SLOA198A September 2014 – December 2021 DRV2665 , DRV2667 , DRV2700 , DRV8662
The inductor plays a critical role in the performance of the DRV8662, DRV2700, DRV2665, and DRV2667, so selecting and testing a suitable inductor is important to ensure the best performance.
An inductor can be described with relatively few parameters. The following table shows the typical parameters listed in an inductor datasheet:
Part Number | Inductance (µH) | DC Resistance (Ω) | ISATURATION (A) | IRMS | SRF (MHz) |
---|---|---|---|---|---|
CIG22E3R3SNE | 3.3 | 0.200 | 1.1 | 1.30 | 42 |
DEFINITIONS |
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Inductance – the primary functional parameter of an inductor. |
DC Resistance (DCR) – the resistance in the inductor due to the wire |
ISATURATION or Saturation Current – the peak current flowing through the inductor that causes the inductance to drop due to core saturation. |
IRMS or RMS Current or Thermal Current – the amount of continuous RMS current flowing through the inductor that causes the maximum allowable temperature rise. |
SRF or Self Resonant Frequency – the frequency at which the inductance of the inductor winding resonates with the capacitance of the inductor winding. |
To help narrow the number of inductors quickly, begin by looking at these three parameters:
Inductor current ratings are always the biggest source of confusion when selecting an inductor, because there are multiple, non-standardized current ratings to look for. See Section 6.5 for more information on inductor current ratings.
See the following sections for more information on each parameter.
The inductor will see high voltages (VBST – VDD) during normal operation. Ideal inductors do not have a voltage rating and thus most manufacturers will not publish a voltage rating; however, certain inductor core materials have voltage limitations. Please contact the manufacturer and ensure that the inductor material can operate at high voltages.