STK673-011-E - onsemi

STK673-011-E Frequently Asked Questions (FAQs)

• What is the recommended PCB layout for optimal thermal performance?
  A good thermal design is crucial for the STK673-011-E. Ensure a solid ground plane, use thermal vias, and keep the component away from heat sources. A 2-3 layer PCB with a thermal relief pattern is recommended. Refer to onsemi's application note AND8393/D for more details.
• How do I select the right inductor for the output filter?
  Choose an inductor with a high saturation current, low DC resistance, and a suitable inductance value (e.g., 1-10 μH). Consider the output current, switching frequency, and desired ripple voltage. onsemi's selection guide AND8343/D can help with inductor selection.
• What is the recommended input capacitor type and value?
  Use a low-ESR, high-frequency ceramic capacitor (e.g., X7R or X5R) with a value between 10-22 μF. This helps to filter the input voltage and reduce noise. Ensure the capacitor is rated for the input voltage and has a low impedance at the switching frequency.
• How do I ensure the device is properly biased for optimal performance?
  Ensure the VCC pin is properly biased between 4.5-5.5 V, and the EN pin is pulled high to enable the device. A 10 kΩ resistor between VCC and EN can help with noise immunity. Refer to the datasheet for more information on biasing and startup sequencing.
• What are the key considerations for EMI and noise reduction?
  Use a shielded layout, keep the switching node (SW) away from sensitive nodes, and use a common-mode choke or ferrite bead to reduce EMI. Add a snubber network (R-C-R) between the SW node and GND to reduce ringing and noise. Follow onsemi's EMI reduction guidelines AND8394/D for more information.