DESCRIPTION
The WM8816 is a highly linear stereo volume control for audio systems. The design is based on resistor chains with external op-amps, which provides flexibility for the supply voltage, signal swing, noise floor and cost optimisation. The gain of each channel can be independently programmed from -111.5dB to +15.5dB through a digital serial control interface.
Audible clicks on gain changes are eliminated by changing gains only when a zero crossing has been detected in the signal. The device also features peak level detection, which can be used for Automatic Gain Control. The WM8816 operates from a single +5V supply and accepts signal input levels up to ±18V.
The WM8816 is available in a 16-pin SOIC package. It is guaranteed over a temperature range of -40° to 85°C.
WM8816
Stereo Digital Volume Control
Advanced Information, September 2000, Rev 1.1
FEATURES
• Gain range from -111.5dB to +15.5dB • 0.5dB Gain step size • Total Harmonic Distortion 0.001% (100dB) typical • Crosstalk -110dB typical • Input signals up to ±18V • Zero Detection for Gain Changes • Hardware and Software Mute • Power On/Off Transient Suppression
APPLICATIONS
• Audio Amplifiers • Consumer Audio / Entertainment Systems • Mixing Desks • Audio Recording Equipment
BLOCK DIAGRAM
LIN (4) LGND (5)
Zero Crossing Detector
Peak Level Detector
(3) LFO
(2) LMO
+
LEFT OUT
CSB (6) MUTEB (8)
DATA (9) CCLK (10)
WM8816
Control
DAC
External Opamps
RGND (12) RIN (13)
Zero Crossing Detector
Peak Level Detector
(15) RMO
+ -
(14) RFO
RIGHT OUT
(1) AVDD
(16) AGND
(7) DVDD
WOLFSON MICROELECTRONICS LTD
Lutton Court, Bernard Terrace, Edinburgh, EH8 9NX, UK Tel: +44 (0) 131 667 9386 Fax: +44 (0) 131 667 5176 Email:
[email protected] http://www.wolfson.co.uk
(11) DGND
Advanced information data sheets contain preliminary data on new products in the pre-production phase of development.
Supplementary data will be published at a later date.
2000 Wolfson Microelectronics Ltd.
WM8816 PIN CONFIGURATION
AVDD LMO LFO LIN LGND CSB
DVDD MUTEB
1 2 3 4 5 6 7 8
16 AGND 15 RMO 14 RFO 13 RIN 12 RGND 11 DGND 10 CCLK
9 DATA
Advanced Information
ORDERING INFORMATION
DEVICE XWM8816EDW
TEMP. RANGE -40 to +85oC
PACKAGE 16-pin SOIC (plastic)
PIN DESCRIPTION
PIN NAME
TYPE
DESCRIPTION
1 AVDD
Supply
Supply Voltage for Analogue Circuitry
2
LMO
Analogue Output External Op-amp Inverting Input (Left Channel)
3 LFO Analogue Input External Op-amp Feedback Signal (Left Channel)
4 LIN Analogue Input Input Signal (Left Channel)
5
LGND
Analogue Input Input Signal Ground (Left Channel)
6
CSB
Digital Input
Chip Select (active low)
7 DVDD
Supply
Supply Voltage for Digital Circuitry
8
MUTEB
Digital Input
Mute (active low)
9
DATA
Digital In / Out Serial Interface Data Input / Output (tri-state)
10
CCLK
Digital Input
Serial Interface Clock
11 DGND
Supply
Digital Ground
12
RGND
Analogue Input Input Signal Ground (Right Channel)
13 RIN Analogue Input Input Signal (Right Channel)
14
RFO
Analogue Input External Op-amp Feedback Signal (Right Channel)
15
RMO
Analogue Output External Op-amp Inverting Input (Right Channel)
16 AGND
Supply
Analogue Ground
WOLFSON MICROELECTRONICS LTD
AI Rev 1.1 September 2000
2
Advanced Information
WM8816
ABSOLUTE MAXIMUM RATINGS
Absolute Maximum Ratings are stress ratings only. Permanent damage to the device may be caused by continuously operating at or beyond these limits. Device functional operating limits and guaranteed performance specifications are given under Electrical Characteristics at the test conditions specified.
ESD Sensitive Device. This device is manufactured on a CMOS process. It is therefore susceptible to damage from excessive static voltages. To optimise the distortion and noise performance of pins 3, 4, 13 and 14, the on-chip ESD protection circuitry has been restricted, and consequently only achieves 300V when characterised to the Human Body Model. Proper ESD precautions must be taken during handling and storage of this device.
As per JEDEC specification JESD22-A112-A, this product requires specific storage conditions prior to surface mount assembly. It has been classified as having a Moisture Sensitivity Level of 3 and is therefore supplied in vacuum-sealed moisture barrier bags.
CONDITION Input signal voltage Positive supply voltage (AVDD to AGND, DVDD to DGND) Input voltage (all other pins) Operating temperature Storage temperature
MIN -20V -0.5V -0.5V -40°C -55°C
MAX +20V
6V AVDD + 0.5V
85°C 125°C
RECOMMENDED OPERATING CONDITIONS
PARAMETER
Input signal voltage Positive supply voltage Negative supply voltage Input signal grounds Operating temperature
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNIT
AVDD, DVDD AGND, DGND LGND, RGND
-18 +18 V 4.5 5 5.5 V
0V 0V -20 60 60 °C
ELECTRICAL CHARACTERISTICS
TEST CONDITIONS
AVDD = 5.0V, AGND = 0V, TA = 25°C, unless otherwise stated.
PARAMETER
SYMBOL TEST CONDITIONS
MIN
TYP
MAX
UNIT
Analogue Inputs / Outp.