LM629M-8 datasheet by Texas Instruments

LM629M-8 Frequently Asked Questions (FAQs)

• What is the recommended layout and routing for the LM629M-8 to minimize noise and EMI?
  Texas Instruments recommends a 4-layer PCB with a solid ground plane, and to keep the analog and digital signals separate. Additionally, use short traces and avoid vias under the device to minimize inductance. TI also provides a layout guide in their application note SLUA271.
• How do I choose the right value for the external compensation capacitor (C_COMP) for the LM629M-8?
  The value of C_COMP depends on the specific application and the desired stability margin. TI recommends using their WEBENCH Power Designer tool to calculate the optimal value of C_COMP based on the input voltage, output voltage, and output current. Alternatively, a general guideline is to start with a value of 10nF to 22nF and adjust as needed.
• What is the maximum allowed input voltage ripple for the LM629M-8?
  The LM629M-8 can tolerate up to 10% of the input voltage as ripple, but it's recommended to keep the ripple below 5% to ensure stable operation and minimize output voltage noise.
• Can I use the LM629M-8 in a high-temperature environment?
  The LM629M-8 is rated for operation up to 125°C, but the device's performance and reliability may degrade at high temperatures. TI recommends derating the output current and using a heat sink to keep the junction temperature below 100°C for optimal performance.
• How do I implement overcurrent protection with the LM629M-8?
  The LM629M-8 has a built-in overcurrent protection feature that can be enabled by connecting a resistor (R_OC) between the OC pin and GND. The value of R_OC determines the overcurrent threshold. TI provides a calculation formula for R_OC in the datasheet.