component
NCT3521U
Public Made by Adomby adom
Nuvoton Tech Power Distribution Switches, SOT-23-5. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.
3D Model
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Symbol & Footprint
Schematic Symbol
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PCB Footprint
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Datasheet
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README
markdownNCT3521U
Nuvoton Tech · Power Distribution Switches · SOT-23-5
NCT3521U from Nuvoton Tech, in a SOT-23-5. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.
Pinout
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | OUT | power_out | Output voltage pin, the N-MOSFET source that delivers the switched voltage to the load; a 0.1uF or greater ceramic capacitor should be connected from this pin to GND as close to the chip as possible. |
| 2 | GND | power_in | Ground reference pin for the device. |
| 3 | EN | input | High-active enable input; pulling this pin to logic low disables the chip, and it must not be left floating (connect to logic high or low). |
| 4 | DIS | passive | Discharge pin, the drain of an internal N-MOSFET that is active only when the chip is disabled; a resistor from DIS to OUT lets the OUT voltage be discharged through this pin. |
| 5 | IN | power_in | Input voltage pin, the N-MOSFET drain that supplies the output current and the chip's operating current; a 0.1uF or greater ceramic capacitor should be connected from this pin to GND as close to the chip as possible. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | Nuvoton Tech |
| Package | SOT-23-5 |
| Category | Power Management (PMIC) |
| Pins | 5 |
Electrical characteristics
Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).
| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| VIN Under Voltage Lockout | 1.6 | 2.3 | 2.6 | V | 8 | ||
| Output Turn-on Rising Time | 1.3 | 1.9 | 2.7 | ms | RL = 10Ω, 90 % Setting | 8 | |
| Current Limit Threshold | ILIMIT | 2.4 | 3 | 3.6 | A | VOUT = 4V | 8 |
| Output Short-circuit Current | 0.2 | 1.3 | 1.9 | A | VOUT = 0V, 2.7V < VIN < 5.5V | 8 | |
| Reverse voltage trip level | VOUT-IN | 95 | 135 | 190 | mV | 8 | |
| Time from reverse voltage condition to MOSFET turn off | 2 | 4 | 8 | ms | VIN = 5V | 8 | |
| Supply Input Voltage | VIN | 2.7 | 5.5 | V | 7 | ||
| Ambient Operating Temperature | -40 | 85 | ℃ | 7 | |||
| Junction Temperature (recommended) | -40 | 125 | ℃ | 7 | |||
| Input Supply Voltage (absolute maximum) | -0.3 | 6 | V | 7 | |||
| Other Pins | -0.3 | 6 | V | 7 | |||
| Storage Temperature | -50 | 150 | ℃ | 7 | |||
| Junction Temperature (absolute maximum) | 150 | ℃ | 7 | ||||
| ESD Human Body Model | 2 | kV | 7 | ||||
| ESD Machine Model | 200 | V | 7 | ||||
| Latch-up | 100 | mA | 7 | ||||
| Package Thermal Resistance, SOT23-5, θJA | θJA | 240 | ℃/W | SOT23-5 | 7 |
CAD (KiCad official)
- Symbol:
NCT3521U - Footprint:
Package_TO_SOT_SMD:SOT-23-5 - 3D model: SOT-23-5 (KiCad packages3D, STEP)
- 3D model files:
nct3521u-etched.step/nct3521u-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);nct3521u.step/nct3521u.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Nuvoton Tech datasheet (13 pp, sha256
c20bf8f527c307b8, retrieved 2026-10-20, tier: lcsc) - Extractor: parts-factory
2.0.0/extract_pins 0.3, primaryclaude-haiku-5-5(text), consensusclaude-sonnet-5-5(agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish. - CAD: KiCad official libraries (CC-BY-SA 4.0).