NAU8502
24-bit Stereo Audio ADC with Differential Microphone Inputs
emPowerAudio
1. GENERAL DESCRIPTION
The NAU8502 is a low power, high quality audio input system for portable applications. In addition to precision
24-bit stereo ADCs, this device integrates a broad range of additional functions to simplify implementation of
complete audio systems. The NAU8502 includes low-noise stereo differential high gain microphone inputs with
wide range programmable amplifiers, separate line inputs, and an analog bypass/sidetone line level stereo output.
Advanced on-chip digital signal processing includes a limiter/ALC (Automatic Level Control), 5-band equalizer,
notch filter, and a high-pass filter for speech optimization and wind noise reduction. The digital interface can
operate as either a master or a slave. Additionally, an internal fractional-N PLL is available to accurately generate
any audio sample rate clock for the ADCs derived using any available system clock from 8MHz through 33MHz.
The NAU8502 operates with analog supply voltages from 2.7V to 3.6V, while the digital core can operate as low
as 1.71V to conserve power. Internal control registers enable flexible power conserving modes, shutting down or
reducing power in sub-sections of the chip under software control.
The NAU8502 is specified for operation from -40C to +85C. AEC-Q100 & TS16949 compliant device is
available upon request.
2. FEATURES
24-bit signal processing linear Audio ADC
ADC: 90dB SNR and -80dB THD(A weighted)
Supports any sample rates from 8KHz - 48kHz
Analog I/O
Very wide range programmable input amplifier
Stereo line inputs with gain options and mixing
Stereo differential input microphone amplifiers
Interfaces
2
Standard audio interfaces: PCM and I S
Serial control interfaces with read/write capability)
emPowerAudio
Datasheet Revision 2.5 Page 1 of 92 March, 2014 NAU8502
Additional features
5-band Graphic Equalizer
Automatic level control / limiter
Programmable Notch Filter
High Pass Filter/ Wind Noise Reduction
Applications
Audio Recording Devices
Security Systems
Video and Still Cameras
Enhanced Audio Inputs for SOC products
Audio Input Accessory Products
Gaming Systems
New Features
Passive LINE OUT
On-Chip LDO
On-chip high resolution fractional-N PLL
LDOVIN
LDO
NAU8502YG
P1OUT
LDOOUT
MIC1N
ADC Filter
Stereo
LADC
Volume
MIC1P
Line Input 5-Band
Control
P1IN Input
and Stereo
LLINOUT
Mixer
Microphone Equalizer
P2OUT
High Pass &
RADC
Differential
Notch Filters RLINOUT
Input
MIC2N
MIC2P
P2IN
Serial Control Interface Digital Audio Interface
2
Microphone
I S PCM
2-wire SPI
MICBIAS GPIO PLL
Bias
VMID
emPowerAudio
Datasheet Revision 2.5 Page 2 of 92 March, 2014