The part — Series M X5R MLCC at 01005
The JMK042BJ473KC-W is a 0.047 µF ±10% X5R multilayer ceramic capacitor in the 01005 (0402 metric) surface-mount package, rated 6.3 V, from Taiyo Yuden's Series M line. At 0.40 mm × 0.20 mm with a maximum thickness of 0.22 mm, it sits at the ultra-miniature end of the MLCC range — the pad geometry and paste volume matter far more here than they would on a 0603 or 0402. X5R means the capacitance drifts with temperature: the rating is valid from -55 °C up to 85 °C, and the dielectric holds across that window without the strict frequency-stability demands that a C0G or NP0 part would impose. 6.3 V is the working voltage — for any rail running above roughly 3–4 V, derating practice pushes designers toward a 10 V or 16 V part instead, since the 6.3 V margin becomes thin in noisy SMPS environments.
SMPS filtering fit and deployment reality
SMPS filtering is the listed application, and at 47 nF this part works as a local bypass or switching-loop decoupling cap on a low-current rail — not as the bulk reservoir. The X5R temperature coefficient is acceptable in a closed chassis where ambient stays within the rated window; it would not be the right choice near a heat source that pushes local temperature above 85 °C. The ±10% tolerance covers the majority of SMPS decoupling requirements where absolute capacitance accuracy is not the primary concern. Tape & Reel and Cut Tape options give you assembly-method flexibility — reel for high-volume SMT placement, cut tape for prototypes or low-quantity runs where you want individual parts without a full reel.