Texas Instruments PCM2900E/2K

Overview

PCM2900E/2K from Texas Instruments is a single-chip stereo audio codec with integrated USB 1.1 full-speed interface, 16-bit delta-sigma ADC and DAC, single-ended analog I/O, and no S/PDIF support. It operates from a single 5-V bus supply, supports adaptive playback and asynchronous recording, and delivers 89 dB SNR (ADC) and 96 dB SNR (DAC) at 44.1 kHz - used in USB audio speaker and headset designs.

For engineers reviewing the PCM2900E/2K datasheet, PCM2900E/2K pinout, PCM2900E/2K application, or PCM2900E/2K equivalent, key selection considerations include its SSOP-28 package, SpAct™ clock recovery architecture, HID volume/mute control capability, suspend flag output, and absence of S/PDIF functionality compared to PCM2902E/2K.

Technical Context

The PCM2900E/2K implements TI's SpAct™ architecture to recover audio clocks directly from USB packet timing, enabling low-jitter playback and independent ADC/DAC sampling rates without external crystal oscillators beyond the required 12-MHz input. Its USB protocol controller operates autonomously with no firmware required.

It integrates analog antialiasing and reconstruction filters, on-chip decimation/interpolation digital filters, and a 5-V-to-3.3-V internal regulator. The device uses four USB interfaces: control (IF #0), isochronous-out streaming (IF #1), isochronous-in streaming (IF #2), and HID (IF #3), supporting standard USB audio class descriptors.

Key Specifications

Pinout & Package

PCM2900E/2K is housed in a 28-pin SSOP (28DB) package with 0.65-mm lead pitch and exposed pad not present. Pin functions are electrically validated per TI SLES035E datasheet Rev. March 2008.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar stereo USB audio codec applications.

Compared with PCM2902E/2K, PCM2900E/2K removes S/PDIF circuitry to reduce cost and power (67 mA vs. 72 mA typical), while retaining identical USB audio class compliance and analog performance; versus CY7C68013A-56PVXC, it eliminates firmware development, external codec BOM, and clock tree design effort.

Availability

PCM2900E/2K is available at Aetrix Electronics and suitable for USB audio speaker, USB headset, and USB monitor audio applications requiring stable component supply and long-term industrial availability.

Supply support for PCM2900E/2K includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and connectivity technologies with over 50 years of innovation in signal chain and power management ICs.

The PCM2900 product line was designed specifically for cost-sensitive, plug-and-play USB audio peripherals - delivering fully integrated, driverless stereo audio conversion with minimal external components and zero firmware overhead.

FAQ

What is the maximum sampling rate supported by the PCM2900E/2K DAC?

The PCM2900E/2K DAC supports playback sampling rates of 32 kHz, 44.1 kHz, and 48 kHz only. It does not support 8, 11.025, 16, or 22.05 kHz on the DAC side - those rates are ADC-only. This limitation is inherent to the DAC interpolation filter design and is documented in the Electrical Characteristics table of the PCM2900E/2K datasheet.

Does the PCM2900E/2K require an external crystal oscillator?

Yes, the PCM2900E/2K requires a 12-MHz fundamental-mode crystal connected between XTI (pin 21) and XTO (pin 20). The internal PLL uses this reference to generate the precise clocks needed for USB packet timing and audio sampling. No external clock source or oscillator module is supported - only a parallel-resonant crystal with load capacitance matching the datasheet recommendation (12 pF typical).

Can the PCM2900E/2K operate from a 3.3-V supply instead of 5 V?

No, the PCM2900E/2K is strictly 5-V bus-powered and requires VBUS between 4.35 V and 5.25 V. Its internal 3.3-V regulators (VCCCI, VCCP1I, etc.) are derived from VBUS and cannot be bypassed or back-powered. Applying 3.3 V to VBUS will prevent operation and may damage the device per Absolute Maximum Ratings.

Is the PCM2900E/2K pin-compatible with the PCM2902E/2K?

Yes, the PCM2900E/2K and PCM2902E/2K share identical 28-pin SSOP packaging, pinout, and power sequencing. The only functional difference is that PCM2902E/2K adds DIN (pin 24) and DOUT (pin 25) for S/PDIF, which are NC (no-connect) on PCM2900E/2K. All other pins - including USB, analog I/O, HID, and power - are functionally and electrically identical.

What USB audio class descriptors does the PCM2900E/2K implement?

The PCM2900E/2K implements standard USB Audio Class 1.0 descriptors across four interfaces: IF #0 (audio control), IF #1 (isochronous-out streaming), IF #2 (isochronous-in streaming), and IF #3 (HID). It supports volume/mute feature units, terminal types for speaker/microphone/USB stream, and is certified by USB-IF - enabling native OS driver support on Windows, macOS, and Linux without custom INF files.