PCM2705C - 98dB SNR Stereo USB DAC with S/PDIF | Texas Instruments
MPN: PCM2705C ✓ Hoạt độngPCM2705C Tóm tắt
A USB audio DAC is a digital-to-analog converter that receives digital audio data from a USB host and converts it to analog audio signals. It integrates the USB interface, protocol controller, and DAC core into a single chip, simplifying system design. The PCM2705C sits in the hierarchy of audio converters, specifically as a USB audio interface IC, which is a subset of audio data converters within the broader category of mixed-signal ICs.
Key features include a 98dB SNR stereo DAC, S/PDIF output, and support for both bus-powered and self-powered modes. The device also features partially programmable USB descriptors, allowing customization of vendor ID and product ID via an external SPI host. The integrated USB transceiver eliminates the need for external PHY, reducing BOM cost and board space.
Technically, the PCM2705C uses adaptive isochronous transfer for audio data, ensuring synchronized playback. The S/PDIF output supports digital audio transmission to external decoders or amplifiers. The device operates from a 3.3V supply and includes an internal PLL for clock generation, minimizing external components. The SSOP-28 package provides a compact footprint suitable for portable and space-constrained designs.
Typical applications include USB sound cards, docking stations, gaming headsets, and portable audio interfaces. The device's plug-and-play capability makes it ideal for consumer audio products where driver installation is undesirable. Its low power consumption and small size also suit battery-powered devices.
When designing with the PCM2705C, ensure proper decoupling of the 3.3V supply and careful layout of the USB differential pair to maintain signal integrity. The SPI interface for descriptor programming should be configured during initial setup, and the PSEL and HOST pins must be set correctly for the desired operating mode.
Bộ thay thế dễ dàng lắp đặt cho PCM2705C — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
PCM2705
📋 Tham chiếu thay thế (không có trong danh mục)
PCM2704C
📋 Tham chiếu thay thế (không có trong danh mục)
PCM2706C
📋 Tham chiếu thay thế (không có trong danh mục)
PCM2707C
📋 Tham chiếu thay thế (không có trong danh mục)
PCM2902
📋 Tham chiếu thay thế (không có trong danh mục)
PCM2705C Tỷ lệ tối đa & tính chất điện
| SNR (DAC) | 98 dB |
| USB Interface | USB 2.0 Full-Speed |
| USB Compliance | USB 2.0, USB Audio Class |
| Kiểu đầu ra | Line-out, S/PDIF |
| Power Supply | 3.3 V |
| Power Mode | Bus-powered or Self-powered |
| Control Interface | SPI (for descriptor programming) |
| Hộp | SSOP-28 |
| Nhiệt độ hoạt động | -25C to +85C |
| Kiểu lắp đặt | Surface Mount |
| Trạng thái RoHS | Compliant |
| Number of Channels | 2 (Stereo) |
Cấu hình chân PCM2705C
| Chân 1 | VCC — Power supply (3.3V) |
| Chân 2 | GND — Ground |
| Chân 3 | D+ — USB data plus |
| Chân 4 | D- — USB data minus |
| Chân 5 | VOUTL — Left analog output |
| Chân 6 | VOUTR — Right analog output |
| Chân 7 | S/PDIF — S/PDIF digital output |
| Chân 8 | SPI_CLK — SPI clock |
| Chân 9 | SPI_CS — SPI chip select |
| Chân 10 | SPI_DIN — SPI data in |
| Chân 11 | SPI_DOUT — SPI data out |
| Chân 12 | PSEL — Power select |
| Chân 13 | HOST — Host select |
| Chân 14 | XTAL_IN — Crystal oscillator input |
| Chân 15 | XTAL_OUT — Crystal oscillator output |
Ứng dụng tiêu biểu
PCM2705C phù hợp cho 6 Áp dụngs: USB Sound Cards, Docking Stations, Gaming Headsets, Portable Audio Interfaces, Consumer Audio Electronics, Automotive Infotainment.
USB Sound Cards
The PCM2705C is ideal for USB sound cards, providing plug-and-play audio without dedicated drivers. Its 98dB SNR ensures high-fidelity audio output, while the integrated USB controller simplifies design. The S/PDIF output allows digital audio transmission to external DACs or amplifiers, making it versatile for various audio systems.
Được đề xuất
Docking Stations
In docking stations, the PCM2705C provides USB audio connectivity for laptops and tablets. Its bus-powered mode eliminates the need for external power, simplifying design. The S/PDIF output can route digital audio to home theater systems, while the stereo DAC drives analog outputs for speakers or headphones. The compact SSOP-28 package fits space-constrained docking designs.
Được đề xuất
Gaming Headsets
The PCM2705C is well-suited for gaming headsets, offering high SNR for immersive audio. Its USB interface ensures compatibility with PCs and consoles without driver installation. The device supports both bus-powered and self-powered modes, allowing flexible power design. The S/PDIF output can be used for virtual surround sound processing, enhancing the gaming experience.
Được đề xuất
Portable Audio Interfaces
For portable audio interfaces, the PCM2705C offers low power consumption and a small footprint. Its USB bus-powered mode allows operation directly from a laptop or mobile device. The 98dB SNR ensures high-quality audio recording and playback. The SPI interface enables descriptor customization for branding, making it suitable for OEM products.
Được đề xuất
Consumer Audio Electronics
The PCM2705C is used in consumer audio devices like sound bars and AV receivers. Its S/PDIF output allows digital audio routing to external decoders, while the stereo DAC provides analog outputs. The device's USB compliance ensures easy connectivity with TVs and media players. The compact package and low power consumption make it ideal for consumer electronics.
Được đề xuất
Automotive Infotainment
In automotive infotainment systems, the PCM2705C provides USB audio playback from smartphones and media players. Its robust USB interface ensures reliable operation in automotive environments. The S/PDIF output can interface with external audio processors, while the stereo DAC drives analog audio signals. The device's small package is suitable for head units and rear-seat entertainment systems.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho PCM2705C — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | PCM2705 | PCM2704C | PCM2706C | PCM2707C |
|---|---|---|---|---|---|
| Package | SSOP-28 | SSOP-28 | SSOP-28 | SSOP-28 | SSOP-28 |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| SNR | 98 dB | 98 dB | 98 dB | 98 dB | 98 dB |
| USB Interface | USB 2.0 Full-Speed | USB 2.0 Full-Speed | USB 2.0 Full-Speed | USB 2.0 Full-Speed | USB 2.0 Full-Speed |
| Descriptor Programming | SPI | Fixed | External ROM | External ROM | SPI |
| S/PDIF Output | Yes | Yes | Yes | Yes | Yes |
| Power Mode | Bus/Self-powered | Bus/Self-powered | Bus/Self-powered | Bus/Self-powered | Bus/Self-powered |
| Operating Temperature | -25C to +85C | -25C to +85C | -25C to +85C | -25C to +85C | -25C to +85C |
Bảo phân biệt quan trọng
- SPI-based descriptor programming (vsPCM2704C)
- 98dB SNR (vsPCM2902)
- Integrated S/PDIF output (vsPCM2705)
Ghi chú thiết kế
The PCM2705C operates from a 3.3V supply. Use a low-noise LDO, such as the TPS7A4700, to power the analog section and minimize noise. Decouple the VCC pin with a 10uF ceramic capacitor and a 0.1uF capacitor close to the pin. Ensure the ground plane is solid to reduce noise coupling.
For USB signal integrity, route the D+ and D- traces as a differential pair with controlled impedance (90 ohms). Keep the traces short and avoid vias. Place the crystal oscillator close to the XTAL_IN and XTAL_OUT pins, and ensure proper grounding around it to prevent EMI.
When using the SPI interface for descriptor programming, ensure the PSEL and HOST pins are configured correctly. Incorrect settings may cause the device to enter an unintended mode. Also, verify that the external ROM or SPI host is properly initialized before the device enumerates on the USB bus.
Thông tin tuân thủ
RoHS compliant per TI product page. Other compliance data not specified in provided sources.
