Cx31993 Datasheet Fix Hot |verified| Access

Instead of modifying the dongle (which is impractical), . The goal is to reintroduce a gentle low-pass filter and impedance matching. Apply one of these two verified solutions:

Do this if the chip runs hot even with fixes A & B applied.

The measured thermal resistance ($R_\theta JA$) was found to be , 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.

The Conexant CX31993 is a marvel of budget audio engineering. The datasheet is technically correct that the chip is "low power"—from a silicon perspective. But the physical packaging, cheap LDOs, and lack of thermal management in $5 dongles make the user experience "hot." cx31993 datasheet fix hot

Ensure the dongle is not trapped under a phone case or in a tight pocket while in use. Allowing airflow around the metal chassis can significantly reduce surface temperature. Conclusion: Is the Heat a Problem?

The device was powered on and subjected to a sustained computational load representing 80% maximum throughput. Ambient temperature was maintained at 25°C. Temperature was monitored until thermal equilibrium was achieved.

If your chip is hot despite doing everything right electrically, you need to implement a . This is where the "modding" community shines. Instead of modifying the dongle (which is impractical),

The CX31993 has internal registers that control bias currents. By default, some implementations run the headphone amp in "high performance" mode (8mA bias) instead of "low power" (2mA bias). This is adjustable via I²C (pins 14=SDA, 15=SCL).

But when you plug in headphones (32 Ohm or lower), or use a passive analog volume control (like a USB knob), the amplifier enters a Class A/B bias region where efficiency plummets.

This public link is valid for 7 days and shares a thread, including any personal information you added. This link or copies made by others cannot be deleted. If you share with third parties, their policies apply. Can’t copy the link right now. Try again later. The measured thermal resistance ($R_\theta JA$) was found

The QFN-20 package has an exposed thermal pad (pin 21, center). The datasheet mandates: "The thermal pad must be soldered to a ground plane with at least 6 vias to the opposite layer." Most low-cost PCBs have no vias, only a small pad. Heat gets trapped inside the chip.

The official Conexant (now Synaptics) CX31993 datasheet lists the chip as a "high-performance, low-power audio codec." The keyword is low power . The sheet claims a typical current consumption of for the digital-to-analog conversion.

Despite this, the CX31993 remains one of the best budget audio solutions on the market for its superior audio performance, making the slight thermal management worth the effort.

: If the dongle becomes "burning hot" almost instantly, it likely has a manufacturing defect or internal short. In these cases, it is safer to return the unit for a replacement. Common Specs & Performance Specification Sampling Rate 32-bit / 384kHz Power Output My solution to overheating DAC dongles - HifiGuides Forums