Texas Instruments PCM2900E

Overview

PCM2900E from Texas Instruments is a single-chip USB 1.1-compliant stereo audio codec with integrated full-speed USB transceiver, 16-bit delta-sigma ADC and DAC, single-ended analog I/O, and on-chip clock generator using a 12-MHz crystal. It supports adaptive playback (USB isochronous OUT) and asynchronous record (USB isochronous IN), operates from a single 5-V bus supply, and delivers THD+N of 0.01% (ADC) and 0.005% (DAC) at 44.1 kHz.

For engineers reviewing the PCM2900E datasheet, PCM2900E pinout, PCM2900E application, or PCM2900E equivalent, this page provides verified technical context for USB audio interface design, including SpAct™ clock recovery architecture, HID volume/mute control implementation, analog front-end grounding scheme, and SSOP-28 package layout considerations.

Technical Context

The PCM2900E 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 PLLs. Its USB protocol controller requires no firmware - only configurable descriptors - and supports four USB interfaces: standard audio control (IF #0), stereo isochronous OUT (IF #1), stereo isochronous IN (IF #2), and HID (IF #3).

It integrates dual analog PLLs for ADC and DAC paths, on-chip decimation/interpolation digital filters with ±0.05 dB pass-band ripple (ADC) and ±0.1 dB (DAC), antialiasing and LPF analog filters, and a 5-V-to-3.3-V internal regulator. The device uses separate analog ground domains (AGNDC, AGNDP, AGNDX) and digital grounds (DGND, DGNDU) to isolate noise-sensitive signal paths.

Key Specifications

Pinout & Package

PCM2900E is housed in a 28-pin SSOP (Shrink Small Outline Package) with 0.65-mm lead pitch, JEDEC MO-153 compliant, and marked "PCM2900E". Thermal resistance θ_JA = 100°C/W.

Key Features

Applications

Equivalent & Alternatives

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

Compared with PCM2902E, PCM2900E removes S/PDIF circuitry to reduce analog noise coupling and simplify layout; compared with CY7C65632, PCM2900E delivers higher-fidelity audio (96 dB DAC SNR vs. unspecified hub-audio SNR) and eliminates dependency on external converters.

Availability

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

Supply support for PCM2900E 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 company specializing in analog, embedded processing, and connectivity technologies with leadership in precision signal chain and power management solutions.

The PCM2900E belongs to TI's Burr-Brown audio codec product line, designed specifically for cost-sensitive, bus-powered USB audio peripherals requiring high-fidelity analog performance and zero-host-firmware operation.

FAQ

What is the maximum supported sampling rate for ADC and DAC in PCM2900E?

The PCM2900E supports ADC sampling rates of 8, 11.025, 16, 22.05, 32, 44.1, and 48 kHz, and DAC sampling rates of 32, 44.1, and 48 kHz. These rates are implemented via USB isochronous transfer modes - ADC uses asynchronous mode, DAC uses adaptive mode - both managed internally by the SpAct™ engine without host-side clock synchronization.

Does PCM2900E require an external crystal oscillator?

Yes, PCM2900E requires an external 12-MHz fundamental-mode crystal connected to XTI/XTO pins. The device does not include an internal oscillator; the crystal provides the base clock for on-chip PLLs that generate ADC/DAC sampling clocks and USB timing. Load capacitance must be 22 pF per terminal, and frequency tolerance should be ±100 ppm.

How does the HID interface function in PCM2900E?

The PCM2900E implements a dedicated HID interface (Interface #3) that reports mute, volume up, and volume down button states via pins HID0, HID1, and HID2. These are 3.3-V CMOS inputs with internal pulldowns - pressing a switch pulls the pin high. The USB host interprets these as standard HID usage codes; no audio data path involvement occurs.

Can PCM2900E operate from a 3.3-V supply instead of 5 V?

No, PCM2900E is designed for 5-V bus-powered operation only. Its absolute maximum VBUS rating is 6.5 V, and minimum operating voltage is 4.35 V. The internal 3.3-V regulators (VCCCI, VCCP1I, etc.) derive from VBUS - no external 3.3-V rail is accepted. Attempting 3.3-V operation will prevent startup and damage is possible.

What is the purpose of the separate analog ground pins (AGNDC, AGNDP, AGNDX) on PCM2900E?

AGNDC, AGNDP, and AGNDX provide isolated return paths for the codec core, PLL, and crystal oscillator circuits respectively. This separation prevents noise coupling - e.g., PLL switching noise from modulating ADC reference or oscillator jitter from degrading DAC performance. They must be connected to a common analog ground plane at a single point near the device, not daisy-chained.