PDF NAU85L20 Data sheet ( Hoja de datos )

Número de pieza	NAU85L20
Descripción	Dual Audio ADC
Fabricantes	nuvoton
Logotipo
Hay una vista previa y un enlace de descarga de NAU85L20 (archivo pdf) en la parte inferior de esta página. Total 30 Páginas
No Preview Available ! NAU85L20 Data Sheet NAU85L20 Dual Audio ADC with Integrated FLL and Microphone Preamplifier Description The NAU85L20 is a low power, high quality, 2-channel ADC for microphone array application. The NAU85L20 integrates programmable gain preamplifiers for stereo differential microphones, significantly reducing external component requirements. A fractional FLL is available to accurately generate any audio sample rate using any commonly available system clock source from 8KHz through 33MHz. Audio data can be directed to I2S data out lines. The NAU85L20 operates with analog supply voltages from 1.6V to 2V, while the digital core can operate down to 1.2V to conserve power. Internal register controls enable flexible power saving modes by powering down sub- sections of the chip under software control. The NAU85L20 is specified for operation from -40°C to +85°C, and is available in a 28-lead QFN package. Features  101dB SNR (A-weighted) @ 0dB gain,  Supports sample rates from 8 kHz to 48 kHz at 24- VDDA=1.8V, Fs = 48 kHz, OSR=128x  91dB THD+N @ 0dB gain, 0.8Vrms in, VDDA=1.8V, Fs=48 kHz, OSR=128x  -124dB Channel Crosstalk @ 0dB gain, 0.9Vrms in, VDDA=1.8V, Fs=48 kHz, OSR=128x  Integrated programmable gain microphone amplifier  On-chip FLL  I2C Serial control interface with read/write bit resolution  Two separate microphone bias supplies for low noise microphone biasing.  Standard audio data bus interfaces: I2S, Left or Right justified, Two’s compliment, MSB first  32-bit audio sub frames  Package: Pb free 28L-QFN  Temperature range: -40 to 85° capability Block Diagram MIC1P MIC1N MIC2P MIC2N MICBIAS1 MICBIAS2 ADC Digital Core HPF NF ADC ALC u/A Law Compression MICBIAS 1 MICBIAS 2 FLL Audio Interface I2S/PCM BCLK FS DO12 I2C/SPI SCLK SDIO CSB MODE Nuvoton Technology Corporation America Tel: 1-408-544-1718 Fax: 1-408-544-1787 Rev. 0.1.6: May 10, 2016 1 1 page Pin Description Pin # 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Name MIC2P/LIN2 MIC2N VREF MICREF VDDC VSSD VDDB MCLKO NC DO12 BCLK FS MCLKI CSB SCL SDA MODE 18 VDDA 19 VSSA 20 MIC1N 21 MIC1P/LIN1 22 NC 23 NC 24 MICBIAS1 25 MICVDD 26 MICBIAS2 27 NC 28 NC NAU85L20 Type Analog Input Analog Input Reference Analog Output Supply Supply Supply Digital Output Digital Output Digital I/O Digital I/O Digital Input Digital Input Digital Input Digital I/O Digital Input Supply Supply Analog Input Analog Input Functionality MICP Input 2 / Line In Input 2 MICN Input 2 Decoupling for Mid-rail Reference Voltage Decoupling for MIC Reference Voltage Digital Core Supply Digital Ground Digital Buffer (Input/Output) Supply Output from PLL Digital Audio ADC Data Output for ADC 1 and 2 Digital Audio Bit Clock Digital Audio Frame Sync Master Clock Input 3-Wire MPU Chip Select/I2C address LSB 3-Wire MPU Clock Input/I2C Clock (SCL) 3-Wire MPU Data Input/I2C Data I/O (SDA) Control Interface Mode Selection Pin (I2C=1, SPI=0) Analog Power Supply Analog Ground MICN Input 1 MICP Input 1 / Line In Input 1 Analog Output Supply Analog Output Microphone Bias for Microphone ADC 1 Microphone Supply Microphone Bias for Microphone ADC 2 Nuvoton Technology Corporation America Tel: 1-408-544-1718 Fax: 1-408-544-1787 Rev. 0.1.9: May 10, 2016 5 5 Page NAU85L20 The polarity of either ADC output signal can be changed independently on either ADC logic output which can be sometimes useful in management of the audio phase. This feature can help minimize any audio processing that may be otherwise required as the data are passed to other stages in the system. The ADC coding scheme is in twos complement format and the full-scale input level is proportional to VDDA. For example, with a 1.8V supply voltage, the full-scale level is 1.0VRMS. 2.2.1 Input Limiter / Automatic Level Control (ALC) The ADC digital path of the NAU85L20 is supported by the digital Automatic Level Control (ALC) function. This can be used to automatically manage the gain to optimize the signal level at the output of the ADC by automatically amplifying input signals that are too small or decreasing the amplitude of the signals that are too loud. The ALC monitors the output of the ADC, measured after the digital decimator. The ADC output is fed into a peak detector, which updates the measured peak value whenever the absolute value of the input signal is higher than the current measured peak. The measured peak gradually decays to zero unless a new peak is detected, allowing for an accurate measurement of the signal envelope. The peak value is then used by a logic algorithm to determine whether the gain should be increased, decreased, or remain the same. In normal mode, when sudden peaks occur above the desired gain settings, the ALC reduces volume at a register determined rate and step size. This continues until the output level of the ADC is again at the desired target level. If the input signal suddenly becomes quiet, the ALC increases volume at a register determined rate and step size until the output level from the ADC reaches the target level. If the input gain stays within the target level, the ALC will remain in a steady state. In addition to the normal operation mode, the ALC may be operated in a special limiter mode that functions similarly to the normal mode but with faster attack times. This mode is primarily used to quickly ramp down signals that are too loud. 2.2.1.1 ALC Peak Limiter Function Both normal and limiter mode include a peak limiter function. This implements an emergency gain reduction when the ADC output level exceeds a set gain value. When the ADC output exceeds 87.5% of full scale, the ALC block ramps down the gain at the maximum ALC Attack Time rate. This is regardless of the mode and attack rate settings. This continues until the ADC output level has been reduced to below the emergency limit threshold. This action limits ADC clipping if there is a sudden increase in the input signal level. 2.2.1.2 ALC Parameter Definitions ALC Maximum Gain (ALCMAX): This sets the maximum allowed gain during normal mode ALC operation. In the Limiter mode of ALC operation, the ALCMXGAIN value is not used, instead, the maximum gain allowed is set equal to the pre-existing gain value that was in effect at the moment in time that the Limiter mode is enabled. See ALC_CONTROL_2 REG0X21 for details. ALC Minimum Gain (ALCMIN): This sets the minimum allowed gain during all modes of ALC operation. This is useful to keep the ALC operating range close to the desired range for a given application scenario. See ALC_CONTROL_2 REG0X21 for details. ALC Target Value (ALCLVL): Determines the value used by the ALC logic decisions comparing this fixed value with the output of the ADC. This value is expressed as a fraction of Full Scale (FS) output from the ADC. Depending on the logic conditions, either the output value used in the comparison may be the instantaneous value of the ADC, or a time weighted average of the ADC peak output level. See ALC_CONTROL_2 REG0X21 for details. ALC Attack Time (ALCATK): Attack time refers to how quickly a system responds to an increasing volume level that is greater than some defined threshold. Typically, attack time is much faster than decay time. In the NAU85L20, when the absolute value of the ADC output exceeds the ALC Target Value, the gain Nuvoton Technology Corporation America Tel: 1-408-544-1718 Fax: 1-408-544-1787 Rev. 0.1.9: May 10, 2016 11 11 Page

Páginas	Total 30 Páginas
PDF Descargar	[ Datasheet NAU85L20.PDF ]

Hoja de datos destacado

Número de pieza	Descripción	Fabricantes
NAU85L20	Dual Audio ADC	nuvoton

Número de pieza	Descripción	Fabricantes
SLA6805M	High Voltage 3 phase Motor Driver IC.	Sanken
SDC1742	12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters.	Analog Devices

DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares,
permitiéndote verlos en linea o descargarlos en PDF.

DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar