Overview
The PCM2705CDB is a single-chip USB stereo audio digital-to-analog converter (DAC) produced by Texas Instruments. It integrates a USB 2.0 compliant full-speed protocol controller and S/PDIF output, making it a versatile component for various audio applications. The device does not require dedicated device drivers and supports bus-powered or self-powered operation. It employs TI's SpAct architecture, which recovers the audio clock from USB packet data, ensuring low clock jitter during playback.
Key Specifications
| Parameter | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Supply Voltage (VBUS) | 4.35 | 5 | 5.25 | V |
| Supply Voltage (VCCP, VCCL, VCCR, VDD) - Self-Powered | 3 | 3.3 | 3.6 | V |
| Operating Temperature | -25 | 85 | °C | |
| Sampling Rates | 32 kHz, 44.1 kHz, 48 kHz | |||
| THD + N (RL > 10 kΩ, Self-Powered) | 0.006% | |||
| THD + N (RL = 32 Ω) | 0.025% | |||
| SNR | 98 dB | |||
| Dynamic Range | 98 dB | |||
| Package Type | 28-Pin SSOP |
Key Features
- On-Chip USB Interface: Fully compliant with USB 2.0 specification and certified by USB-IF.
- No Dedicated Device Driver Needed: Works with no software code but allows modification of USB descriptors.
- Full-Speed Transceivers: Supports USB 1.1 descriptors with USB audio class support.
- Partially Programmable Descriptors: Allows customization of vendor ID/product ID through external ROM or SPI.
- Adaptive Isochronous Transfer: Ensures smooth playback for USB audio applications.
- Bus-Powered or Self-Powered Operation: Flexible power options with typical voltages of 5 V (bus-powered) and 3.3 V (self-powered).
- On-Chip Clock Generator: Single 12-MHz clock source with SpAct architecture for low clock jitter.
- 16-Bit Delta-Sigma Stereo DAC: High-quality audio conversion with analog performance at 5 V and 3.3 V.
- Analog LPF Included: Analog low-pass filter for improved audio quality.
- Multiple Functions: Up to eight Human Interface Device (HID) interfaces, S/PDIF output with SCMS, and external ROM or SPI interface.
Applications
- USB Audio Interface Boxes
- USB Headphones and Speakers
- USB CRT/LCD Monitors with Audio
- Consumer Audio Products with USB Features
- Other USB-Enabled Audio Devices
Q & A
- What is the typical supply voltage for the PCM2705CDB when bus-powered?
The typical supply voltage when bus-powered is 5 V (VBUS).
- What are the supported sampling rates for the PCM2705CDB?
The supported sampling rates are 32 kHz, 44.1 kHz, and 48 kHz.
- Does the PCM2705CDB require a dedicated device driver?
No, it does not require a dedicated device driver.
- What is the typical THD + N for the PCM2705CDB when RL > 10 kΩ and self-powered?
The typical THD + N is 0.006%.
- What is the package type of the PCM2705CDB?
The package type is 28-Pin SSOP.
- What is the operating temperature range for the PCM2705CDB?
The operating temperature range is -25°C to 85°C.
- Does the PCM2705CDB support S/PDIF output?
- Can the USB descriptors of the PCM2705CDB be modified?
- What is the significance of SpAct architecture in the PCM2705CDB?
The SpAct architecture recovers the audio clock from USB packet data, ensuring low clock jitter during playback.
- What are some common applications of the PCM2705CDB?
