SI3402-B-GM QFN 20_5x5mm datasheet

Si3402B evaluation board controller design guide

Detailed Functional Explanation of Si3402B Circuit:

Detailed Specification Highlights of Si3402B Chip:

si3402-b-gm qfn 20_5x5mm​ reference design​

FAQ

1. What is the pin configuration for the Si3402-B-GM (QFN-20) package?

The Si3402-B-GM uses a QFN-20 package (5mm × 5mm), featuring 20 bottom-side pins with a central thermal pad to enhance heat dissipation. Proper PCB layout should include thermal vias and sufficient copper areas for effective cooling.

2. What should I pay attention to when using the Si3402-B evaluation board?

Ensure the input power source complies with IEEE 802.3af standards (such as a compliant PSE switch or mid-span injector).

Connect an appropriate load at the output (e.g., 5V load) to accurately evaluate the board’s performance.

Verify jumper configurations and settings according to your specific evaluation requirements before first-time use.

3. How should I optimize the feedback loop in an Si3402 controller design?

Use a TL431 and optocoupler feedback network for precise and stable voltage regulation.

Place feedback network components close to the Si3402 feedback pins to minimize noise.

Select feedback resistors with tight tolerances (±1%) to ensure accurate output voltage regulation.