Cx31993 Datasheet Fix [ Plus | 2026 ]
| Original Datasheet Claim | Corrected Information (Fix v2.1) | Impact | |--------------------------|----------------------------------|---------| | I²C slave address 0x22 | 0x20 (7-bit) | Without this, register writes silently fail. | | Pin 11 = “RESERVED” | GPIO1 (active-low headphone detect) | Enables auto switch between speaker and headphone. | | Max HP output = 1.0Vrms | 1.24Vrms (into 32Ω) | Explains why some dongles measure higher THD at “max volume.” | | Missing register 0x0F | DAC de-emphasis control | Critical for 44.1 kHz linearity. |
The document also includes a verified register dump from a working Tenhz T4 dongle, serving as a golden reference.
The Windows USB Audio driver defaults to a very small buffer. A registry fix increases stability.
Warning: Backup your registry first.
If you use music production software (Ableton, FL Studio) and experience dropouts, install a third-party ASIO wrapper:
The CX31993’s native driver (Microsoft’s inbox driver) has poor low-latency performance; ASIO4ALL acts as a buffer manager.
If you need actual register values, I²C commands, or a reference schematic for a verified working CX31993 implementation, provide the exact markings from the chip (photo or text) – many variants exist under the same “CX31993” name.
Finding a comprehensive official datasheet for the Synaptics (formerly Conexant) CX31993 can be difficult as the manufacturer often restricts these documents to registered partners. Cx31993 Datasheet Fix
If you are "making a paper" (such as a technical report, review, or DIY guide), you can synthesize the technical specifications and community findings currently available. CX31993 Unofficial Technical Specification
Based on user testing and verified hardware implementations, here are the key parameters:
Chipset Architecture: Integrated USB Audio Class 2.0 SOC with a built-in DAC and Class G headphone amplifier.
Resolution & Sampling: Supports up to 32-bit / 384kHz PCM audio. Signal-to-Noise Ratio (SNR): Typically rated around 128dB. Dynamic Range (DNR): ~120dB. Total Harmonic Distortion (THD+N): Rated at -95dB.
Power Output: Approximately 65mW into 32Ω (typical for most dongle implementations). Input Interface: USB Type-C.
Output Support: 3.5mm Single-Ended (supports inline microphones and remote controls). Community-Reported Performance "Fixes"
If your paper focuses on addressing common issues with this chip, consider these documented observations: | Original Datasheet Claim | Corrected Information (Fix v2
Filtering Ultrasonic Noise: Users have reported significant electrical noise above 200kHz (Class G switching/Class D artifacts). Adding a simple Low-Pass Filter (LPF) to the output can help clean the signal for sensitive gear like oscilloscopes or high-end IEMs.
OS Compatibility: For those using FreeBSD or other Linux-based systems, setting hw.snd.default_auto=2 can resolve auto-configuration issues when plugging and unplugging the device.
Physical Durability: The most frequent "fail point" is the thin C-to-C cable. For a DIY project or product, replacing this with a high-purity copper or silver-plated cable is a recommended modification to prevent core breakage.
Signal Comparisons: Reviewers from Reddit and Facebook note that while the CX31993 is a budget powerhouse, it may have a higher noise floor (static at low volumes) compared to higher-tier chips like the Cirrus Logic CS43131. Audio Expansion Card - CX31993 Datasheet
(often branded as Conexant or CX-Pro) is a popular high-performance USB-C DAC/Amp chip widely used in budget "dongle" adapters. While it is praised for its high signal-to-noise ratio and clean output, it is notorious for having a "private" or difficult-to-locate official datasheet, which has led community developers to document their own "fixes" and findings. Framework Community Core Specifications Overview
The chip is a highly integrated Class G audio codec. Its standard operating parameters include: Framework Community Sampling Rate: Up to 32-bit / 384kHz. Signal-to-Noise Ratio (SNR): Dynamic Range (DNR): 0.0003% (-95dB). Output Power: Typically 65mW @ 32Ω. Common Issues & "Datasheet Fixes"
Because the official datasheet is often unavailable to individual developers, users and engineers have identified several hardware and software issues requiring specific workarounds: 1. High-Frequency Noise Leakage If you need actual register values, I²C commands,
Community tests have revealed electrical noise above 200kHz. Framework Community
Implementation of a low-pass filter (LPF) on the output stage is recommended to remove supersonic noise that may interfere with sensitive equipment like oscilloscopes or high-sensitivity IEMs. Framework Community 2. Bit-Depth Detection Errors (Windows 11)
On some systems, particularly Windows 11, the CX31993 may be incorrectly detected as a 16-bit device rather than 32-bit. Any link to the cx31993 datasheet?
The CX31993 is a low-power, high-performance audio codec from Conexant (now part of Synaptics). It’s famous for powering affordable USB-C dongles (like the Ablet, Ugreen, or JCALLY JM6) that support 32-bit/384kHz audio and a 114dB signal-to-noise ratio.
After all software fixes, some CX31993 dongles are simply defective due to:
If you experience persistent hiss with low-impedance IEMs or connection drops when moving the cable, no registry tweak will help. Return the dongle and buy one from a reputable manufacturer that publishes its own application notes (the consumer-friendly version of a datasheet).
Brands with reliable CX31993 implementations:
If you are maintaining an internal datasheet for CX31993, append this errata:
Errata CX31993 Rev A