfson Microelectronics Ltd.
Datasheet:
Part Number:
Description:
Manufacturer:
Wolfson Microelectronics Ltd.
Datasheet:
Part Number:
Description:
WM8192 : 16-BIT, 6MSPS Cis/ccd Image Digitiser With Multiplexed Output
Manufacturer:
Wolfson Microelectronics Ltd.
Datasheet:
Part Number:
Description:
The WM8976 is a low power, high quality stereo codec designed for portable applications such as Digital still camera or Digital Camcorde
Manufacturer:
Wolfson Microelectronics Ltd.
Datasheet:
Part Number:
Description:
WM8141 : 12-BIT 6MSPS Cis/ccd Analogue Front End/digitiser
Manufacturer:
Wolfson Microelectronics Ltd.
Datasheet:
Part Number:
Description:
WM8143 : 10 or 12-BIT, 4MSPS Analogue Front End For CCD Image Sensors
Manufacturer:
Wolfson Microelectronics Ltd.
Datasheet:
Part Number:
Description:
WM8143 : 10 or 12-BIT, 4MSPS Analogue Front End For CCD Image Sensors
Manufacturer:
Wolfson Microelectronics Ltd.
Datasheet:
Part Number:
Description:
Integrated 10-bit Data Acquisition System For Imaging Applications
Manufacturer:
Wolfson Microelectronics Ltd.
Datasheet:
Part Number:
Description:
12-bit ( 8+4-bit ) Linear Sensor Image Processor
Manufacturer:
Wolfson Microelectronics Ltd.
Datasheet:
Part Number:
Description:
WM8148 : 12-BIT/12 MSPS Ccd/cis Analogue Front End/digitiser
Manufacturer:
Wolfson Microelectronics Ltd.
Datasheet: