| Symptom | Probable Cause | Update Solution |
| :--- | :--- | :--- |
| Output stuck at 0V | No oscillator components on Pins 6 & 7 | Add RT=10k and CT=0.01uF as properties |
| Duty cycle stuck at 50% | Missing pull-up on output pins | Add a PULLUP model of 5V to Pins 11/14 |
| Proteus crashes on start | Conflicting HEX file version | Delete SG3524.HEX and use the Subcircuit method (Method 3) |
| No PWM modulation | Error amplifier inputs reversed | Swap Pin 1 and Pin 2 connections |
You will replicate the internal block diagram using standard components: sg3524 proteus library download upd
| SG3524 Pin | Function | Build using | |------------|---------------------|--------------------------------------| | 1, 2 | Error Amp Inputs | OPAMP (e.g., LM324) | | 3 | Feedback/Comp | Resistor + Cap to GND | | 4 | Current Limit Sense | Comparator + Voltage Source | | 5, 6 | RT, CT | External R, C (user sets) | | 7 | Discharge | Transistor + Resistor | | 8, 11, 14 | Outputs (E, C) | AND gates + Voltage-controlled switches | | 9, 10 | Emitters (Output) | NPN transistors | | 12 | GND | | | 13 | Output Control | Switch (toggles parallel/push-pull) | | 15 | Vcc | | | 16 | Vref | 5V regulator (use voltage source) | | Symptom | Probable Cause | Update Solution
Simpler approach: Download a ready-made Proteus VSM Model file (.MODEL) from a trusted source (see Method 2). This guide focuses on Method 1 (Manual creation)
This guide focuses on Method 1 (Manual creation) because it is safest and ensures future updates work.