Datasheet

1 Products

2 Problems, Restrictions, Workaround

2.1 1-kHz Noise During Recording

Errata

SLAZ036A – April 2007 – Revised May 2008

PCM290x Errata

Certain conditions may cause problems for the USB Audio CODEC products.

USB Audio CODEC, PCM290X family

PCM2900, PCM2901, PCM2902, PCM2903, PCM2904, PCM2906

Problems

When using the Alternative setting condition (“0A”, “0B”, “0”C”, “0D”, “0E”) for streaming data-in during

recording, the data from the ADC is NOT transferred to the USB/PC correctly. This may result in 1-kHz

noise on the transferred audio data.

There is a 5% probability that the condition will appear at the start of a recording; however, it depends

on the sampling conditions.

Restrictions

The problem occurs with the following conditions:

• “0A” : 16 kHz, 16 bits, Mono

• “0B” : 16 kHz, 8 bits, Stereo

• “0C” : 16 kHz, 8 bits, Mono

• “0D” : 8 kHz, 8 bits, Stereo

• “0E“ : 8 kHz, 8 bits, Mono

However, in application software using a standard API and working on a standard Windows™ system,

an 8-bit data request from the application software is automatically changed to a sampling condition of

48 kHz, 16 bits, stereo. This process prevents the “8-bit request data” from creating the problem.

So, the setting of ”0B” to “0E” as listed above is NOT a problem in an actual Windows™ environment.

Only the ”0A” (16 kHz, 16 bits, Mono mode) setting creates the noise problem.

Workaround

Since it is not possible to solve this problem by any modification of external circuit, the user must apply

the setting other than ”0A” to avoid the problem in application software.

TI is considering corrections to solve the problem, and will notify the user when a solution is

determined.

Windows is a trademark of Microsoft.

All other trademarks are the property of their respective owners.

SLAZ036A – April 2007 – Revised May 2008 PCM290x Errata 1

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Errata SLAZ036A – April 2007 – Revised May 2008 PCM290x Errata Certain conditions may cause problems for the USB Audio CODEC products. 1 Products USB Audio CODEC, PCM290X family PCM2900, PCM2901, PCM2902, PCM2903, PCM2904, PCM2906 2 Problems, Restrictions, Workaround 2.1 1-kHz Noise During Recording Problems When using the Alternative setting condition (“0A”, “0B”, “0”C”, “0D”, “0E”) for streaming data-in during recording, the data from the ADC is NOT transferred to the USB/PC correctly.
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Problems, Restrictions, Workaround 2.2 www.ti.com Inter-Channel Phase Difference Problems The PCM290X has delay of 1 sample at each channels as follows: • Up-stream data from ADC, S/PDIF in : Rch data delay (1 sample) • Down-stream data to DAC, S/PDIF out : Lch data delay (1 sample) Restrictions Recording or playback of general audio or S/PDIF In/Out of Linear PCM, makes minimal difference to the listener.
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IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete.