FDV301N - 25V 220mA N-Channel Digital FET | onsemi | SOT-23
MPN: FDV301N β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.28 | $0.28 |
| 10 | $0.22 | $2.20 |
| 100 | $0.15 | $15.00 |
| 500 | $0.11 | $55.00 |
| 1,000 | $0.09 | $90.00 |
| 3,000 | $0.08 | $240.00 |
FDV301N Overview
A digital FET, or logic-level MOSFET, is a small-signal field-effect transistor designed to switch fully on at the low gate-source voltages produced by microcontrollers, logic gates, and other digital ICs. Within the semiconductor hierarchy it sits under N-channel MOSFET -> small-signal MOSFET -> discrete power transistor -> Discrete & Power Modules. Unlike a bipolar digital transistor (which contains built-in base bias resistors), a digital FET requires no bias resistors at all, so a single device can replace several digital transistors that would otherwise need different bias-resistor values.
Key differentiating features include a 25 V drain-source rating for low-voltage rail switching, a typical RDS(on) of 4 ohm that minimizes conduction losses, and onsemi's proprietary high-cell-density DMOS silicon process. The DMOS process is specifically tailored to minimize on-state resistance at low gate drive, which is the defining characteristic of the digital-FET class.
Technically, the FDV301N is an enhancement-mode device: the channel is off at VGS = 0 V and turns on as gate voltage rises toward 2.7 V and beyond, where the datasheet characterizes RDS(on) around 5 ohm. Because the gate is insulated (MOS structure), gate drive current is negligible in steady state, allowing direct connection to GPIO pins with only a small series resistor for ESD/ring control.
Typical applications include low-side load switching in portable and battery-powered equipment, GPIO fan and LED load control, level-agnostic logic interfacing where digital transistors previously dominated, and small relay or buzzer drivers in consumer and industrial boards.
A key design consideration is power budget: at 220 mA and 4 ohm, conduction loss is roughly 0.19 W, which is Estimated: (I^2 x RDS(on), inputs 0.22 A and 4 ohm) approaching half of the 350 mW package limit, so verify worst-case VGS drive and ambient temperature.
This page synthesizes verified distributor data, drop-in alternatives, and design notes not consolidated in the manufacturer datasheet alone. Pricing shown is representative as of 2026-09-14 and should be confirmed at checkout.
Drop-in alternatives for FDV301N β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with FDV301N (same form factor and footprint) β differing in Package, Technology, Transistor Type.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
2N7002LT1G
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$0.02 / Unit
View Datasheet βFDV301N-ES
β Drop-Inπ Reference alternative (not in catalog)
MMBF170LT1G
β Drop-In β οΈ εζ°εΎ ιͺθ―π Reference alternative (not in catalog)
BSS138LT1G
β Drop-In β οΈ εζ°εΎ ιͺθ―β In Stock
$0.08 / Unit
View Datasheet βVB1240
β Drop-Inπ Reference alternative (not in catalog)
FDV301N Maximum Ratings & Electrical Characteristics
| Transistor Type | N-Channel Enhancement Mode MOSFET (Digital FET) |
| Drain-Source Voltage (Vdss) | 25 V |
| Continuous Drain Current (Id) | 220 mA (Ta) |
| Peak Drain Current | 0.5 A |
| RDS(on) at VGS = 2.7 V | 5 ohm (typical) |
| RDS(on) typical | 4 ohm |
| Power Dissipation (Pd) | 350 mW (Ta) |
| Technology | High cell density DMOS |
| Gate Drive Type | Logic level (no bias resistors required) |
| Mounting Type | Surface Mount |
| Package | SOT-23-3 |
FDV301N Pin Configuration
| Pin 1 | G (Gate) β Gate terminal - logic-level control input |
| Pin 2 | S (Source) β Source terminal - typically connected to ground in low-side switching |
| Pin 3 | D (Drain) β Drain terminal - connects to the switched load |
Safe Operating Area (SOT-23, 350 mW limit)
Typical Applications
FDV301N is suitable for 6 applications: Low-Side Load Switching in Battery-Powered Devices, GPIO LED and Indicator Driving, Small Relay and Buzzer Driver, Logic-Level Interfacing and Digital Transistor Replacement, Industrial Control Board Auxiliary Switching, Fan and Peripheral Power Gating in Embedded Systems.
Low-Side Load Switching in Battery-Powered Devices
The FDV301N fits portable battery-powered equipment because its logic-level gate turns fully on from a 2.5 V to 3.3 V microcontroller GPIO with no external bias resistors, and its DMOS process delivers about 4 ohm typical RDS(on) to keep conduction losses low on 25 V-max rails. In a typical low-side switch, the load sits between VBAT and the drain (pin 3), source (pin 2) ties to ground, and the GPIO drives gate (pin 1) through a 100 ohm series resistor. Because gate current is essentially zero in steady state, the switch adds nothing to quiescent budget; a pulldown resistor of 100k ohm prevents floating-gate leakage turn-on during MCU reset.
Recommended
GPIO LED and Indicator Driving
LED strings and indicator lamps are classic FDV301N loads: the 0.22 A continuous rating comfortably covers single high-brightness LEDs and small indicator chains, while the 4 ohm typical on-resistance wastes only milliwatts. Place the FDV301N as a low-side switch with the LED string and its current-limiting resistor between the supply rail and the drain. Unlike a digital transistor with built-in base resistors, no input-side divider is needed, so one FDV301N replaces several bias-resistor variants - the exact substitution scenario described in the onsemi datasheet. At 100 mA and 5 ohm, Estimated: dissipation is just 0.05 W (inputs I = 0.1 A, R = 5 ohm), leaving large thermal margin in the 350 mW SOT-23.
Recommended
Small Relay and Buzzer Driver
The FDV301N drives small 12 V relay coils and piezo/electromagnetic buzzers directly from 3.3 V or 5 V logic. Coil currents of 30-200 mA fall within the 0.22 A continuous rating, and the 25 V drain rating handles the nominal coil supply with margin for a clamped flyback transient. A flyback diode across the coil is mandatory - without it, the inductive turn-off spike can exceed the 25 V drain-source rating and destroy the FET. Wire the coil between the 12 V rail and the drain, source to ground, and gate to the MCU pin with a 100k ohm pulldown. The FDV301N-ES variant (0.9 A) suits higher-current relays where the base part is marginal.
Recommended
Logic-Level Interfacing and Digital Transistor Replacement
onsemi designed the FDV301N explicitly as a replacement for digital (bias-resistor) transistors in low-voltage applications: since no bias resistors are required, one N-channel FET replaces several digital transistor types that each needed different resistor values. This simplifies BOM consolidation and second-sourcing on boards with mixed 2.5 V, 3.3 V, and 5 V logic. In level-shifting roles it can pull a node low against a pullup to a different rail, forming a bidirectional open-drain translator. RDS(on) of 4-5 ohm keeps the pulled node within millivolts of ground at logic currents, and the SOT-23 footprint matches standard digital-transistor land patterns for minimal layout change.
Recommended
Industrial Control Board Auxiliary Switching
On industrial control boards the FDV301N serves as an auxiliary low-side switch for status LEDs, small buzzers, sensor supply gating, and firmware-controlled power islands. Its 25 V rating covers common 12 V and 24 V-derated auxiliaries (24 V is at the limit - verify margin), and surface-mount SOT-23 packaging fits dense controller layouts. When gating a sensor supply, note the switch drops I x RDS(on) (about 1.1 V at 220 mA worst case with 5 ohm), so budget the rail accordingly or use the part only for loads under about 100 mA where the drop is under 0.5 V. Estimated: at 100 mA the loss is 0.05 W (inputs I = 0.1 A, R = 5 ohm).
Recommended
Fan and Peripheral Power Gating in Embedded Systems
Embedded boards frequently gate small 5 V fans, buzzers, camera modules, and wireless modules under firmware control; the FDV301N performs this role up to 220 mA continuous and 0.5 A peaks (fan start-up current), turning on cleanly from a 3.3 V GPIO. Place the FET in the low-side return path with a 100k ohm gate pulldown so the peripheral stays off during processor reset or bootloader gaps. Because the on-resistance is only 4-5 ohm, the peripheral sees nearly full rail voltage - at 150 mA fan load the drop is about 0.75 V worst case (Estimated: inputs I = 0.15 A, R = 5 ohm). For loads beyond 0.5 A peak, step up to a power-stage FET instead.
Recommended
Recommended Products Summary
Engineering reference data for FDV301N β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | 2N7002LT1G | FDV301N-ES | MMBF170LT1G | BSS138LT1G | VB1240 |
|---|---|---|---|---|---|---|
| Package | SOT-23-3 | SOT-23-3 - same | SOT-23 - same | SOT-23-3 - same | SOT-23-3 - same | SOT23-3 - same |
| Brand | onsemi | onsemi | onsemi (Fairchild legacy) | onsemi | onsemi | VBsemi |
| Logic-Level Gate Drive | Yes (optimized at 2.7 V) | Yes | Yes | Yes | Yes | Yes |
Key Differentiators
- Optimized for lowest-voltage logic-level drive (vs 2N7002LT1G)
- Bias-resistor-free digital transistor replacement (vs VB1240)
- Family upgrade path in the same footprint (vs FDV301N-ES)
Design Notes
Budget conduction loss before committing to the FDV301N. Estimated: at full 220 mA load with worst-case 5 ohm RDS(on), dissipation is about 0.24 W (inputs I = 0.22 A, R = 5 ohm), roughly 70 percent of the 350 mW rating at 25 C ambient. Below about 100 mA the part is comfortable in any layout; above 150 mA, verify junction temperature with the datasheet RthJA and your board copper, and consider the 0.9 A FDV301N-ES variant for margin.
Keep the gate trace short and add a 100 ohm series resistor at the GPIO to damp ringing from long traces, plus a 100k ohm gate-to-source pulldown so the FET cannot float on during MCU reset or bootloader gaps. Because SOT-23 thermal performance depends on pad copper, extend the drain and source pads with at least a few square millimeters of pour when switching loads near 200 mA - small-signal packages rely entirely on their lands for heat removal.
The 25 V drain rating is absolute: inductive loads (relays, buzzers, fan windings) produce turn-off spikes far above the supply rail, so always fit a flyback diode across the coil or clamp the drain. Do not substitute a 20 V or lower part on 24 V rails, and do not assume 2.5 V drive achieves the 4 ohm typical RDS(on) - the datasheet characterizes 5 ohm at 2.7 V, so use that figure for worst-case loss calculations on 3.3 V logic.
Compliance Information
Compliance attributes were not captured in the retrieved distributor snippets. onsemi current-production small-signal MOSFETs are typically RoHS/lead-free, but verify per exact ordering suffix on the onsemi product page or DigiKey environmental attributes before qualification.
