IRF9540 — -100V -23A P-Channel HEXFET Power MOSFET (TO-220)

Overview

The IRF9540 (and advanced IRF9540N) is a -100V -23A P-channel HEXFET power MOSFET manufactured by Infineon (originally International Rectifier), Vishay, and STMicroelectronics. Housed in an industry-standard TO-220AB through-hole package, it is the world's most famous through-hole high-voltage P-channel power MOSFET.

Providing a high drain-source breakdown voltage rating of $-100\text{V}$ , a continuous drain current rating of $-23\text{A}$ ( $-76\text{A}$ pulsed peak), and an on-state resistance of $117\text{ m}\Omega$ at $V_{GS} = -10\text{V}$ with $140\text{ Watts}$ of power dissipation capability ( $\theta_{JC} = 1.1^\circ\text{C/W}$ ), the IRF9540 is the undisputed P-channel companion to the iconic IRF540N. It is widely employed in complementary MOSFET Class AB audio power amplifiers, full-bridge reversible DC motor drivers, high-side power distribution switches for 24V/48V systems, and solar battery cutoff circuits.

Quick reference


Transistor Type	P-Channel HEXFET Power MOSFET
Package	TO-220AB (3-pin through-hole)
Drain-Source Breakdown Voltage ( $V_{DSS}$ )	$-100\text{ V}$ max
Gate-Source Voltage ( $V_{GSS}$ )	$\pm 20\text{ V}$ max
Continuous Drain Current ( $I_D$ )	$-23\text{ A}$ ( $T_C = 25^\circ\text{C}$ ) / $-16\text{ A}$ ( $T_C = 100^\circ\text{C}$ )
Pulsed Drain Current ( $I_{DM}$ )	$-76\text{ A}$
On-Resistance ( $R_{DS(on)}$ at $-10\text{V}$ )	$117\text{ m}\Omega$ max ( $95\text{ m}\Omega$ typ) at $I_D = -11\text{A}$
Gate Threshold Voltage ( $V_{GS(th)}$ )	$-2.0\text{ V}$ to $-4.0\text{ V}$ ( $V_{GS} = -10\text{V}$ recommended for full conduction)
Total Power Dissipation ( $P_D$ )	$140\text{ Watts}$ ( $T_C = 25^\circ\text{C}$ with heatsink)
Operating Temperature Range	$-55^\circ\text{C}$ to $+175^\circ\text{C}$
Complementary N-Channel Pair	IRF540N / IRF540

Pinout (TO-220AB Package - G-D-S Standard)

Looking at the front labeled face with leads pointing downward:

text

        ┌──────────────┐
        │  O  [Metal]  │ ── Tab is internally connected to Pin 2 (Drain)
        ├──────────────┤
        │   IRF9540N   │
        └─┬────┬────┬──┘
          1    2    3
          G    D    S

Pin	Name	Type	Description
1	`GATE (G)`	Control Input	Gate control terminal (Pull LOW relative to Source to turn ON)
2 (Tab)	`DRAIN (D)`	Power Terminal	Drain output (Connected to switched load; internally bonded to tab)
3	`SOURCE (S)`	Power Terminal	Source input (Connected to positive power rail, e.g. $+24\text{V} \dots +48\text{V}$ )

Specifications

Parameter	Symbol	Min	Typ	Max	Unit	Conditions
Drain-Source Breakdown	$V_{(BR)DSS}$	-100	—	—	V	$I_D = -250\ \mu\text{A}, V_{GS} = 0\text{V}$
Gate Threshold Voltage	$V_{GS(th)}$	-2.0	—	-4.0	V	$V_{DS} = V_{GS}, I_D = -250\ \mu\text{A}$
Zero Gate Voltage Drain Current	$I_{DSS}$	—	—	-25	µA	$V_{DS} = -100\text{V}, V_{GS} = 0\text{V}$
Gate-Body Leakage Current	$I_{GSS}$	—	—	$\pm 100$	nA	$V_{GS} = \pm 20\text{V}, V_{DS} = 0\text{V}$
Static Drain-Source On-Resistance	$R_{DS(on)}$	—	95	117	mΩ	$V_{GS} = -10\text{V}, I_D = -11\text{A}$
Forward Transconductance	$g_{FS}$	5.3	—	—	S	$V_{DS} = -50\text{V}, I_D = -11\text{A}$
Total Gate Charge	$Q_g$	—	64	97	nC	$V_{GS} = -10\text{V}, V_{DS} = -80\text{V}, I_D = -11\text{A}$
Input Capacitance	$C_{iss}$	—	1300	—	pF	$V_{DS} = -25\text{V}, f = 1.0\text{MHz}$

Typical Application: Complementary Push-Pull MOSFET Power Amplifier (Class AB)

text

                            +35V to +45V Positive Power Supply
                                          │
                                   [Pin 3: SOURCE]
                                      IRF9540N (P-Channel)
  Audio VAS Input ────────────────►[Pin 1: GATE]
                                   [Pin 2: DRAIN]
                                          │
                                          ├───► Audio Output (to Speaker via 0.22Ω Resistor)
                                          │
                                   [Pin 2: DRAIN]
  Audio VAS Input ────────────────►[Pin 1: GATE]
                                      IRF540N (N-Channel)
                                   [Pin 3: SOURCE]
                                          │
                            -35V to -45V Negative Power Supply

Comparison: IRF9540N vs FQP27P06

Parameter	FQP27P06	IRF9540N
$V_{DSS}$ Voltage	$-60\text{ V}$	$-100\text{ V}$ (Higher Voltage Margin)
Max Current ( $I_D$ )	$-27\text{ A}$	$-23\text{ A}$
On-Resistance ( $R_{DS(on)}$ )	$70\text{ m}\Omega$	$117\text{ m}\Omega$
Power Dissipation ( $P_D$ )	$120\text{ W}$	$140\text{ W}$
Complementary N-Channel	FQP30N06L	IRF540N

Common mistakes

Attempting 3.3V/5V logic-level gate drive without a driver: The IRF9540 requires a gate-to-source voltage of $V_{GS} = -10\text{V}$ to achieve its rated $117\text{m}\Omega$ on-resistance. Applying only $-3.3\text{V}$ or $-5\text{V}$ leaves the transistor in its linear region, causing extreme overheating under load.
Forgetting that the metal mounting tab is connected to Drain: In TO-220 power MOSFETs, the tab is internally connected to Pin 2 (Drain). When mounting multiple MOSFETs to a shared heatsink, always use insulating mica/silicone pads and nylon washers.

Notes

Suffix Guide: IRF9540 is the original IR part ( $19\text{A}$ ); IRF9540N is the upgraded HEXFET generation ( $23\text{A}$ ); IRF9540NPBF indicates lead-free RoHS compliance.

Interface	Standard High-Side Gate Drive (-10V to -20V Recommended)
Package	TO-220AB (3-pin through-hole)