Cx31993 Datasheet Fix

Audio plays correctly, but a constant high-pitched whine or PC activity noise is audible in sensitive In-Ear Monitors (IEMs).

The CX31993 features an internal low-dropout (LDO) regulator. It requires a dedicated 1.0µF to 2.2µF decoupling capacitor to ground to stabilize the core logic. USB Interface

Implement an anti-pop circuit using a delayed-connect PMOS switch on the audio output lines. Incorrect ADC threshold configuration.

Keep a "silence" track playing in the background or use an app that keeps the USB bus active. 3. Troubleshooting Connection Issues Cx31993 Datasheet Fix

High inrush current or lack of proper CC (Configuration Channel) pull-down resistors on the USB-C receptacle. If you are building a custom board with a USB-C receptacle, the upstream device will not output 5V VBUS unless it detects the proper resistance on the CC lines.

A Closer Look at the CX31993 Datasheet Fix – Clarifying the Specs for a Popular USB DAC Chip

Audio distortion or low volume when connecting low-impedance (16-ohm or 32-ohm) headphones. Audio plays correctly, but a constant high-pitched whine

Add a small passive low-pass filter (typically a 10Ω to 22Ω resistor in series, followed by a 100pF capacitor to ground) on HPL and HPR to suppress residual delta-sigma modulator noise without altering the audible frequency spectrum. 4. Firmware and Software Configuration Note

Fixing issues with the (a popular high-performance Conexant USB-C DAC chip) typically involves addressing "datasheet" errors in how the operating system or player app interprets the hardware's capabilities rather than a physical modification. 1. Fix Audio Static & Stuttering (Bit-Perfect Mode)

The Conexant (now Synaptics) Cx31993 is a highly popular, low-cost, and high-performance USB Type-C digital-to-analog converter (DAC) chip. It is widely used in portable headphone dongles, audio adapters, and DIY audio projects because of its impressive signal-to-noise ratio (SNR) and low power consumption. However, engineers and DIY hobbyists often encounter documentation gaps, hardware initialization failures, and stability issues when working with this chip. USB Interface Implement an anti-pop circuit using a

To get the best out of the CX31993, you need to bypass the Windows audio mixer (which re-samples everything to 48kHz).

pin, implement a 10kΩ pull-down resistor to ensure the chip registers a completely disconnected state when the headphones are unplugged. 📈 Reference Schematic Checklists