Add to both CC1 and CC2 pins on the USB-C plug. Intermittent Audio Dropouts USB power sagging or high ESR caps.
The has become a legendary chip in the budget audiophile community, powering popular USB-C DAC dongles like the Abigail and JCALLY JM6 . However, finding an official, high-quality CX31993 datasheet is notoriously difficult, as the documentation is often restricted to original equipment manufacturers (OEMs).
The pinout diagram in certain revisions of the datasheet mislabels the internal low-dropout (LDO) regulator outputs. Swapping these connections results in the digital core or the analog stage receiving unstable voltages, causing intermittent chip resets. 2. Flawed Charge Pump Capacitor Values
The internal amplifier of the CX31993 is sometimes pre-configured to output max gain, boosting the inherent noise floor of highly sensitive multi-driver IEMs. Cx31993 Datasheet Fix
Are you experiencing a or looking for pinout diagrams for a DIY project? Any link to the cx31993 datasheet?
Check the negative voltage rail generated by the chip. Measure the voltage at the charge pump output pin. If it is not reading approximately -1.8V to -2.5V, your flying capacitor is shorted, oriented incorrectly (if using polarized caps, though ceramic is recommended), or damaged. There is a constant high-pitched whine in the background
Connect this pin directly to the audio jack ground sleeve. Do not tie it directly to the noisy digital ground plane; use a dedicated analog ground kelvin connection. 3. Step-by-Step Fixes for Common CX31993 Problems Fix 1: Resolving Connection and Recognition Failures Add to both CC1 and CC2 pins on the USB-C plug
Solder a 0.1µF ceramic capacitor in parallel with a 10µF tantalum capacitor as close to the VDDcap V sub cap D cap D end-sub
Ensure you have two separate 5.1kΩ resistors (one on CC1 to GND, one on CC2 to GND). Never tie CC1 and CC2 together to a single resistor.
: Standard datasheets often suggest a 1µF or 4.7µF capacitor without specifying the ESR (Equivalent Series Resistance). High ESR capacitors here will cause a noticeable background hiss. Audio Output Stage and DC Blocking such as Wavelet
Cross-check the information with other sources, such as technical forums or manufacturer websites.
On , bypass the native Android audio stack by using media players with direct USB drivers, such as Wavelet, USB Audio Player Pro (UAPP), or Hiby Music. 3. Optimizing Audio Quality: Eliminating the Noise Floor