component
LP3981-18B5F
Public Made by Adomby adom
LOWPOWER Voltage Regulators - Linear, Low Drop Out (LDO) Regulators, 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
markdownLP3981-18B5F
LOWPOWER · Voltage Regulators - Linear, Low Drop Out (LDO) Regulators · SOT-23-5
LP3981-18B5F from LOWPOWER, 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 | VIN | power_in | Power input voltage; recommended supply range is 2.5V to 5.5V, with a 6V absolute maximum. |
| 2 | GND | power_in | Ground reference pin for the regulator. |
| 3 | EN | input | Active-high chip enable with 0V to 5.5V input range; the LDO turns on above 1.2V and shuts down below 0.4V, and the pin is high impedance so a 100kΩ pull-down to GND is needed when the control signal floats. |
| 4 | NC | unconnected | No internal connection. |
| 5 | VOUT | power_out | Regulated output voltage; a ceramic output capacitor of at least 1µF with ESR greater than 25mΩ is required for stability and should be placed not more than 0.5 inch from the VOUT pin. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | LOWPOWER |
| 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 |
|---|---|---|---|---|---|---|---|
| Output Voltage Accuracy | ΔVOUT | -2 | 2 | % | IOUT = 1mA | 3 | |
| Load Regulation | ΔVLOAD | 2 | % | 1mA < IOUT < 300mA | 3 | ||
| Line Regulation | ΔVLINE | 0.3 | % | VIN = (VOUT + 1V) to 5.5V, IOUT = 1mA | 3 | ||
| Standby Current | ISTBY | 0.01 | 1 | μA | VEN = GND, Shutdown | 3 | |
| EN Input Bias Current | IIBSD | 0.01 | 100 | nA | VEN = GND or VIN | 3 | |
| Current Limit | ILIM | 360 | 400 | mA | RLOAD = 1Ω | 3 | |
| Quiescent Current | IQ | 45 | 120 | μA | VEN ≥ 1.2V, IOUT = 0mA | 3 | |
| Maximum output Current | Imax | 300 | mA | VEN=VIN, VIN>2.5V | 3 | ||
| EN Logic-Low Voltage (Shutdown) | VIL | 0.4 | V | VIN=3V to 5.5V, Shutdown | 3 | ||
| EN Logic-High Voltage (Start-Up) | VIH | 1.2 | V | VIN=3V to 5.5V, Start-Up | 3 | ||
| Output Noise Voltage | 100 | uVRMS | 10Hz to 100kHz, IOUT=200mA COUT=1µF | 3 | |||
| Absolute Maximum Supply Input Voltage | 6 | V | 3 | ||||
| Power Dissipation (SOT-25) | PD | 400 | mW | TA = 25°C, SOT-25 package | 3 | ||
| Lead Temperature (Soldering) | 260 | °C | Soldering, 10 sec. | 3 | |||
| Storage Temperature Range | -65 | 150 | °C | 3 | |||
| ESD Susceptibility HBM | 2 | kV | Human Body Model | 3 | |||
| ESD Susceptibility MM | 200 | V | Machine Model | 3 | |||
| Supply Input Voltage (recommended) | 2.5 | 5.5 | V | 3 | |||
| EN Input Voltage | 0 | 5.5 | V | 3 | |||
| Operation Junction Temperature Range | -40 | 125 | °C | 3 | |||
| Operation Ambient Temperature Range | -40 | 85 | °C | 3 | |||
| Power Supply Rejection Rate at 100Hz | PSRR | -76 | dB | f=100Hz, COUT=1µF, IOUT=50mA | 3 | ||
| Power Supply Rejection Rate at 10kHz | PSRR | -73 | dB | f=10kHz, COUT=1µF, IOUT=50mA | 3 | ||
| Thermal Shutdown Temperature | TSD | 150 | °C | 3 | |||
| Package Thermal Resistance (SOT-25) | θJA | 250 | °C/W | SOT-25 package | 3 |
CAD (KiCad official)
- Symbol:
LP3981-18B5F - Footprint:
Package_TO_SOT_SMD:SOT-23-5 - 3D model: SOT-23-5 (KiCad packages3D, STEP)
- 3D model files:
lp3981-18b5f-etched.step/lp3981-18b5f-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);lp3981-18b5f.step/lp3981-18b5f.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: LOWPOWER datasheet (6 pp, sha256
bf3050f50c362057, retrieved 2026-10-19, 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).