Cx31993 Datasheet Fix Better Access
The CX31993 is a popular high-fidelity USB-C audio codec known for delivering 32-bit/384kHz audio in a compact, low-power form factor. While its official datasheet lists impressive specs like a >128dB signal-to-noise ratio (SNR), users often encounter real-world implementation issues such as static hiss, overheating, and connectivity drops. Key Technical Specifications Specification DAC Resolution 32-bit / 384kHz SNR / DNR >128dB / >120dB Distortion (THD+N) 0.0003% (-95dB) Output Power ~65mW @ 32Ω Compatibility USB Audio Class (UAC) 1.0/2.0 (Plug-and-play) Common Implementation Issues & Fixes 1. Static Hiss and Noise Floor
Users frequently report a buzzing or "hissing" sound, especially with sensitive In-Ear Monitors (IEMs). Conexant (CX-Pro) CX31993 USB-C Amp/DAC Review cx31993 datasheet fix better
Quick Reference: Best Practice Schematic Fixes
| Original issue | Corrected implementation | |----------------|--------------------------| | 1µF + 0.1µF decoupling | + add 1nF high-freq cap | | No I²C pull-ups | 2.2kΩ to 3.3V on SDA/SCL | | 32.768 kHz crystal | 12.5pF load + 15pF caps | | No output filter | 3rd-order LPF (22Ω/470pF/10Ω/1nF) | | Direct VBUS power | 5V → 3.3V LDO (e.g., TPS73633) | The CX31993 is a popular high-fidelity USB-C audio
3. Sample Rate Switching Without Pops
The official (leaked) partial datasheet suggests register 0x06 controls muting during rate switching.
Better Setting: Configure your OS to use the same sample rate across all apps. Quick Reference: Best Practice Schematic Fixes | Original
- Windows: Set default format to 24-bit/192kHz.
- Linux: Create a PipeWire rule to lock the CX31993 to 32-bit/176.4kHz (the chip’s cleanest clock domain).
Step 4: Include Application Notes and Examples
Application notes and examples can help users understand how to use the component in different applications. Consider including:
- Example circuits: Provide example circuits to demonstrate how to use the component in different applications.
- Application notes: Provide application notes to help users optimize the component's performance in specific applications.