Hot - Cx31993 Datasheet Fix

Conexant CX31993 is a widely utilized, high-performance Class G audio DAC (Digital-to-Analog Converter) chip often integrated into affordable USB-C dongles. While praised for its 32-bit/384kHz sampling rate and neutral sound signature, some users experience overheating issues, which can lead to audio artifacts like static or hiss. Understanding the Overheating Problem

  • VCC: Supply voltage (typically starts around 15V-20V).
  • OUT: Driver output for the MOSFET.
  • RT/CT: Timing components for the switching frequency.

The measured thermal resistance ($R_\theta JA$) was found to be 95°C/W, nearly three times the value stated in the datasheet. The datasheet value was likely derived using a high-conductivity JEDEC test board with generous copper spreading, which is physically impossible in the compact form factors where the CX31993 is typically deployed. cx31993 datasheet fix hot

Implementation Flaws: Budget designs may lack proper heat dissipation (heatsinks or thermal pads), causing the zinc alloy or plastic shells to become hot to the touch during extended use. VCC: Supply voltage (typically starts around 15V-20V)

  1. Locate the traces from L_OUT (pin 18) and R_OUT (pin 17) to the headphone jack.
  2. Cut the trace near the chip. Insert a series RC network: 10Ω in series, then 100nF from the amp-side of the 10Ω to GND. (Better: place 10Ω in series, and 100nF from the output side of the 10Ω to GND).
  3. Repeat for both channels.
    Result: Zobel network kills oscillation. Amp current drops to datasheet values.

(like the Abigail, CX-Pro, or JCally JM6) is heating up or behaving poorly, you aren't alone. Here is the breakdown of why this happens and how to handle it. 1. The "Heat" Problem: Why it Happens Power Mismatch: Users have reported that the CX31993 (often paired with a The measured thermal resistance ($R_\theta JA$) was found

The Real Issue with the Spark (CX31993 + MAX97220) : r/iemlndia

If your DAC is reaching temperatures over 50°C, you can implement external cooling: Apply Heatsinks : Users on the HifiGuides Forums