Cx31993 Datasheet ((better)) May 2026

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). cx31993 datasheet

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). OEM Portal: If you are a manufacturer ordering

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

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 Pin Configuration The datasheet would provide a detailed

Part 9: Where to Obtain the Official Datasheet

The "CX31993 datasheet" is not publicly available on Synaptics’ website due to confidentiality agreements. To get the full 50-page document (including register map and timing diagrams):

1. OEM Portal: If you are a manufacturer ordering >10k units, request access via the Synaptics/Conexant distributor network (e.g., Arrow or Avnet).
2. Archive.org: Archived versions of the original Conexant site sometimes have the CX31993 Product Brief (3 pages), but not the full datasheet.
3. GitHub: Open-source USB audio projects (like QMK or Zaphod Audio) often have reverse-engineered header files that act as a pseudo-datasheet for the I2C registers.

Pin Configuration

The datasheet would provide a detailed pinout describing each pin's function, such as:

• Audio Inputs: For connecting to stereo audio sources.
• Audio Outputs: For connecting to a power amplifier or a recording device.
• Control Inputs: For features like surround level, center width, and panorama mode adjustments.
• Power Supply and Ground: Essential for powering the chip.

Product overview

• Part: CX31993
• Device class: Single-chip, high-performance NTSC/PAL analog video decoder (composite/S-Video/YC and CVBS), with integrated ADCs and video processing.
• Typical application: Set-top boxes, DVD players, DVRs, video capture cards, CCTV front-ends, multimedia appliances needing analog video input and digitization.

Part 2: Electrical Specifications (The Hard Numbers)

This is the section most visitors looking for the "CX31993 datasheet" care about. Here is the verified performance data based on OEM testing and reverse-engineered specifications.

| Parameter | Condition | Min | Typ | Max | Unit | | :--- | :--- | :--- | :--- | :--- | :--- | | Supply Voltage (VBUS) | USB-C Spec | 4.4 | 5.0 | 5.5 | V | | Quiescent Current | No audio | - | 15 | 25 | mA | | Dynamic Current | 1Vrms output | - | 35 | 45 | mA | | Output Load Impedance | Stereo out | 16 | 32 | 600 | Ω | | Output Voltage (RMS) | 1% THD limit | - | 1.0 | 1.2 | Vrms | | Crosstalk | 1kHz signal | - | -85 | - | dB | | Frequency Response | 20Hz - 20kHz | +/-0.1 | Flat | +/-0.5 | dB |

PCB Layout Guidelines (From Synaptics Application Notes)

• Separation: Keep the USB D+/D- traces (90-ohm differential impedance) away from the analog output traces.
• Grounding: Use a split ground plane. Connect AGND (Pin 6) and GND (Pin 2) at a single point under the chip via a 0-ohm resistor.
• ESD Protection: Add a 5V TVS diode on VBUS and a USBLC6-2SC6 for the data lines.

Performance specs (typical)

• Signal-to-noise ratio (SNR): High SNR in luma/chroma paths (specific dB figures vary by revision; consult full datasheet).
• Input clamp and black-level restoration: On-chip clamp with programmable timing and thresholds.
• Sampling clock rates: Internal PLL generating required sampling clocks (e.g., 27 MHz/54 MHz multiples or derived rates) — configurable for different output bus widths and formats.
• Color space conversion accuracy: Programmable coefficients for RGB↔YCbCr with fixed-point math; typical error and chroma phase specs provided in full datasheet.

The "No Pop" Feature

Datasheet references highlight an integrated power-on-reset (POR) sequence that mutes the amplifier until the DAC is fully locked. This prevents the loud "POP" noise typically heard when plugging a cheap dongle into a PC.

1. Key Specifications (What to look for in the datasheet)

| Parameter | Typical Value | Relevance | |-----------|---------------|------------| | Supply Voltage | 3.3V – 5V (from VBUS) | USB bus-powered; no external battery | | DAC Resolution | 32-bit | High-resolution audio support | | Sampling Rates | 44.1, 48, 88.2, 96, 176.4, 192 kHz | Covers standard to high-res | | Output Power | Up to 1.25Vrms (2Vrms with external boost) | Drives most IEMs and some headphones | | Headphone Impedance | 16Ω – 300Ω | Versatile load handling | | SNR (DAC) | >120 dB | Very low noise floor | | THD+N | <0.001% | Clean, distortion-free output | | Current Consumption | ~20 mA (active), <1 μA (standby) | Low power for mobile use | | Interface | I2S, TDM, PDM (digital mic input) | Flexible digital audio input |