Part A
AO3401
Alpha Omega Semiconductor GmbH.
- Lifecycle
- Active
- Stock
- 6918 PCS
- Package
- SOT-23
- Series
- Transistors - FET, MOSFET - simples
Replacement verdict
Compatible functional replacement candidate
The AO3401A is a direct functional replacement candidate for the AO3401, sharing the same P-channel MOSFET topology, SOT-23 package, and pinout. Designers should validate the tighter gate threshold and slightly reduced drain current margin against their specific circuit conditions before substituting in volume production.
Channel Polarity and Type
High match
Package and Pinout
High match
Drain Current Rating
Validation required
Gate Threshold Voltage
Validation required
Parts at a glance
Part B
AO3401A
Alpha Omega Semiconductor GmbH.
- Lifecycle
- Active
- Stock
- 3989 PCS
- Package
- SOT-23
- Series
- Transistors - FET, MOSFET - simples
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AO3401A | AO3401 | Why it matters |
|---|---|---|---|
| Drain-Source Voltage (Vds) | -30 V | -30 V | Maximum voltage the device can block; must exceed the rail voltage in the target circuit. |
| Continuous Drain Current (Id) | -4.0 A | -4.0 A | Determines the load current the FET can carry continuously without overheating. |
| On-Resistance Rds(on) at Vgs = -10 V | 50 mΩ (max) | 60 mΩ (max) | Lower Rds(on) reduces conduction losses and heat; a key indicator of efficiency and substitutability. |
| On-Resistance Rds(on) at Vgs = -4.5 V | 60 mΩ (max) | 75 mΩ (max) | Relevant for low-voltage gate drive circuits; affects performance when driven below 10 V. |
| Gate Threshold Voltage (Vgs(th)) | -1.3 V (max) | -1.3 V (max) | Defines the gate voltage at which the FET begins to conduct; critical for logic-level compatibility. |
| Total Gate Charge (Qg) | 4.3 nC (typ) | 4.3 nC (typ) | Affects switching speed and gate drive power; lower Qg enables faster, more efficient switching. |
| Power Dissipation (Pd) | 1.4 W | 1.4 W | Maximum power the package can dissipate; sets thermal limits for the application. |
| Package | SOT-23 | SOT-23 | Footprint and thermal characteristics must match for a drop-in replacement. |
| Channel Type | P-Channel | P-Channel | Channel polarity must match the circuit topology (high-side switching, reverse polarity protection, etc.). |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AO3401 | AO3401A |
|---|---|---|
| Part Status | Not For New Designs | Not For New Designs |
| FET Type | P-Channel | P-Channel |
| Technology | MOSFET (Metal Oxide) | MOSFET (Metal Oxide) |
| Drain to Source Voltage (Vdss) | 30 V | 30 V |
| Current - Continuous Drain(Id) @ 25°C | 4A (Ta) | 4A (Ta) |
| Drive Voltage(Max Rds On Min Rds On) | 2.5V, 10V | 2.5V, 10V |
| Rds On(Max) @ Id Vgs | 50mOhm @ 4A, 10V | 44mOhm @ 4.3A, 10V |
| Vgs(th)(Max) @ Id | 1.3V @ 250µA | 1.3V @ 250µA |
| Gate Charge(Qg)(Max) @ Vgs | 14 nC @ 10 V | 12.2 nC @ 4.5 V |
| Vgs(Max) | ±12V | ±12V |
| Input Capacitance(Ciss)(Max) @ Vds | 645 pF @ 15 V | 1200 pF @ 15 V |
| Power Dissipation (Max) | 1.4W (Ta) | 1.4W (Ta) |
| Operating Temperature | -55°C ~ 150°C (TJ) | -55°C ~ 150°C (TJ) |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What is the difference between AO3401A and AO3401?
Both are P-channel enhancement-mode MOSFETs in SOT-23 packages from Alpha & Omega Semiconductor. The AO3401A is a revised version of the AO3401. The primary difference is in the gate threshold voltage (VGS(th)) specification and the guaranteed RDS(on) at VGS = -2.5 V. The AO3401A specifies a maximum VGS(th) of -1.3 V, while the AO3401 specifies a maximum VGS(th) of -1.4 V. Designers should consult the respective datasheets for the exact limits relevant to their operating conditions.
Are AO3401A and AO3401 pin-compatible?
Yes. Both devices use the standard SOT-23 (TO-236) package with the same pinout: Pin 1 = Gate, Pin 2 = Source, Pin 3 = Drain. The package dimensions and PCB land pattern are identical, so they are drop-in compatible from a mechanical and pinout perspective.
What are the key ratings of the AO3401A and AO3401?
Both devices are rated for a drain-source voltage (VDS) of -30 V, a continuous drain current (ID) of -4 A at TC = 25 °C, and a maximum power dissipation (PD) of 1.4 W at TA = 25 °C. Both feature low on-resistance, with RDS(on) specified at VGS = -10 V and VGS = -4.5 V. Refer to the manufacturer datasheets for the exact RDS(on) values and test conditions.
Can AO3401A be used as a direct replacement for AO3401?
In most designs, yes, because the two parts share the same package, pinout, VDS rating, and current rating. However, the AO3401A has a tighter gate threshold voltage specification, which can affect circuits that rely on a specific VGS(th) window. Verify the VGS(th) and RDS(on) limits in the target design before substituting.
What is the gate threshold voltage of AO3401A versus AO3401?
The AO3401A specifies a gate threshold voltage range of -0.5 V to -1.3 V (VDS = VGS, ID = -250 µA). The AO3401 specifies a range of -0.5 V to -1.4 V under the same test conditions. The AO3401A therefore offers a slightly tighter upper limit on VGS(th).
Are both AO3401A and AO3401 RoHS compliant?
Yes. Both the AO3401A and AO3401 are offered in RoHS-compliant, halogen-free packages per Alpha & Omega Semiconductor's environmental documentation. Confirm the specific ordering suffix and packaging option on the manufacturer datasheet for the exact compliance statement applicable to the purchased part number.
What applications are AO3401A and AO3401 suitable for?
Both P-channel MOSFETs are intended for load switching, battery protection, power management, and level-shifting in portable and consumer electronics. Their -30 V VDS rating and low RDS(on) make them suitable for low-voltage, high-side switching applications where a small SOT-23 footprint is required.