IRLML6401TRPBF - -12V P-Ch 4.3A HEXFET MOSFET | Infineon
MPN: IRLML6401TRPBF ⚠ Last Time Buy| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $0.41 | $0.41 |
| 10 | $0.36 | $3.60 |
| 100 | $0.24 | $24.00 |
| 500 | $0.18 | $90.00 |
| 1,000 | $0.14 | $140.00 |
IRLML6401TRPBF Overview
A P-Channel MOSFET is a majority-carrier field-effect transistor in which the conducting channel is formed by holes rather than electrons. P-Channel devices simplify high-side switching because the source sits at the load supply rail and the MOSFET is turned on by pulling the gate below the source, eliminating the need for a charge pump or bootstrap circuit. P-Channel MOSFETs belong to the power MOSFET family within the broader discrete semiconductor category and are widely used for low-voltage load management, battery protection, and reverse-polarity protection.
The IRLML6401TRPBF key feature set includes: -12 V VDS, -4.3 A continuous ID at TA = 25 C, 50 mOhm maximum RDS(on) at VGS = -4.5 V, logic-level VGS(th) of typically -0.7 V to -1.5 V, 1.3 W power dissipation at TA = 25 C, fast switching, and ruggedized HEXFET construction. The extremely low on-resistance per silicon area gives high efficiency in small-outline designs where PCB copper is limited.
Internally the device uses Infineon's advanced planar HEXFET process technology, which combines a vertical DMOS structure with a P-Channel body region to achieve low figure-of-merit RDS(on) x Qg. The SOT-23 footprint is industry-standard 3-lead with the drain, source and gate assignments on pins 1, 2, 3 respectively, allowing pin-compatible drop-in substitution by several competitors. The exposed lead frame aids thermal conduction to PCB copper.
Typical applications include: load switching in portable electronics, battery management and protection, USB power rail control, power-ORing and reverse-polarity protection, DC-DC converter high-side switches, and LED backlight drivers. The logic-level gate drive is the key enabler for direct microcontroller I/O control in 1.8 V / 3.3 V systems.
When designing with this device, ensure that peak drain current stays below the SOA curve and that total gate charge is sourced within the driver's capability. Always confirm VGS drive polarity: this part requires negative VGS to turn on, which differs from N-Channel parts - this is the most common design pitfall.
This page synthesizes Infineon datasheet specifications, parametric comparison with pin-compatible P-Channel SOT-23 MOSFETs from competing vendors, and practical design notes that go beyond the data sheet's typical application section.
Drop-in alternatives for IRLML6401TRPBF — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
IRLML6402TRPBF
✅ Drop-In📋 Reference alternative (not in catalog)
IRLML6401TRPBF-1
✅ Drop-In📋 Reference alternative (not in catalog)
AO3401A
✅ Drop-In📋 Reference alternative (not in catalog)
DMG2305UX-7
✅ Drop-In📋 Reference alternative (not in catalog)
Si2301BDS-T1-E3
✅ Drop-In📋 Reference alternative (not in catalog)
AO3407A
✅ Drop-In📋 Reference alternative (not in catalog)
IRLML6401TRPBF Maximum Ratings & Electrical Characteristics
| FET Type | P-Channel |
| Drain-to-Source Voltage (VDS) | -12 V |
| Continuous Drain Current (ID) | -4.3 A (Ta) |
| Power Dissipation (PD) | 1.3 W (Ta) |
| On-Resistance RDS(on) MAX | 50 mOhm @ VGS = -4.5 V |
| Gate Threshold Voltage VGS(th) | -0.7 V to -1.5 V (typ) |
| Total Gate Charge Qg | 10 nC (typ) |
| Technology | HEXFET (IR MOSFET) |
| Package | Micro3 / SOT-23, 3 leads |
| Mounting Type | Surface Mount |
| Operating Temperature | -55 C to +150 C (junction) |
| Lead Profile Height | < 1.1 mm |
| Gate Drive Level | Logic-level (1.8 V / 3.3 V compatible) |
| RoHS Compliance | Compliant |
| MSL Level | MSL 1 |
IRLML6401TRPBF Pin Configuration
| Pin 1 | Source (S) — P-Channel source, connects to higher-voltage rail |
| Pin 2 | Gate (G) — Logic-level gate drive; pull below source to turn on |
| Pin 3 | Drain (D) — P-Channel drain, connects to load |
Safe Operating Area (DC)
Typical Applications
IRLML6401TRPBF is suitable for 7 applications: USB Load Switch and Power Rail Control, Single-Cell Li-Ion Battery Management, Reverse-Polarity Protection, DC-DC Converter High-Side Switch, LED Backlight and Indicator Driver, Industrial Sensor and Modbus Power Switching, Power OR-ing and Redundant Supply Switching.
USB Load Switch and Power Rail Control
The IRLML6401TRPBF suits USB load-switch and power-rail control roles because its -12 V VDS comfortably covers the 5 V USB rail with a logic-level gate drive that connects directly to a microcontroller GPIO. The 50 mOhm RDS(on) at VGS = -4.5 V gives a conduction drop of only 100 mV at 2 A, preserving tight load-line regulation for downstream regulators. The SOT-23 footprint consumes less than 10 mm^2 of board area, ideal for dense consumer designs such as phone chargers and USB hubs. Compared with using a load-switch IC, this discrete P-Channel solution is cheaper and faster to turn on, at the cost of a small external pull-up resistor on the gate. Place the source at the 5 V rail and drive the gate with the open-drain GPIO to switch power to downstream ports.
Recommended
Single-Cell Li-Ion Battery Management
The IRLML6401TRPBF is well-matched to single-cell Li-Ion battery management, where it acts as a reverse-polarity and over-current protection switch. The -12 V VDS rating exceeds the 4.2 V maximum Li-ion voltage, and the 4.3 A continuous ID supports typical 2 A fast-charge currents with substantial thermal margin. RDS(on) of 50 mOhm produces roughly 0.2 W conduction loss at 2 A, manageable in the SOT-23 package on 1 square inch of copper. The logic-level gate threshold allows direct drive from a 1.8 V battery-management MCU without a charge pump. Battery-management designs should derate ID to 2.5 A at TA = 60 C and consider the AO3401A as a second source where long-term production is required.
Recommended
Reverse-Polarity Protection
The IRLML6401TRPBF delivers robust reverse-polarity protection when its source is placed at the supply rail and drain at the load, with gate tied to ground through a resistor. During a reverse-battery event the body diode blocks current until the MCU pulls the gate up, at which point the channel closes and RDS(on) of 50 mOhm limits fault current to roughly 200 mA at 12 V input - well within the 4.3 A package rating. This protection topology is preferred over a Schottky diode because the IRLML6401TRPBF dissipates an order of magnitude less heat at full load. Designers should add a TVS clamp on the source for transients beyond -12 V. The DMG2305UX-7 from Diodes Incorporated is a pin-compatible alternate for production continuity.
Recommended
DC-DC Converter High-Side Switch
In a buck or boost DC-DC converter the IRLML6401TRPBF can serve as the high-side P-Channel switch for low-voltage rails up to 12 V. The 10 nC typical total gate charge keeps switching losses low at 500 kHz, and the 50 mOhm RDS(on) supports continuous load currents around 2 A without exceeding the 1.3 W package limit. The logic-level gate drive enables direct control from a PWM output, simplifying the gate-driver stage. Compared with N-Channel high-side designs the IRLML6401TRPBF eliminates the bootstrap capacitor, reducing BOM cost and PCB area. The Vishay Si2301BDS-T1-E3 is a documented drop-in alternate where multiple sourcing options are required.
Recommended
LED Backlight and Indicator Driver
The IRLML6401TRPBF works as a logic-controlled switch for LED backlights and indicator lamps in portable displays. Its 4.3 A ID comfortably drives strings of up to 1 A with proper current-limit resistor selection, and the SOT-23 profile under 1.1 mm allows placement behind the LCD panel. The P-Channel high-side topology eliminates the need for a discrete current-limit IC when paired with an MCU PWM output. RDS(on) of 50 mOhm gives less than 5 percent brightness variation across the string voltage range. Production designs should consider the AO3401A as a long-term alternate given the IRLML6401TRPBF last-time-buy status announced by Infineon.
Recommended
Industrial Sensor and Modbus Power Switching
The IRLML6401TRPBF supports industrial 4-20 mA sensor loops and Modbus power switching where the supply is typically 24 V, but it must be derated or replaced by a higher-VDS P-Channel for direct 24 V operation. Within 12 V industrial rails it provides clean load-disconnect with logic-level gate control from a 3.3 V PLC GPIO. The HEXFET construction gives high ruggedness against inductive transients from solenoids and relays. Industrial designers should add a TVS diode on the source to clamp transients below -12 V and prefer the IRLML6402 (-20 V) for borderline-voltage applications. The part's MSL 1 rating simplifies factory handling on automated pick-and-place lines.
Recommended
Power OR-ing and Redundant Supply Switching
The IRLML6401TRPBF works in low-voltage power OR-ing applications where two supplies, such as a wall adapter and a USB input, feed a common load. Using one P-Channel MOSFET per supply with gates cross-coupled to the opposite source implements a diode-OR with one tenth the conduction loss of a Schottky solution. At 2 A load, each IRLML6401TRPBF dissipates roughly 0.2 W (P = I^2 x RDS(on)) instead of 0.7 W in a Schottky diode. The logic-level gate drive eliminates charge-pump circuitry. Designers should keep the input voltage below 12 V and use the AO3401A as a second source for volume production beyond the Infineon last-time-buy window.
Recommended
Recommended Products Summary
Engineering reference data for IRLML6401TRPBF — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | IRLML6402TRPBF | IRLML6401TRPBF-1 | AO3401A | DMG2305UX-7 | Si2301BDS-T1-E3 | AO3407A |
|---|---|---|---|---|---|---|---|
| Brand | Infineon | Infineon | Infineon | Alpha & Omega Semiconductor | Diodes Incorporated | Vishay Intertechnology | Alpha & Omega Semiconductor |
| Package | SOT-23 | SOT-23 - same | SOT-23 - same | SOT-23 - same | SOT-23 - same | SOT-23 - same | SOT-23 - same |
| FET Type | P-Channel | P-Channel | P-Channel | P-Channel | P-Channel | P-Channel | P-Channel |
| Drain-to-Source Voltage VDS | -12 V | -20 V | -12 V | -30 V | -20 V | -20 V | -30 V |
| Continuous Drain Current ID | -4.3 A | -3.7 A | -4.3 A | -4.0 A | -4.2 A | -3.5 A | -4.1 A |
| On-Resistance RDS(on) max @ VGS = -4.5 V | 50 mOhm | 65 mOhm | 50 mOhm | 60 mOhm | 52 mOhm | 55 mOhm | 60 mOhm |
| Gate Threshold VGS(th) typical | -1.0 V | -1.0 V | -1.0 V | -1.0 V | -1.2 V | -1.0 V | -1.0 V |
| Total Gate Charge Qg typical | 10 nC | 12 nC | 10 nC | 11 nC | 10 nC | 9 nC | 11 nC |
| Power Dissipation PD | 1.3 W | 1.3 W | 1.3 W | 1.4 W | 1.4 W | 1.25 W | 1.4 W |
Key Differentiators
- Lower on-resistance than the IRLML6402 variant (vs IRLML6402TRPBF)
- Wider voltage headroom than the original target (vs AO3401A)
- Smaller SOT-23 footprint with the same ID rating as SO-8 P-Channel parts (vs Si2301BDS-T1-E3)
Design Notes
Estimated: at ID = 2 A continuous, VGS = -4.5 V and RDS(on) = 50 mOhm, conduction dissipation = I^2 * R = 4 * 0.05 = 0.2 W. On a 1 square inch 2 oz copper pour the SOT-23 thermal resistance is roughly 80 C/W, giving a junction temperature rise of 16 C above 25 C ambient - well within the 150 C junction limit. Above 3 A continuous, copper area must increase to at least 2 square inches, or the load current must be reduced, to keep junction temperature below 125 C.
The IRLML6401TRPBF is a P-Channel MOSFET and requires the gate to be pulled BELOW the source voltage to turn on. The most common design pitfall is to apply a positive gate voltage (relative to source) expecting enhancement - this actually turns the device OFF. Always confirm gate-drive polarity before applying power: for a high-side switch, tie the gate to ground through a pull-down resistor and drive it to source voltage (or above) to disable, or to ground (or below source) to enable. Adding a 100 kOhm pull-down resistor to ground prevents unintended turn-on during MCU reset.
Place the IRLML6401TRPBF as close as practical to the load-side decoupling capacitor to minimise switching-current loop area and EMI. Use a wide copper pour on the source pin - this is the power-return path and also the primary thermal dissipation path. The drain and source pads should have at least 0.5 square inches of copper each. Avoid routing digital signal traces directly under the MOSFET body to prevent switching-noise coupling into sensitive analog sections.
For high-side load-switch applications, add a TVS diode or Zener clamp across the source-drain to clamp inductive transients below the -12 V VDS rating. The gate-drive trace should be kept short (under 10 mm) and routed away from switching nodes. If the gate is driven by an MCU output, add a 100 Ohm series resistor close to the gate pin to dampen ringing. Use a star-ground topology so that the source current return does not share a path with the gate-driver return.
Compliance Information
RoHS compliant per Infineon product page. Lead-free finish. MSL 1 rating. Not AEC-Q100 qualified - this part is intended for commercial and industrial environments; for automotive designs use an AEC-Q100 qualified P-Channel MOSFET in SOT-23.
