192 kHz Stereo Asynchronous a Sample Rate Converter AD1896 FUNCTIONAL BLOCK DIAGRAM FEATURES Automatically Senses Sample Frequencies GRPDLYS RESET VDD IO VDD CORE No Programming Required Attenuates Sample Clock Jitter AD1896 MUTE I 3.3 V5 V Input and 3.3 V Core Supply Voltages Accepts 16-/18-/20-/24-Bit Data FS OUT SDATA I FIFO SDATA O FS Up to 192 kHz Sample Rate SCLK I IN SCLK O LRCLK I LRCLK O Input/Output Sample Ratios from 7.75:1 to 1:8 SERIAL SMODE IN 0 INPUT Bypass Mode TDM IN SMODE IN 1 SERIAL Multiple AD1896 TDM Daisy-Chain Mode SMODE IN 2 OUTPUT FIR SMODE O 0 DIGITAL Multiple AD1896 Matched-Phase Mode FILTER SMODE O 1 PLL BYPASS 142 dB Signal-to-Noise and Dynamic Range MUTE O (A-Weighted, 20 Hz20 kHz BW) WLNGTH O 0 WLNGTH O 1 Up to 133 dB THD + N CLOCK DIVIDER ROM Linear Phase FIR Filter Hardware Controllable Soft Mute MCLK I MSMODE 0 MSMODE 2 Supports 256 f , 512 f , or 768 f Master S S S MCLK O MSMODE 1 Mode Clock Flexible 3-Wire Serial Data Port with Left-Justified, 2 I S, Right-Justified (16-,18-, 20-, 24-Bits), and port supports TDM mode for daisy-chaining multiple AD1896s to TDM Serial Port Modes a digital signal processor. The serial output data is dithered down Master/Slave Input and Output Modes to 20, 18, or 16 bits when 20-, 18-, or 16-bit output data is se- 28-Lead SSOP Plastic Package lected. The AD1896 sample rate converts the data from the serial input port to the sample rate of the serial output port. The APPLICATIONS sample rate at the serial input port can be asynchronous with Home Theater Systems, Studio Digital Mixers, respect to the output sample rate of the output serial port. The Automotive Audio Systems, DVD, Set-Top Boxes, master clock to the AD1896, MCLK, can be asynchronous to Digital Audio Effects Processors, Studio-to-Transmitter both the serial input and output ports. Links, Digital Audio Broadcast Equipment, DigitalTape Varispeed Applications MCLK can be generated either off-chip or on-chip by the AD1896 master clock oscillator. Since MCLK can be asynchronous to the input or output serial ports, a crystal can be used to generate MCLK internally to reduce noise and EMI emissions on the PRODUCT OVERVIEW board. When MCLK is synchronous to either the output or input The AD1896 is a 24-bit, high performance, single-chip, second- serial port, the AD1896 can be configured in a master mode where generation asynchronous sample rate converter. Based on Analog MCLK is divided down and used to generate the left/right Devices experience with its first asynchronous sample rate and bit clocks for the serial port that is synchronous to MCLK. converter, the AD1890, the AD1896 offers improved performance The AD1896 supports master modes of 256 f , 512 f , S S and additional features. This improved performance includes a and 768 f for both input and output serial ports. S THD + N range of 117 dB to 133 dB depending on the sample rate and input frequency, 142 dB (A-Weighted) dynamic range, Conceptually, the AD1896 interpolates the serial input data by 20 192 kHz sampling frequencies for both input and output sample a rate of 2 and samples the interpolated data stream by the 20 rates, improved jitter rejection, and 1:8 upsampling and 7.75:1 output sample rate. In practice, a 64-tap FIR filter with 2 downsampling ratios. Additional features include more serial polyphases, a FIFO, a digital servo loop that measures the time formats, a bypass mode, better interfacing to digital signal pro- difference between the input and output samples within 5 ps, cessors, and a matched-phase mode. and a digital circuit to track the sample rate ratio are used to perform the interpolation and output sampling. Refer to the The AD1896 has a 3-wire interface for the serial input and 2 Theory of Operation section. The digital servo loop and sample output ports that supports left-justified, I S, and right-justified rate ratio circuit automatically track the input and output (16-, 18-, 20-, 24-bit) modes. Additionally, the serial output sample rates. (Continued on Page 17) REV. A Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. may result from its use. No license is granted by implication or otherwise Tel: 781/329-4700 www.analog.com under any patent or patent rights of Analog Devices. Trademarks and Fax: 781/326-8703 2003 Analog Devices, Inc. All rights reserved. registered trademarks are the property of their respective companies.AD1896SPECIFICATIONS TEST CONDITIONS, UNLESS OTHERWISE NOTED. Supply Voltages VDD CORE 3.3 V VDD IO 5.0 V or 3.3 V Ambient Temperature 25C Input Clock 30.0 MHz Input Signal 1.000 kHz, 0 dBFS Measurement Bandwidth 20 to f /2 Hz S OUT Word Width 24 Bits Load Capacitance 50 pF Input Voltage High 2.4 V Input Voltage Low 0.8 V Specifications subject to change without notice. DIGITAL PERFORMANCE (VDD CORE = 3.3 V 5%, VDD IO = 5.0 V 10%) Parameter Min Typ Max Unit Resolution 24 Bits Sample Rate MCLK I = 30 MHz 6 215 kHz 1 Sample Rate ( Other Master Clocks) MCLK I/5000 f < MCLK I/138 kHz S Sample Rate Ratios Upsampling 1:8 Downsampling (Short GRPDLYS) 7.75:1 Downsampling (Long GRPDLYS) 7.0:1 2 Dynamic Range (20 Hz to f /2, 1 kHz, 60 dBFS Input) A-Weighted S OUT Worst-Case (192 kHz:48 kHz) 132 dB 44.1 kHz:48 kHz 142 dB 48 kHz:44.1 kHz 141 dB 48 kHz:96 kHz 142 dB 44.1 kHz:192 kHz 141.5 dB 96 kHz:48 kHz 140 dB 192 kHz:32 kHz 140 dB (20 Hz to f /2, 1 kHz, 60 dBFS Input) No Filter S OUT Worst-Case (192 kHz:48 kHz) 132 dB 44.1 kHz:48 kHz 139 dB 48 kHz:44.1 kHz 139 dB 48 kHz:96 kHz 139 dB 44.1 kHz:192 kHz 137 dB 96 kHz:48 kHz 137 dB 192 kHz:32 kHz 138 dB 2 Total Harmonic Distortion + Noise (20 Hz to f /2, 1 kHz, 0 dBFS Input) No Filter S OUT 3 Worst-Case (32 kHz:48 kHz) 117 dB 44.1 kHz:48 kHz 123 dB 48 kHz:44.1 kHz 124 dB 48 kHz:96 kHz 120 dB 44.1 kHz:192 kHz 123 dB 96 kHz:48 kHz 132 dB 192 kHz:32 kHz 133 dB Interchannel Gain Mismatch 0.0 dB Interchannel Phase Deviation 0.0 Degrees Mute Attenuation (24 Bits Word Width) (A-Weighted) 144 dB NOTES 1 Lower sampling rates than given by this formula are possible, but the jitter rejection will decrease. 2 Refer to the Typical Performance Characteristics section for DNR and THD + N numbers over wide range of input and output sample rates. 3 For any other sample rate ratio, the minimum THD + N will be better than 117 dB. Please refer to detailed performance plots. Specifications subject to change without notice. 2 REV. A