TL431 regulating "5V" USB supply 4.75-5.5V range to limit under 5.032 V, simulated in circuitjs

circuit-20250129-2056.svg

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dominant-baseline="alphabetic">10k</text><path fill="none" stroke="#01fd01" paint-order="fill stroke markers" d=" M 720 496 L 784 496" stroke-linecap="round" stroke-miterlimit="10" stroke-width="3" stroke-dasharray=""/><text fill="#ffffff" stroke="none" font-family="sans-serif" font-size="12px" font-style="normal" font-weight="normal" text-decoration="normal" x="752" y="490" text-anchor="start" dominant-baseline="alphabetic"></text><path fill="none" stroke="#01fd01" paint-order="fill stroke markers" d=" M 720 496 L 704 496" stroke-linecap="round" stroke-miterlimit="10" stroke-width="3" stroke-dasharray=""/><path fill="none" stroke="#01fd01" paint-order="fill stroke markers" d=" M 672 496 L 656 496" stroke-linecap="round" stroke-miterlimit="10" stroke-width="3" stroke-dasharray=""/><g transform="matrix(-1,0,0,-1,704,496)"><path fill="none" stroke="url(#mZOCOsEkoeSS)" paint-order="fill stroke markers" d=" M 0 0 L 2 6 L 6 -6 L 10 6 L 14 -6 L 18 6 L 22 -6 L 26 6 L 30 -6 L 32 0" stroke-linecap="round" stroke-miterlimit="10" stroke-width="3" stroke-dasharray=""/></g><text fill="#ffffff" stroke="none" font-family="sans-serif" font-size="12px" font-style="normal" font-weight="normal" text-decoration="normal" x="681" y="486" text-anchor="start" dominant-baseline="alphabetic">10</text><g><g><text fill="#00ffff" stroke="none" font-family="sans-serif" font-size="14px" font-style="normal" font-weight="bold" text-decoration="normal" x="880" y="496" text-anchor="middle" dominant-baseline="central">5031.568 mV</text></g><path fill="none" stroke="#00ffff" paint-order="fill stroke markers" d=" M 832 496 L 828 496" stroke-linecap="round" stroke-miterlimit="10" stroke-width="3" stroke-dasharray=""/><path fill="#ffffff" stroke="none" paint-order="stroke fill markers" d=" M 835 496 A 3 3 0 1 1 834.9999999999577 495.99998407846124 Z"/></g><g transform="scale(1,1) translate(538,366)"><g transform="translate(102,50)" clip-path="url(#GTyvZnamnUrR)"><g><path fill="none" stroke="#A0A0A0" paint-order="fill stroke markers" d=" M 0 43 L 95 43" stroke-linecap="round" stroke-miterlimit="10" stroke-dasharray=""/><path fill="none" stroke="#404040" paint-order="fill stroke markers" d=" M 0 23 L 95 23" stroke-linecap="round" stroke-miterlimit="10" stroke-dasharray=""/><path fill="none" stroke="#404040" paint-order="fill stroke markers" d=" M 0 2 L 95 2" stroke-linecap="round" stroke-miterlimit="10" stroke-dasharray=""/><path fill="none" stroke="#404040" paint-order="fill stroke markers" d=" M 91 0 L 91 47" stroke-linecap="round" stroke-miterlimit="10" stroke-dasharray=""/><path fill="none" stroke="#404040" paint-order="fill stroke markers" d=" M 60 0 L 60 47" stroke-linecap="round" stroke-miterlimit="10" stroke-dasharray=""/><path fill="none" stroke="#404040" paint-order="fill stroke markers" d=" M 29 0 L 29 47" stroke-linecap="round" stroke-miterlimit="10" stroke-dasharray=""/><path fill="none" stroke="#FFFFFF" paint-order="fill stroke markers" d=" M 0 21 L 95 21" stroke-linecap="round" stroke-miterlimit="10" stroke-dasharray=""/><text fill="#ffffff" stroke="none" font-family="sans-serif" font-size="12px" font-style="normal" font-weight="normal" text-decoration="normal" x="0" y="10" text-anchor="start" dominant-baseline="alphabetic">Max=21.943 mW</text></g></g></g><path fill="none" stroke="#807f7f" paint-order="fill stroke markers" d=" M 656 624 L 656 564" stroke-linecap="round" stroke-miterlimit="10" stroke-width="3" stroke-dasharray=""/><path fill="none" stroke="#01fd01" paint-order="fill stroke markers" d=" M 656 556 L 656 496" stroke-linecap="round" stroke-miterlimit="10" stroke-width="3" stroke-dasharray=""/><path fill="none" stroke="#807f7f" paint-order="fill stroke markers" d=" M 646 564 L 666 564" stroke-linecap="round" stroke-miterlimit="10" stroke-width="3" stroke-dasharray=""/><path fill="none" stroke="#01fd01" paint-order="fill stroke markers" d=" M 640 556 L 672 556" stroke-linecap="round" stroke-miterlimit="10" stroke-width="3" stroke-dasharray=""/><g><g><text fill="#ffffff" stroke="none" font-family="sans-serif" font-size="14px" font-style="normal" font-weight="normal" text-decoration="normal" x="608" y="496" text-anchor="middle" dominant-baseline="central">5500.000 mV</text></g><path fill="none" stroke="#01fd01" paint-order="fill stroke markers" d=" M 656 496 L 659 496" stroke-linecap="round" stroke-miterlimit="10" stroke-width="3" stroke-dasharray=""/></g><path fill="none" stroke="#807f7f" paint-order="fill stroke markers" d=" M 832 624 L 832 564" stroke-linecap="round" stroke-miterlimit="10" stroke-width="3" stroke-dasharray=""/><path fill="none" stroke="#807f7f" paint-order="fill stroke markers" d=" M 820 564 L 844 564" stroke-linecap="round" stroke-miterlimit="10" stroke-width="3" stroke-dasharray=""/><path fill="none" stroke="#01fd01" paint-order="fill stroke markers" d=" M 832 496 L 832 556" stroke-linecap="round" stroke-miterlimit="10" stroke-width="3" stroke-dasharray=""/><path fill="none" 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paint-order="fill stroke markers" d=" M 0 33 L 191 33" stroke-linecap="round" stroke-miterlimit="10" stroke-dasharray=""/><path fill="none" stroke="#404040" paint-order="fill stroke markers" d=" M 0 7 L 191 7" stroke-linecap="round" stroke-miterlimit="10" stroke-dasharray=""/><path fill="none" stroke="#404040" paint-order="fill stroke markers" d=" M 187 0 L 187 143" stroke-linecap="round" stroke-miterlimit="10" stroke-dasharray=""/><path fill="none" stroke="#404040" paint-order="fill stroke markers" d=" M 156 0 L 156 143" stroke-linecap="round" stroke-miterlimit="10" stroke-dasharray=""/><path fill="none" stroke="#404040" paint-order="fill stroke markers" d=" M 125 0 L 125 143" stroke-linecap="round" stroke-miterlimit="10" stroke-dasharray=""/><path fill="none" stroke="#404040" paint-order="fill stroke markers" d=" M 94 0 L 94 143" stroke-linecap="round" stroke-miterlimit="10" stroke-dasharray=""/><path fill="none" stroke="#404040" paint-order="fill stroke markers" d=" M 62 0 L 62 143" stroke-linecap="round" stroke-miterlimit="10" stroke-dasharray=""/><path fill="none" stroke="#404040" paint-order="fill stroke markers" d=" M 31 0 L 31 143" stroke-linecap="round" stroke-miterlimit="10" stroke-dasharray=""/><path fill="none" stroke="#404040" paint-order="fill stroke markers" d=" M 0 0 L 0 143" stroke-linecap="round" stroke-miterlimit="10" stroke-dasharray=""/><path fill="none" stroke="#00ff00" paint-order="fill stroke markers" d=" M 0 71 L 191 71" stroke-linecap="round" stroke-miterlimit="10" stroke-dasharray=""/><text fill="#ffffff" stroke="none" font-family="sans-serif" font-size="12px" font-style="normal" font-weight="normal" text-decoration="normal" x="0" y="10" text-anchor="start" dominant-baseline="alphabetic">Max=5.032 V</text><text fill="#ffffff" stroke="none" font-family="sans-serif" font-size="12px" font-style="normal" font-weight="normal" text-decoration="normal" x="0" y="139" text-anchor="start" dominant-baseline="alphabetic">Min=5.032 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sim

When divided in 2, the range becomes 2.373-2.516V, which lies within the iCE40 LP/HX LVCMOS25 recommended range of 2.37-2.62V.

When divided again in 2, the range becomes 1.186-1.258V, which lies within the iCE40 LP/HX core's recommended range of 1.14-1.26V.

If put a 1kohm potentiometer in the middle of the divider, then the resistors of the divider could be off by 5% and still could get a 5.035V regulated voltage: