WM8950 ADC with Microphone Input and Programmable Digital Filters DESCRIPTION FEATURES Mono ADC: The WM8950 is a low power, high quality mono ADC designed Audio sample rates:8, 11.025, 16, 22.05, 24, 32, 44.1, 48kHz for portable applications such as Digital Still Camera, Digital SNR 94dB, THD -83dB (A-weighted 8 48ks/s) Voice Recorder or games console accessories. Multiple auxiliary analogue inputs The device integrates support for a differential or single ended Mic Preamps: mic. External component requirements are reduced as no Differential or single end Microphone Interface separate microphone amplifiers are required. - Programmable preamp gain - Pseudo differential inputs with common mode rejection Advanced Sigma Delta Converters are used along with digital - Programmable ALC / Noise Gate in ADC path decimation filters to give high quality audio at sample rates Low-noise bias supplied for electret microphones from 8 to 48ks/s. Additional digital filtering options are available, to cater for application filtering such as wind noise OTHER FEATURES reduction, noise rejection, plus an advanced mixed signal ALC 5 band EQ function with noise gate is provided. Programmable High-Pass Filter (wind noise reduction) Fully Programmable IIR Filter (notch filter) An on-chip PLL is provided to generate the required Master On-chip PLL Clock from an external reference clock. The PLL clock can Low power, low voltage also be output if required elsewhere in the system. - 2.5V to 3.6V (digital: 1.71V to 3.6V) The WM8950 operates at supply voltages from 2.5 to 3.6V, - power consumption 10mA all-on 48ks/s mode although the digital supplies can operate at voltages down to 4x4x0.9mm 24 lead QFN package 1.71V to save power. Different sections of the chip can also be APPLICATIONS powered down under software control by way of the selectable two or three wire control interface. Digital Still Camera General Purpose low power audio ADC WM8950 is supplied in a very small 4x4mm QFN package, Games console accessories offering high levels of functionality in minimum board area, with Voice recorders high thermal performance. DCVDD DBVDD DGND AGND2 AVDD2 20k AUX WM8950 20k analog inputs Gains: -12dB to +35.25dB NOISY GND MICN 2 FRAME I S or ADC Programmable IIR Filter with 5 Band ADC Digital High Pass Programmable PCM ADCDAT EQ Filters Filter Coefficients Interface BCLK Mic IP PGA IP BOOST/MIX MICP TP Rbias Automatic Level Control DSP Core CONTROL MICBIAS PLL 50k 50k INTERFACE 4k 5k 500k 500k Rev 4.5 Copyright Cirrus Logic, Inc., 2005 2016 AUG 16 WM8950 TABLE OF CONTENTS DESCRIPTION ....................................................................................................... 1 FEATURES ............................................................................................................ 1 APPLICATIONS ..................................................................................................... 1 TABLE OF CONTENTS ......................................................................................... 2 PIN CONFIGURATION .......................................................................................... 3 ORDERING INFORMATION .................................................................................. 3 PIN DESCRIPTION ................................................................................................ 4 ABSOLUTE MAXIMUM RATINGS ........................................................................ 5 RECOMMENDED OPERATING CONDITIONS ..................................................... 5 ELECTRICAL CHARACTERISTICS ..................................................................... 6 TERMINOLOGY ............................................................................................................... 7 SIGNAL TIMING REQUIREMENTS ...................................................................... 8 SYSTEM CLOCK TIMING ................................................................................................ 8 AUDIO INTERFACE TIMING MASTER MODE ............................................................ 8 AUDIO INTERFACE TIMING SLAVE MODE ................................................................ 9 CONTROL INTERFACE TIMING 3-WIRE MODE ....................................................... 10 CONTROL INTERFACE TIMING 2-WIRE MODE ....................................................... 11 DEVICE DESCRIPTION ...................................................................................... 12 INTRODUCTION ............................................................................................................ 12 INPUT SIGNAL PATH .................................................................................................... 13 ANALOGUE TO DIGITAL CONVERTER (ADC) ............................................................ 18 INPUT AUTOMATIC LEVEL CONTROL (ALC) ............................................................. 22 DIGITAL AUDIO INTERFACES ..................................................................................... 36 AUDIO SAMPLE RATES ................................................................................................ 41 MASTER CLOCK AND PHASE LOCKED LOOP (PLL) ................................................. 42 GENERAL PURPOSE INPUT/OUTPUT ........................................................................ 44 CONTROL INTERFACE ................................................................................................. 44 RESETTING THE CHIP ................................................................................................. 45 POWER SUPPLIES ....................................................................................................... 46 ADC POWER UP/DOWN SEQUENCE .......................................................................... 46 POWER MANAGEMENT ............................................................................................... 47 REGISTER MAP .................................................................................................. 49 DIGITAL FILTER CHARACTERISTICS .............................................................. 50 TERMINOLOGY ............................................................................................................. 50 ADC FILTER RESPONSES ........................................................................................... 50 DE-EMPHASIS FILTER RESPONSES .......................................................................... 51 HIGH-PASS FILTER ...................................................................................................... 52 5-BAND EQUALISER ..................................................................................................... 53 APPLICATIONS INFORMATION ........................................................................ 57 RECOMMENDED EXTERNAL COMPONENTS ............................................................ 57 PACKAGE DIAGRAM ......................................................................................... 58 IMPORTANT NOTICE ......................................................................................... 59 REVISION HISTORY ........................................................................................... 60 2 Rev 4.5