AO3401 — -30V -4.0A P-Channel Logic-Level MOSFET (SOT-23)

Overview

The AO3401 (and improved AO3401A) is a -30V -4.0A P-channel logic-level enhancement mode power MOSFET manufactured by Alpha & Omega Semiconductor. Housed in an industry-standard surface-mount SOT-23 package, it is designed using advanced trench technology to achieve ultra-low on-resistance and low gate charge.

Providing a maximum on-state resistance of just $55\text{ m}\Omega$ at $V_{GS} = -4.5\text{V}$ and fully specified down to $V_{GS} = -2.5\text{V}$ ( $85\text{ m}\Omega$ ), the AO3401 enables high-side switching directly from $3.3\text{V}$ or $5\text{V}$ microcontrollers. As the P-channel counterpart to the ubiquitous AO3400, the AO3401 is widely used in battery-powered high-side power distribution switches, USB port power gating, low-loss reverse polarity protection circuits, and DC-DC converter output disconnect stages.

Quick reference


Transistor Type	P-Channel Logic-Level Enhancement Mode MOSFET
Package	SOT-23 (3-pin SMD)
Drain-Source Breakdown Voltage ( $V_{DSS}$ )	$-30\text{ V}$ max
Gate-Source Voltage ( $V_{GSS}$ )	$\pm 12\text{ V}$ max
Continuous Drain Current ( $I_D$ )	$-4.0\text{ A}$ ( $T_A = 25^\circ\text{C}$ ) / $-3.5\text{ A}$ ( $T_A = 70^\circ\text{C}$ )
Pulsed Drain Current ( $I_{DM}$ )	$-30\text{ A}$
On-Resistance ( $R_{DS(on)}$ at $-10\text{V}$ )	$44\text{ m}\Omega$ max ( $35\text{ m}\Omega$ typ)
On-Resistance ( $R_{DS(on)}$ at $-4.5\text{V}$ )	$55\text{ m}\Omega$ max ( $43\text{ m}\Omega$ typ)
On-Resistance ( $R_{DS(on)}$ at $-2.5\text{V}$ )	$85\text{ m}\Omega$ max ( $63\text{ m}\Omega$ typ)
Gate Threshold Voltage ( $V_{GS(th)}$ )	$-0.7\text{ V}$ to $-1.3\text{ V}$ (Sub-2.5V Logic Direct Drive)
Power Dissipation ( $P_D$ )	$1.4\text{ Watts}$ ( $T_A = 25^\circ\text{C}$ )
Complementary N-Channel Pair	AO3400 / AO3400A

Pinout (SOT-23 Package)

Looking at the top of the SOT-23 package:

text

           ┌───┴───┐
           │   3   │ ── Pin 3: DRAIN (D)
           │       │
           │ AO3401│
           └──┬─┬──┘
              1 2
       Pin 1: GATE (G)
       Pin 2: SOURCE (S)

Pin	Name	Type	Description
1	`GATE (G)`	Control Input	Gate terminal (Driven LOW relative to Source to turn ON)
2	`SOURCE (S)`	Power Terminal	Source terminal (Connected to positive supply rail or battery positive)
3	`DRAIN (D)`	Power Terminal	Drain terminal (Connected to positive side of the switched load)

Specifications

Parameter	Symbol	Min	Typ	Max	Unit	Conditions
Drain-Source Breakdown	$V_{(BR)DSS}$	-30	—	—	V	$I_D = -250\ \mu\text{A}, V_{GS} = 0\text{V}$
Gate Threshold Voltage	$V_{GS(th)}$	-0.7	-0.9	-1.3	V	$V_{DS} = V_{GS}, I_D = -250\ \mu\text{A}$
Zero Gate Voltage Drain Current	$I_{DSS}$	—	—	-1.0	µA	$V_{DS} = -24\text{V}, V_{GS} = 0\text{V}$
Gate-Body Leakage Current	$I_{GSS}$	—	—	$\pm 100$	nA	$V_{GS} = \pm 12\text{V}, V_{DS} = 0\text{V}$
Static Drain-Source On-Resistance	$R_{DS(on)}$	—	35	44	mΩ	$V_{GS} = -10\text{V}, I_D = -4.0\text{A}$
Static Drain-Source On-Resistance	$R_{DS(on)}$	—	43	55	mΩ	$V_{GS} = -4.5\text{V}, I_D = -3.5\text{A}$
Static Drain-Source On-Resistance	$R_{DS(on)}$	—	63	85	mΩ	$V_{GS} = -2.5\text{V}, I_D = -2.5\text{A}$
Total Gate Charge	$Q_g$	—	11	14	nC	$V_{GS} = -10\text{V}, V_{DS} = -15\text{V}, I_D = -4.0\text{A}$

Typical Application Circuit: Ideal Diode / Reverse-Polarity Battery Protection

Using a P-channel MOSFET in place of a Schottky diode eliminates the $0.3\text{V} \dots 0.5\text{V}$ diode voltage drop, reducing power loss to milliwatts:

text

  +3.7V / +5V Power In ───────► [Pin 2: SOURCE]
                                    AO3401
  Common Ground (0V)   ───────► [Pin 1: GATE]   ───► [Pin 3: DRAIN] ───► Protected +Vout to Circuit
                                                         │
                                               [ 10µF Bypass Cap ]
                                                         │
  Common Ground (0V)   ──────────────────────────────────┴──────────────► Common Ground Return

(When power is connected with correct polarity, $V_{GS} = -V_{IN}$ , turning the channel fully ON with only $R_{DS(on)} \times I$ drop. If reverse polarity is connected, $V_{GS} > 0\text{V}$ , remaining safely OFF).

Common mistakes

Exceeding the $\pm 12\text{V}$ Gate-Source ( $V_{GSS}$ ) rating: Unlike standard power MOSFETs with $\pm 20\text{V}$ gate limits, the AO3401 has an absolute maximum $V_{GS}$ limit of $\pm 12\text{V}$ . When switching supplies above $12\text{V}$ (e.g. 24V rails), use a Zener diode (e.g. 10V) or voltage divider to limit $V_{GS}$ .
Reversing Drain and Source: Because power MOSFETs have an intrinsic body diode from Drain to Source, connecting Source to the load and Drain to $+V_{IN}$ allows current to continuously conduct through the forward-biased body diode even when the gate is turned OFF.

Notes

Top Marking Code: AO3401/AO3401A packages are commonly laser-marked with top codes A19T, AO1, or X1DV.

Interface	Sub-2.5V to 10V Gate Drive Compatible
Package	SOT-23 (3-pin SMD)