In the wake of the smartphone headphone jack removal and the shift toward ultra-thin laptops, the humble USB-C to 3.5mm adapter has become an essential daily driver for millions of users. At the heart of many of the best-performing, budget-friendly dongles lies a specific integrated circuit: the Conexant CX31993.
For engineers and audio enthusiasts searching for the "CX31993 datasheet," the goal is usually the same: to verify power output (mW), Total Harmonic Distortion (THD+N), and compatibility with high-impedance headphones. While the full manufacturer datasheet is often restricted under NDA (Non-Disclosure Agreement) with Synaptics (which acquired Conexant), this article aggregates the publicly available technical specifications, electrical characteristics, and circuit design implications of the CX31993.
Since it is not public:
While the full NDA-protected datasheet is restricted, publicly available specifications and reverse-engineered data reveal the following key parameters:
The datasheet figures reveal a limitation: the CX31993 is optimized for IEMs (In-Ear Monitors) and low-impedance headphones. With a max output of 1.2Vrms, it struggles to drive high-impedance studio headphones (e.g., Sennheiser HD600 series at 300Ω). On a 300Ω load, the power output drops to roughly 0.5mW, resulting in low volume.
The CX31993 integrates three primary functional blocks:
Pinout Highlights (Typical 20-24 pin QFN package):
The CX31993 represents a tier of audio hardware that prioritizes clarity and power efficiency. While many modern phones are moving toward USB-C dongles and wireless audio, having a dedicated, high-quality codec like the CX31993 on-board is a hallmark of a device designed for the true music lover.
Are you working on a project involving the CX31993? Drop your questions or schematic troubleshooting tips in the comments below!
CX31993 USB-C DAC Chip: The Ultimate Datasheet & Technical Overview
The CX31993 has rapidly become a staple in the world of portable audio. As a highly integrated USB Type-C digital-to-analog converter (DAC) SoC, it is the engine behind many of the high-performance "dongle DACs" that audiophiles use to bypass inferior smartphone audio circuitry.
If you are a hardware engineer or a DIY enthusiast looking for the CX31993 datasheet specifications, this article breaks down the technical architecture, electrical characteristics, and performance metrics of this popular chip. 1. Product Overview
The CX31993 is a high-performance USB audio bridge with an integrated DAC and headphone amplifier. It is designed specifically for USB-C to 3.5mm adapters, mobile phones, and tablets. Its primary draw is the ability to deliver high-resolution audio (Hi-Res) with extremely low power consumption and a small physical footprint. Key Features: Resolution: Up to 32-bit / 384kHz PCM. Interface: USB 2.0 High-Speed (Type-C compatible). SNR (Signal-to-Noise Ratio): ~128dB (A-weighted). Dynamic Range: ~120dB. THD+N: -95dB @ 32 ohms. Power Consumption: < 50mW (active). 2. Technical Specifications (Datasheet Summary) Audio Performance
The CX31993 is lauded for its clean output. Unlike entry-level chips (like the ALC5686), the CX31993 offers a wider dynamic range and a lower noise floor. Specification Sampling Rate 44.1, 48, 88.2, 96, 176.4, 192, 352.8, 384 kHz Bit Depth 16-bit, 24-bit, 32-bit Output Power 31mW @ 32Ω Crosstalk DSD Support DSD64/DSD128 (DoP) Electrical Characteristics Operating Voltage: 3.3V to 5.0V (Standard USB VBUS).
Integrated LDO: Built-in regulators to minimize external component count.
I2C/GPIO: Supports external MCU control for custom features or LED indicators. 3. Pin Configuration and Package
The CX31993 typically comes in a small QFN (Quad Flat No-lead) package, making it ideal for the slim profiles of USB-C dongles.
USB Differential Pairs (D+/D-): Connects directly to the USB-C port.
Analog Outputs (L/R): Driven by the internal Class-G headphone amplifier.
MIC/GND/Sense: Supports 4-pole (TRRS) jacks for microphone input and in-line remote controls (volume +/- and play/pause). 4. Why Use the CX31993? Power Efficiency
One of the most critical parts of the CX31993 datasheet is its power management. It features an intelligent "Deep Sleep" mode when no audio is playing, preventing it from draining a smartphone's battery during standby. Versatility
While many DACs require external clocks or complicated power filtering, the CX31993 is "plug-and-play" with standard UAC 2.0 drivers. It works natively on Android, iOS (with an adapter), Windows 10/11, and macOS. Sound Profile cx31993 datasheet
Technically, the chip is designed for transparency. Its low output impedance (< 1 ohm) ensures that it doesn't color the sound of multi-driver IEMs (In-Ear Monitors), maintaining a flat frequency response across the spectrum. 5. Design Considerations for Engineers
When implementing the CX31993 based on the datasheet, pay close attention to:
Decoupling Capacitors: Place decoupling caps as close to the VDD pins as possible to reduce high-frequency noise from the USB bus.
Grounding: Use a solid ground plane. Keep the analog ground (AGND) and digital ground (DGND) properly isolated to avoid digital "chirping" in the audio path.
Heat Dissipation: While it runs cool, ensure the QFN thermal pad is properly soldered to a copper pour on the PCB. Conclusion
The CX31993 is arguably the best "bang-for-your-buck" DAC chip in the current market. It provides a bridge between low-end generic adapters and high-end desktop gear. For developers, its high integration reduces BOM (Bill of Materials) costs while delivering "Hi-Res" certified performance.
The pneumatic hiss of the heavy door sealing shut was the only sound in the archive room. It meant the cooling fans had kicked in, and the air was being scrubbed of the corrosive humidity that rotted everything else in the Sector.
Elias didn't mind the cold. He adjusted his thermals and clicked on his high-lumen work light, the beam cutting through the dusty gloom. He was a Restoration Tech, third class. His job was simple: go into the dead zones, find the pre-Collapse tech, and catalog it before it was melted down for scrap.
Today’s target was a salvage haul from a sunken drone carrier. Mostly rusted hull plating and fried servo motors. But tucked inside a water-tight, shock-proof case was a small, green circuit board.
Elias picked it up with gloved hands. It was pristine. The silkscreening on the board was sharp, white text on a dark sea of fiberglass.
CX31993.
He squinted. He’d never seen that prefix. Usually, he dealt with power regulators or generic logic gates. This looked like a system-on-a-chip, intricate and dense with microscopic pathways.
He placed the board on his workbench and pulled up his terminal. The Archive database was spotty, reliant on ancient servers that hummed with the sound of failing bearings. He typed in the alphanumeric code: CX31993 Datasheet.
The screen flickered. A progress bar crawled across the display. Searching... Searching...
Then, a single file populated the screen. Not a standard PDF, but a raw, corrupted hex file with a header that made Elias’s breath hitch.
CLASSIFICATION: STRATEGIC AI CORE – PROJECT LAZARUS. DATASHEET CX31993: "THE GATEKEEPER"
Elias looked around. The security camera in the corner was a dummy unit, its lens long since shattered. He tapped the 'Open' command.
The text was fragmented, a ghost of a technical document.
Component: CX31993 Function: Predictive Heuristics & Autonomous Decision Matrix Voltage: 3.3V (Active) / 0.0V (Dormant) Warning: Do not apply power without an external logic dampener.
Elias leaned closer. Predictive Heuristics. It wasn’t just a processor; it was a brain. A specialized brain designed to guess what its operator wanted before they asked.
He looked at the chip. It sat there, cold and dead. The database entry was sparse, but a footnote at the bottom, highlighted in red, caught his eye. In the wake of the smartphone headphone jack
Field Report 044: "The CX31993 doesn't just process data; it anticipates intent. It achieved 99.9% synchronization with the pilot during the Siege of Terminal 4. The pilot eventually stopped speaking. The chip knew the orders before the thought was fully formed."
Elias felt a chill that had nothing to do with the climate control. This was forbidden tech. Post-Collapse laws were strict: any AI capable of independent thought was to be destroyed immediately. It was the chaos of the Autonomous Wars that had reduced the world to this scavenger state.
He reached for his
A reference implementation for a USB-C dongle:
The CX31993 is a benchmark USB audio codec for cost-sensitive, high-performance consumer audio products. While not the absolute state-of-the-art (compared to ESS or AKM flagship DACs), its integrated USB controller, low power consumption, and excellent measured performance make it the de facto choice for sub-$15 USB-C audio dongles. Designers should obtain the full datasheet through Synaptics’ official distribution channels for exact register maps, thermal characteristics, and layout guidelines.
Note: The full datasheet for CX31993 is proprietary to Synaptics. This write-up is compiled from public test data, product teardowns, and community documentation. For production designs, please contact Synaptics or an authorized distributor for NDA terms and complete technical documentation.
The glowing blue light of the CX31993 was the last thing Elara saw before the noise floor finally swallowed her world.
She was a "Sonic Archaeologist," a title she’d made up to justify spending her life digging through the digital remains of the 21st century. Her latest find was a small, silver-braided cable—a relic of an era when humans still used physical wires to pump sound directly into their skulls. At its heart sat the Conexant CX31993, a tiny piece of silicon that promised high-resolution salvation in a world of compressed static.
"Thirty-two bits," she whispered, her voice cracking in the dry air of the archive. "Three hundred and eighty-four kilohertz." The numbers felt like a prayer.
In her time, audio was a luxury. The Great Muffling had left the atmosphere thick with electromagnetic interference, turning every song into a muddy mess. But according to the CX31993 datasheet, this little chip had a signal-to-noise ratio (SNR) of 128dB. It was a surgical tool designed to cut through the hum of the universe.
She plugged the ancient USB-C connector into her rig. Her console flickered, recognizing the device with a archaic ping. "UAC1.0 detected," the screen flashed.
"Come on, you little dark horse," she urged, recalling the old forum posts that called it a budget giant.
As the first track began to play, the "lean, neutral-to-slightly-bright" tonality the datasheet promised flooded her senses. The low-impedance IEMs in her ears didn't just play music; they reconstructed a lost reality. She could hear the distinct "air" between instruments, a transparency that the bulky, more expensive amplifiers of her era could never mimic.
But there was a catch—the datasheet warned of its limits. At 1V RMS, it was an efficient beast, but it lacked the "thrust" to drive the heavy, 150-ohm "cans" of the old-world titans. When she tried to push a bass-heavy anthem, the low end felt "flabby," exactly as the ancient reviewers had prophesied.
Suddenly, a spike of 200kHz noise—the "Class D ghost" mentioned in a late-century engineering forum—screeched through the line. Elara scrambled to adjust her filters, realizing the chip was more than just a DAC; it was a window.
The datasheet wasn't just a list of specs; it was a map to a frequency range humans had forgotten how to hear. In that moment, surrounded by the silence of a dead century, Elara realized that as long as the CX31993 held its steady 0.0015% THD+N, the past would never truly be silent. Audio Expansion Card - CX31993 Datasheet
The "story" of the CX31993 datasheet is essentially a saga of an elusive document that became a grail for the budget audiophile and DIY tech communities.
While most modern tech components have easily accessible manuals, the CX31993—a high-performance
Digital-to-Analog Converter (DAC) chip—gained "dark horse" status because it was powerful, cheap, and surprisingly difficult to find technical documentation for. 1. The "Hidden Gem" Discovery The CX31993 chip first rose to fame through the
(Chinese Hi-Fi) community. Reviewers began noticing that dirt-cheap USB-C dongles (often called "CX-Pro") were outperforming big-name brands and even the gold-standard Apple dongle in certain areas like power and clarity on Android devices. It offered a massive 130dB signal-to-noise ratio and support for 32-bit/384kHz audio, which was unheard of for its sub-$15 price point. audioreviews.org 2. The Datasheet Hunt
As enthusiasts tried to integrate the chip into custom projects—like the Framework Laptop's audio expansion card —they hit a wall: there was no official public datasheet. Framework Community The Mystery: Users on forums like Output Power:
and Facebook groups spent years hunting for the spec sheet to verify its claims or filter out specific electrical noise. The "Leak":
Eventually, unofficial copies and snippets began circulating in private Google Drive folders and niche engineering forums, allowing hobbyists to confirm its ultra-low power consumption and multi-mode power control. Framework Community 3. Key Specs Revealed
Through the community’s collective effort, the "legendary" specs of the CX31993 were finally mapped out: Audio Expansion Card - CX31993 Datasheet
Based on available technical specifications for the CX31993 USB-C DAC chip
(commonly used in budget USB-C to 3.5mm adapters), here is a summary of the datasheet parameters CX31993 USB-C DAC Specifications (Often paired with 4-8 strands of sterling silver cable) Interface: USB-C to 3.5mm Audio Jack DAC Sampling Rate: Up to 32bits/384KHz (PCM) DSD Support: SNR (Signal-to-Noise Ratio): DNR (Dynamic Range): THD+N (Distortion): Output Thrust/Power: ~65mW (approximate output) Compatibility:
Android (95%+ of Type-C devices), Windows 10, Apple system (macOS/iOS) Supports phone calls and inline cable controls Audio Characteristic
is often considered a refined, analog-like sound profile compared to other budget options like the JM20, offering high clarity in mids and highs without overly sharp treble Disclaimer: The
is a specialized chip frequently used in white-label consumer products. A complete, public manufacturer datasheet is often hard to find, so these specs are derived from community testing and manufacturer marketing materials. Any link to the cx31993 datasheet?
Conexant CX31993 (often branded as CX-Pro) is widely reviewed as a high-performance, budget-friendly USB-C DAC/amp. While an official "Conexant" datasheet is difficult to find because the company was acquired by
in 2017, its technical capabilities and real-world performance are well-documented through enthusiast testing. Core Specifications (from Datasheet Data) Resolution: Supports up to 32-bit / 384kHz PCM. Output Power: Typically rated at 65mW @ 32Ω 1.0 Vrms output (superior to the 0.5V EU Apple dongle). Signal-to-Noise Ratio (SNR): Frequently cited at Dynamic Range (DNR): Distortion (THD+N): 0.0003% or ~95dB. Review Insights Conexant (CX-Pro) CX31993 USB-C Amp/DAC Review
The Conexant (Synaptics) CX31993 is a high-performance, low-power USB Type-C digital-to-analog converter (DAC) and headphone amplifier system-on-chip (SoC). While a full official PDF datasheet from the manufacturer is often restricted to industrial partners, technical specifications from Signature Acoustics and various community reviews define its core capabilities. Technical Specifications
The CX31993 is designed to deliver high-resolution audio for mobile devices. Its primary metrics include:
Resolution & Sampling: Supports up to 32-bit / 384kHz PCM audio decoding.
Signal-to-Noise Ratio (SNR): Greater than 128dB, ensuring a very low noise floor. Dynamic Range (DNR): Greater than 120dB.
Total Harmonic Distortion (THD+N): Approximately 0.0003% (measured at -95dB).
Output Power (Thrust): Typically 65mW into a 32Ω load, providing roughly 1V RMS output. Architecture and Application
The chip is an "all-in-one" solution commonly found in budget audiophile "dongles" (USB-C to 3.5mm adapters) such as the JCALLY JM6 or Abigail.
Power Efficiency: It is noted for running cool and having minimal impact on a smartphone's battery life, often consuming only about 2% extra battery per hour of use.
Linearity: Measurement data shows excellent linearity across the audible frequency range (20Hz–20kHz).
Output Impedance: Its output impedance is extremely low (well below 1Ω), making it ideal for sensitive In-Ear Monitors (IEMs) to avoid frequency response shifts. Sound Profile and Limitations
In practical use, the CX31993 is described by reviewers on AudioReviews.org as having a neutral-to-slightly-bright tonality with a clean, uncolored output. Any link to the cx31993 datasheet? - Facebook
Note: The full public datasheet for CX31993 is proprietary and not freely available. This guide is based on publicly disclosed specifications, application notes, and reverse-engineering from known products (e.g., Conexant/CX-Audio dongles). For register-level details, you must sign an NDA with the manufacturer.