8th-Order Bessel Low-Pass — 5 kHz cutoff, single 5V rail
The MAX7401ESA+ is an 8th-order Bessel low-pass switched-capacitor filter from Analog Devices, with a cutoff frequency of 5 kHz. The Bessel characteristic preserves the phase linearity of the passband — the group delay is flat to within the filter order's approximation, so a pulse train through the filter keeps its shape without overshoot or ringing on the edges. The 8th-order roll-off is steep — roughly 48 dB/octave — so it cleanly separates a 5 kHz baseband from switching noise or out-of-band harmonics without needing a multi-stage discrete filter.
Package and board-fit — 8-SOIC, tube delivery
The supply pins are on opposite corners (pin 8 for VDD, pin 4 for GND) — a 0.1 µF ceramic decoupling cap placed between them, as close to the pins as the layout allows, keeps the switched-capacitor clock noise off the supply plane. Shipped in tube format — not tape-and-reel — so for a pick-and-place line the tube must be loaded into a vibratory feeder or the parts re-taped. This matters for high-volume insertion; a reeled variant (the MAX7401ESA+T) exists if the line is set up for tape-only.
Compliance and lifecycle — active, ROHS3, no EOL watch
ROHS3 compliance covers the full substance restriction list (including the four phthalates). No REACH or UL documentation is cited in the standard listing; the factory datasheet is the authoritative source for material declarations.