Key features
TinyPPS now takes advantage of pin-compatible USB PD sink ICs (AP33772 and AP33772S), providing two feature sets within a single firmware, depending on the selected IC:
| Feature | With AP33772s | With AP33772 |
|---|---|---|
| Supported PDO profiles | fixed PDO, PPS | fixed PDO, PPS |
| Output voltage range | 3.3 - 21V | 3.3 - 21V |
| Max output current* | 5A | 5A |
| PPS voltage step size | 100mV/Step | 20mV/Step |
| Programmable current limit | 250mA/Step | 50mA/Step |
| User-switchable output | ✅ | ✅ |
| Over Voltage Protection (OVP) | ✅ → Hard Reset and Auto Restart | ✅ → Auto Restart |
| Over Current Protection (OCP) | ✅ → Output Disable | ✅ → Auto Restart |
| Under Voltage Protection (UVP) | ✅ → Output Disable | ❌ |
| Over temperature protection (OTP)** | ✅ → Output Disable | ✅ → Output Disable |
| Short-Circuit Protection (SCP) | ✅ → Output Disable | ✅ → Output Disable |
*charger and cable dependent
**OTP is set to 85°C
For a detailed look at the schematics, PCB design and firmware, visit the GitHub repository.
Sponsor time
Huge thank you to PCBWay for providing me PCBs and SMD stencil for free.
PCBWay offers high-quality PCBs at affordable prices. The boards are ready to solder straight out of the box, with no leftover tabs that need to be sanded down. Ordering is super easy: just upload the Gerber files and select the desired parameters.
What I like most is their customer support. They are quick to review orders and don’t just point out issues - they provide detailed explanations on how to address them. Whether it is about a missing Gerber file or out of capabilies issue. At the end, the outcome is always positive.