AD1940(SigmaDSP Multichannel,28-Bit Audio Processor)IntroductionThe AD1940/AD1941 are a complete 28- bit, single-chip, multi-channel audio SigmaDSP™ for equalization, multiband dynamic processing,delay compensation, speaker compensation, and image enhancement. These algorithms can compensate for the real-world limitations of speakers, amplifiers, and listening environments, thereby dramatically improving perceived audio quality.The signal processing used in the AD1940/AD1941 is comparable to that found in high end studio equipment. Most of the processing is done in full, 56-bit double-precision mode,resulting in very good, low level signal performance and the absence of limit cycles or idle tones. The dynamics processor uses a sophisticated, multiple-breakpoint algorithm often found in high end broadcast compressors.The AD1940/AD1941 are a fully programmable DSP. Easy to use software allows the user to graphically configure a custom signal processing flow using blocks such as biquad filters, dynamics processors, and surround sound processors. An extensive control port allows click-free parameter updates, along with readback capability from any point in the algorithm flow.The AD1940/AD1941’s digital ports enable direct connection to ADCs and DACs via multiple 2-channel or TDM data streams. In TDM mode, they can handle 8 or 16 channels of serial data both for input and output. The input and output port configurations can be individually set. The AD1940 is controlled by a 4-wire SPI® port, while the AD1941 is controlled by a 2-wire I²C® bus. Other than the control interface, the functions of the two parts are identical.Feature16-channel digital audio processorAccepts sample rates up to 192 kHz28-bit X 28-bit multiplier with full 56-bit accumulatorFully programmable program RAM for custom program downloadParameter RAM allows complete control of 1,024 parametersControl port features safeload for transparent parameter updates and complete mode and memory transfer controlTarget/slew RAM for click-free volume control and dynamic parameter updatesDouble precision mode for full 56-bit processingPLL for generating MCLK from 64 x fs, 256 x fs, 384 x fs, or 512 x fs clocksHardware-accelerated DSP core21 kB (6, 144 words) data memory for up to 128 ms of audio delay at fs = 48 kHzFlexible serial data port with I2S-compatible, left-justified,and right-justified serial port modes8- and 16-channel TDM input/output modesOn-chip voltage regulator for compatibility with 3.3V and 5V systemsProgrammable low power modeFast start-up and boot time from power-on or reset48-lead LQFP plastic packageAppearance
