Project Files of P-MOSFET Library for Proteus: IRF9540N, IRF4905 and BS250

P-MOSFET LIBRARY FOR PROTEUS - V1.0 (IRF9540N, IRF4905 and BS250 P-channel MOSFETs with a pop-up)
Designed by The Engineering Projects
www.TheEngineeringProjects.com

IMPORTANT LINKS
Article (read it first - pictures, step by step, every feature explained):
  https://www.theengineeringprojects.com/2026/11/p-mosfet-library-for-proteus.html
Report a bug or suggest a feature (our forum):
  https://www.theengineeringprojects.com/forum/category/p-mosfet-proteus-library
The demo runs on our Arduino UNO V4.0 (included) - working LEDs, RESET and a
built-in serial monitor, no Virtual Terminal to wire - its own article:
  https://www.theengineeringprojects.com/2026/10/arduino-uno-library-for-proteus-v40.html
The demo's loads are our own power resistors (included):
  https://www.theengineeringprojects.com/2026/11/power-resistor-library-for-proteus.html
its level shifter is the 2N7000 of our N-MOSFET library (included):
  https://www.theengineeringprojects.com/2026/11/n-mosfet-library-for-proteus.html
its LED is our own 5 mm LED (included):
  https://www.theengineeringprojects.com/2026/11/5mm-led-library-for-proteus.html
Support us (the libraries are free):
  https://www.theengineeringprojects.com/donate

FILE STRUCTURE
P-MOSFET-TEP-v1.0/
|-- Proteus Library Files/
|   |-- ArduinoV4TEP.LIB                              201.9 KB   TEP Arduino boards V4.0 (UNO) -> LIBRARY
|   |-- TEPLED5MM.LIB                                  21.8 KB   a part the demo uses -> LIBRARY folder
|   |-- TEPNMOS.LIB                                    17.9 KB   a part the demo uses -> LIBRARY folder
|   |-- TEPPMOS.LIB                                    17.9 KB   the library -> LIBRARY folder
|   |-- TEPPOWERRES.LIB                               157.2 KB   a part the demo uses -> LIBRARY folder
|   |-- TEPRESISTOR.LIB                               306.9 KB   a part the demo uses -> LIBRARY folder
|-- Proteus Model Files/
|   |-- TEPARDUINO.DLL                                883.5 KB   the Arduino board model -> MODELS folder
|   |-- TEPLED5MM.DLL                                 289.5 KB   its model -> MODELS folder
|   |-- TEPNMOS.DLL                                   295.0 KB   its model -> MODELS folder
|   |-- TEPPMOS.DLL                                   295.5 KB   the model -> MODELS folder
|   |-- TEPPOWERRES.DLL                               304.5 KB   its model -> MODELS folder
|   |-- TEPRESISTOR.DLL                               311.0 KB   its model -> MODELS folder
|-- Proteus Simulation/
|   |-- PMOS_Demo.hex                                   9.8 KB   the demo firmware
|   |-- P-MOSFET-High-Side-ArduinoUnoV4.pdsprj         26.6 KB   the demo project
|   |-- TEPARDUINO.DLL                                883.5 KB   copy of the board model
|   |-- TEPLED5MM.DLL                                 289.5 KB   copy of its model
|   |-- TEPNMOS.DLL                                   295.0 KB   copy of its model
|   |-- TEPPMOS.DLL                                   295.5 KB   copy of the model
|   |-- TEPPOWERRES.DLL                               304.5 KB   copy of its model
|   |-- TEPRESISTOR.DLL                               311.0 KB   copy of its model
|-- Arduino Code/
|   |-- PMOS_Demo/PMOS_Demo.ino                         2.2 KB   the demo sketch (source of the .hex)
|-- README.txt                                        ~14.3 KB   this file
Total: 5.40 MB (unzipped). The C++ source code of the models is not included.

WHAT IS IT?
Three P-channel MOSFETs, drawn at true scale - the high-side switch: source on the supply, load from
drain to ground:
  * IRF9540N - TO-220 (G D S, the tab is D): -100 V, -23 A, 117 mohm at -10 V on its gate.
  * IRF4905 - TO-220: -55 V, -74 A, 20 mohm at -10 V on its gate.
  * BS250 - small signal, TO-92 (S G D): -45 V, -230 mA, about 14 ohm.
  * One analog model: the channel (a square law with a smooth threshold, the triode and saturation
    regions, channel-length modulation, the drain's
    series resistance), the gate capacitance Ciss, the body diode (from D to S), and the junction
    temperature through the heatsink
    (HEATSINK NONE, SMALL, LARGE on the TO-220 parts); past its limit it fails short D-S.
  * It is on when its gate is pulled BELOW its source. It names its region (OFF, ON, SATURATION,
    PWM, DIODE ON), warns when it is under-driven,
    and draws its output curves with the working point. Every value keeps its real sign (Vgs -12 V,
    Vds -9 mV).
    Click one at Run for the pop-up: the region, Rds now, the gate drive against its rating, the
    curves, graphs, an event log and a check page.
The body is drawn as on the real part and to true scale against our Arduino.
The TEP signature and the pop-up are TEP additions.

THREE DEVICES (search "IRF9540", "IRF4905" or "BS250" in Pick Devices):
  IRF9540NTEP  "IRF9540N P-MOSFET V1.0" in TEPPMOS.LIB (Transistors > MOSFET), prefix Q, model
  TEPPMOS.DLL. Pins 1 G, 2 D, 3 S.
  IRF4905TEP   "IRF4905 P-MOSFET V1.0" in TEPPMOS.LIB, prefix Q, model TEPPMOS.DLL. Pins 1 G, 2 D, 3
  S.
  BS250TEP     "BS250 P-MOSFET V1.0" in TEPPMOS.LIB, prefix Q, model TEPPMOS.DLL. Pins 1 S, 2 G, 3
  D.

THE POP-UP
Click the part at Run. Tabs:
    MOSFET     the region with the current and Rds, the package with its live pins, the gate drive
    (how far below its source) against its threshold
               and its rating, the output curves (-Id against -Vds at four gate voltages) with the
               working point, and eight live values.
               The toolbar: New part, the pins, the heatsink.
    Graphs     the live values over the last 2, 6 or 15 s. Live / Freeze.
    Event log  every change and warning; filters All / Changes / Warnings, Pause, Clear
    Check      what the part is doing and what to look at, each with a verdict (green = fine, amber
    = check, red = wrong)
    Settings   theme, text size, open at Run, window size
    Help       report a bug, suggest a feature, article, updates, donate, forum; Copy diagnostics
    for a bug report

TEST STATUS
V1.0: verified in Proteus 8.5 on 31 Oct 2026 (the demo project as shipped: an A4 sheet, an Arduino UNO V4.0).
What the runs showed (the model's own numbers and the sketch's monitor):
  * The project loads and starts cleanly; all four MOSFETs follow the sketch from the first step.
  * Step 1, all on: the IRF4905 on +12V, its gate pulled down by the 2N7000 level shifter, saw Vgs
    -11.99 V and carried 545 mA through
    17.3 mohm (Vds -9 mV, 5.2 mW) - its Check page: fully on, 17 mohm against its rated 20 mohm at
    -10 V.
    The IRF9540N, its gate straight from a 5 V pin, saw only Vgs -4.88 V: 224 mA through 303 mohm
    (Vds -68 mV, 15.2 mW) - its log warned
    UNDER-DRIVEN and its Check page compares 303 mohm with its 117 mohm at -10 V.
    The BS250 lit the red LED: Vgs -5.00 V, 6.48 mA through 31.4 ohm. The 2N7000 carried the 1.20 mA
    of R1's pull-up through 4.91 ohm.
  * Step 2, the IRF4905 at 50 % PWM: its pop-up read the gate as PWM at 490 Hz, about 51 % on - one
    line in the log, not three an edge.
  * Step 3, all off: the full -12.000 V across the IRF4905 and -5.000 V across the IRF9540N, both
    gates at 0.00 V (the pull-ups to the source);
    then step 4, the IRF9540N alone. The monitor printed every step.
  * Each gate charge drew a short pulse: about 375 mA into the IRF4905's 3.4 nF through the 2N7000,
    20 mA into the IRF9540N's 1.3 nF through R4 (220).
  * The pop-up: MOSFET, Graphs, Event log, Check - all four pages followed the run, for all three
    P-MOSFETs, with the real (negative) signs.

INSTALLATION (about 2 minutes)
1. Close Proteus. Extract the WHOLE ZIP to a normal folder (e.g. Desktop).
2. Copy everything in "Proteus Library Files" (TEPPMOS.LIB, TEPRESISTOR.LIB, TEPPOWERRES.LIB,
TEPLED5MM.LIB, TEPNMOS.LIB and our Arduino library V4.0, ArduinoV4TEP.LIB, with the ARDUINO UNO V4.0
used by the demo) to the LIBRARY folder of Proteus, for example:
     C:\Program Files (x86)\Labcenter Electronics\Proteus 8 Professional\LIBRARY
   (use the folder that already holds Proteus's own .LIB files).
3. Copy TEPPMOS.DLL, TEPRESISTOR.DLL, TEPPOWERRES.DLL, TEPLED5MM.DLL, TEPNMOS.DLL and TEPARDUINO.DLL
from "Proteus Model Files" to the MODELS folder (...\Proteus 8 Professional\MODELS).
4. Delete TEPPMOS.IDX from the LIBRARY folder if it is there (Proteus makes a new index).
5. Start Proteus. In Pick Devices (P) search "IRF9540, IRF4905 or BS250".

RUN THE DEMO
"Proteus Simulation\P-MOSFET-High-Side-ArduinoUnoV4.pdsprj" (an A4 sheet) - keep the .hex file and
the DLLs beside the project.
  ARD1:   Arduino UNO V4.0 running PMOS_Demo.hex, its serial monitor built in (window "TEP Arduino
  UNO - ARD1").
  Q1 IRF4905: source on +12V; R1 10k from +12V to the gate (off); Q4, a 2N7000 from D9 through R3
  (100), pulls the gate to GND (on);
              drain - R2 (our 10 W power resistor, 22 ohm) - GND.
  Q2 IRF9540N: source on +5V; D10 - R4 220 - gate, R5 10k gate to +5V; drain - R6 (22 ohm, 10 W) -
  GND.
  Q3 BS250:   source on +5V; D8 - R7 100 - gate; drain - D1 (our red LED) - R8 470 - GND.
  1. Press Run. Every 2.5 s the next step: all on / Q1 at 50 % PWM, the others off / all off / Q2
  alone.
  2. Compare Q1 and Q2's pop-ups: Q1 gets the full -12 V on its gate, Q2 only the -5 V a pin can
  give.
Closed the monitor? Click the UNO's USB port.

WIRING (the same in Proteus and on a real board)
  source on +V; 10k gate to source (off); load from drain to GND                  (high side)
  supply above 5 V: an NPN or N-MOSFET pulls the gate to GND - a pin can never pull it up to the
  supply
  from a 5 V pin on a 5 V supply: pin - 100 to 220 ohm - gate; LOW = on
REAL HARDWARE:
 * A P-MOSFET is on when its gate is BELOW its source: Vgs is negative. Its threshold and Rds
   ratings are given at -4.5 V or -10 V.
 * With a supply above 5 V, drive the gate through a small NPN or N-MOSFET with a pull-up (10k) from
   the gate to the source.
 * Keep the gate within its rating (about -20 V): above that, a zener from gate to source.
 * The body diode runs from D to S: across a coil you still need a flyback diode.
 * The tab of a TO-220 MOSFET is the drain: insulate it from a grounded heatsink.

THE DEMO SKETCH ON THE SERIAL MONITOR (PMOS_Demo V1.0, 9600 baud)
There are no commands. The sketch steps every 2.5 s and prints each step.
EXPECTED MONITOR OUTPUT
  P-MOSFETs - The Engineering Projects
  Step 1: all on
  Step 2: Q1 at 50 % PWM, the others off

PROPERTIES (double-click the part > Edit Properties)
  Part (VALUE)                     IRF9540N, IRF4905 or BS250
  Heatsink (TO-220 only)           NONE (62 C/W, 2.0 W safe), SMALL (15 + 1.5 C/W, 7.6 W), LARGE (5
  + 1.5 C/W, 19 W)
Every run starts again from the properties.

LINKS.INI (OPTIONAL)
The Help page cards of the pop-up open web pages. To point them somewhere else without a new DLL,
put a text file named links.ini next to TEPPMOS.DLL with lines KEY=URL, for example:
  ARTICLE=https://www.theengineeringprojects.com/...
Keys: WEBSITE, FORUM, BUG_REPORT, FEATURE_REQUEST, ARTICLE, USER_GUIDE,
UPDATE_CHECK, DONATE. Only http:// and https:// links are used; lines starting
with # are comments.

TROUBLESHOOTING
* UNDER-DRIVEN: the gate is not far enough below the source for its rated Rds - a level shifter to
  pull it lower.
* It never turns off on a 12 V supply: a 5 V pin cannot reach the supply - an NPN or N-MOSFET with a
  pull-up to the source.
* It turns on by itself: the gate floats - add a pull-up from gate to source.
* TOO HOT: the junction passed its limit - a heatsink, or a part with a lower Rds.
* The part is not simulated: TEPPMOS.DLL is missing from MODELS and from the project folder. No UNO
  / no monitor window: TEPARDUINO.DLL is missing, or click the UNO's USB port.

BUG REPORTS AND FEATURE REQUESTS
Please post them in our forum with a screenshot, the Serial Monitor text, the
simulation log and the pop-up's Copy diagnostics text:
  https://www.theengineeringprojects.com/forum/category/p-mosfet-proteus-library

SUPPORT US
This library is free. If it saves you time, please support our work:
  https://www.theengineeringprojects.com/donate

WEBSITE
  https://www.theengineeringprojects.com/

LICENCES AND THIRD-PARTY NOTES
* The model (TEPPMOS.DLL), the symbols and artwork, the other parts of ours in the demo and the
  Arduino Library V4.0 (ArduinoV4TEP.LIB / TEPARDUINO.DLL, with its built-in TEP Serial Monitor
  Advance) are made by The Engineering Projects. The models use only standard Windows libraries; no
  Visual C++ redistributable is needed.
  The C++ source code is not included.
* Arduino UNO V4.0 (ArduinoV4TEP.LIB / TEPARDUINO.DLL, our Arduino Library V4.0 - its
  microcontroller is Proteus's own AVR model): The Engineering Projects,
  https://www.theengineeringprojects.com/2026/10/arduino-uno-library-for-proteus-v40.html
* The .hex file is built from the demo sketch and the Arduino AVR core 1.8.6, which includes
  LGPL-licensed code; its source code is available at
  https://github.com/arduino/ArduinoCore-avr/tree/1.8.6
* Proteus is a product of Labcenter Electronics and is not included. Arduino is a trademark of Arduino SA.
  This library is not made or endorsed by Arduino or Labcenter.

REBUILDING THE FIRMWARE (OPTIONAL)
The HEX file is supplied; Arduino IDE is not needed to run the demo. To edit the sketch, open
Arduino Code\PMOS_Demo\PMOS_Demo.ino, select Arduino Uno and use Sketch > Export Compiled Binary.
Replace the simulation's .hex with the exported HEX. The sketch needs 3,544 bytes of flash and 299
bytes of RAM.

MODEL SCOPE AND LIMITS
Modelled: the channel with its threshold, the triode and saturation regions, channel-length
modulation, the drain resistance, the gate capacitance,
the body diode, the junction temperature through the heatsink, the failure.
Not modelled: the Miller plateau and the gate-drain capacitance, the switching losses, avalanche.

VERSION
TEP P-MOSFET library V1.0 (Nov 2026). Devices IRF9540NTEP, IRF4905TEP and BS250TEP (TEPPMOS.LIB /
TEPPMOS.DLL). Demo sketch PMOS_Demo V1.0. Demo board: ARDUINO UNO V4.0 (TEP Arduino Library V4.0)
with its built-in serial monitor.