WS2812B-2020 is a complete addressable pixel, not a bare LED: the constant-current controller and the three RGB dies share one 2.20 × 2.00 mm 2020 package and one supply pin.^p.1 Four pads — DI in, DO out, VDD, GND^p.2 — and data is the only design work: a single-line NZR stream at 800 Kbps, 24 bits per pixel in GRB order, high bit first.^{p.1, p.4} Each pixel latches its first 24 bits, then reshapes and re-drives the rest downstream, so distortion does not accumulate and cascade length is limited only by data rate — ≥1024 pixels at 30 fps, up to 3 m between any two points with no extra circuitry.^p.1

The numbers you design against: each channel is driven at a constant 16 mA,^{p.1, p.3} returning 300–500 mcd red, 800–1500 mcd green and 200–300 mcd blue.^p.3 Bit timing is T0H 220–380 ns / T1H 580 ns–1 µs, and the reset frame is a generous >280 µs low — long enough that an interrupted MCU will not false-reset the string.^{p.1, p.3} Refresh is scanned at 2 kHz, so it holds up on HD video.^p.1 The typical application circuit wants a 100 nF filter capacitor on VDD at the pixel.^p.4

Two limits are tighter than instinct suggests. Supply: the absolute-maximum rating is +3.7 to +5.3 V — this is a 5 V part with less headroom than a plain LED, and logic thresholds track the rail (V_IH = 0.7 V_DD), which matters when driving it from 3.3 V logic.^{p.2, p.3} Moisture: it is rated MSL 6, the most sensitive class — solder it immediately after opening the bag, and re-bake before any second reflow.^p.7 Junction temperature is bounded at −25 to +85 °C.^p.2