Cx31993 Datasheet Fix Better May 2026

Conexant CX31993 is a high-performance USB Type-C digital-to-analog converter (DAC) chip widely used in ultra-portable "dongle" DACs to upgrade mobile audio. It is known for delivering clean, transparent sound with a significant improvement in resolution over standard phone outputs. Amazon.com Key Specifications Specification Sampling Rate Up to 384kHz / 32-bit PCM Signal-to-Noise Ratio (SNR) 95dB to 128dB (depending on implementation) 0.0007% ~ 0.0015% @ 32Ω Output Power ~60mW - 65mW @ 32Ω Output Impedance ~0.5Ω to 10Ω (variant dependent) USB Type-C (Input) to 3.5mm or 4.4mm (Output) Common Implementation Features

The Conexant CX31993 is a high-performance USB-C DAC/Amp chip widely used in ultra-portable dongles (often branded as "CX-Pro" or "Abigail"). While it is praised for its high sampling rate and low cost, users often seek "fixes" for issues like high-frequency harshness or low driving power for demanding headphones. CX31993 Key Specifications These specs are standard across most CX31993-based devices: Resolution: Up to 32-bit / 384kHz PCM. Signal-to-Noise Ratio (SNR): >128dB. Dynamic Range (DNR): >120dB.

Output Power (Thrust): Typically 65mW @ 32Ω (approx. 1Vrms). Total Harmonic Distortion (THD+N): 0.0003% (-95dB). "Fixes" & Performance Optimizations

If you are experiencing issues with a CX31993 dongle, consider these common "better fix" solutions: Any link to the cx31993 datasheet? - Facebook cx31993 datasheet fix better

Where to Get the Real Datasheet

The actual CX31993 is made by Conexant (now Synaptics). You cannot get it publicly – it's under NDA. The chips in USB dongles (Apple dongle uses CX31993 clone) are custom variants.

Reliable alternatives:

• Realtek ALC5686 – public datasheet available
• Savitech SA9312 – better documentation
• ESS ES9280A – full public datasheet

Part 1: The Missing Datasheet – What We Know

Unlike open chips from Texas Instruments or ESS, the CX31993 is a "black box." Because Conexant focuses on OEM contracts (laptop manufacturers like Dell, HP, and Lenovo), they do not publish public datasheets. Part 1: The Missing Datasheet – What We

The reverse-engineered specs (community aggregated):

• DAC Architecture: 32-bit Sigma-Delta
• SNR (Signal-to-Noise Ratio): 118dB (claimed) / ~115dB (measured)
• Output Power: 1Vrms (standard) / 2Vrms (some implementations with separate amp)
• THD+N: -95dB typical
• Pinout: USB controller + DAC + AMP in single QFN-20 package.

Why you need a "fix": Without the datasheet, manufacturers often copy reference designs incorrectly. This leads to:

• Incorrect I2C register settings for headphone impedance detection.
• Broken UAC 2.0 (USB Audio Class 2.0) fallback modes.
• Non-functional hardware volume buttons on the dongle.

2. The Decoupling Myth

The problem:
The datasheet shows only 1µF + 0.1µF on VDD.

The fix:
That’s insufficient for low noise floor. Use this proven network: cx31993 datasheet fix better

VBUS (5V) → 10µF ceramic (X5R) → 0.1µF (0402) → 1nF (high-freq noise)
               ↓
          CX31993 VDD pin

Place the 1nF closest to the pin. This reduces hiss by ~12dB on sensitive IEMs.

Part 4: Is the CX31993 Better than the Competition?

Without a datasheet, it feels risky. But after "fixing" the driver issues:

| Feature | CX31993 (Fixed) | Apple A2049 (C100) | Realtek ALC5686 | | :--- | :--- | :--- | :--- | | Max Bit Depth | 32-bit | 24-bit | 32-bit | | Max Sample Rate | 384kHz | 48kHz (locked) | 384kHz | | Output Impedance | ~2Ω (very good) | ~0.9Ω (better) | ~10Ω (worse) | | Power Draw | 35mA (fixed) | 25mA | 45mA |

Verdict: A properly fixed CX31993 beats the Apple dongle for high-res listening because the Apple dongle is hardware-capped to 48kHz on Android/Windows unless you use expensive apps.