ADP5034 passive components

Can I use different output capacitors and inductors values beside the one suggested in the ADP5034 datasheet?

  • 0
    •  Analog Employees 
    on Apr 28, 2011 4:11 AM

    It is possible to increase the output capacitance for each buck up to 40uF but cannot be below 7uF, it is important to know the capacitance de-rating with the applied voltage especially when using small case size (below 0805) and applied voltage approaching the capacitor rated voltage. It is important also to consider additional capacitors distributed across the rail, it is typical for example to add several capacitors in parallel close to the load to improve the noise bypassing. Above 40uF or below 7uF there is risk to make the buck regulator unstable. The recommended inductor value is 1uH, it is possible to increase this value up to 2.2uH in case the inductor ripple current need to be minimized. Pay attention when using small inductors, especially multilayer types because the inductance value will decrease sharply when the DC current is increase, smaller inductance will increase the ripple current which in extreme cases may hit the current limit.

    The LDOs are less sensitive to different capacitor value and it is stable for a large ESR range, increase the output capacitance only if needed, for example to support a high transient with minimal drop, in this situation it is better to parallel capacitors instead of having one larger capacitor this is because paralleling capacitors will reduce the ESR which is the primary reason for the voltage drop cause by a transient.

  • 0
    •  Analog Employees 
    on Jan 21, 2019 9:01 PM

    Answered and Closed