audio/videoZONE Products for the week of July 21, 2003
Texas Instruments Says . . .
SRC4190/2/3: High Performance Sample Rate Converters
For Professional Audio
Devices Achieve 144-dB Dynamic Range, -140-dB THD+N
Texas Instruments (TI) Incorporated introduced the industry's highest performance sample rate converters from the company's Burr-Brown Pro Audio product line. Featuring 144dB dynamic range and -140dB distortion, the devices are ideal for a variety of professional audio applications, such as digital mixing consoles, digital audio workstations, audio distribution, high-end A/V receivers and broadcast studio equipment.
The SRC4192/3 combines a wide input-to-output sampling ratio (handling all major audio rates up to 212kHz) with outstanding dynamic range (144dB) and ultra-low distortion (-140dB THD+N). Input and output serial ports support standard audio formats. The flexible audio interfaces allow the SRC4192/3 to connect to a wide range of audio data converters, digital audio receivers/transmitters and digital signal processors.
The SRC4192 is a standalone pin-programmed device, with control pins
for mode, data format, mute, bypass and low group delay functions. The SRC4193
is a software-controlled device featuring a serial peripheral interface
(SPI), which is utilized to program all functions via internal control registers.
A lower-cost, pin-compatible device, the SRC4190, is also available with
128dB dynamic range and -125dB THD+N.
analogZONE Says...
Wow! Numbers such as 144 dB dynamic range, -140 dB distortion are just phenomenal, major jumps from previous sample rate converters. TI has also made the jump from 96 kHz up to a top end of 212 kHz sampling for both input and output rates with input/output sampling ratio range of 16:1 and 1:16. One has to wonder how much the top-end audio market OEMs are going to charge for a box with one of these ICs at its core!
The rail is from 3.0 V to 3.6 V with the digital interfaces from 1.65 V to 3.6 V. The total dynamic power dissipation is a typical 225 mW with shutdown for the SRC1493 at a typical 16.6 mW and 0.66 mW for the SRC1492, an advantage of hardware control. The SPI interface on the SRC1493 can operate up to 25 MHz.
All the FFT plots under various converter conditions are absolutely clean, while the THD+N plots show almost perfect flatness across complete input ranges, and the linearity is also well nigh perfect. The low group delay numbers are also very impressive.
In the IC, the audio data input is clocked by either the data in slave mode or by the IC in a master mode; a similar arrangement is used at the output so the product is fully asynchronous. Interpolation filters up-sample the input data and they are then passed to the re-sampler, decimation filters (or a direct down sampler in the SRC4193) to a mux and the output port.
These parts will clean up in any application over 96 kHz -- there is nothing else that I know of -- and will be snatched up by the professional audio industry.
The SRC4190, SRC4192, and SRC4193 are in production in SSOP-28 and are priced at $5.95 for the SRC4190, and $9.95 for both the SRC4192 and SRC4193, all for 1000-piece lots. Evaluation modules are also available.