USB-PD AC Adapter
This page describes the USB-PD AC adapter requirements for the Zudo Power USB-PD power supply module.
Required Specifications
| Specification | Requirement |
|---|---|
| Connector | USB Type-C |
| Protocol | USB Power Delivery (PD) |
| Required PDO | 15V / 3A (45W at 15V) |
| Minimum Power | 45W |
| Recommended | 65W or higher |
Why 15V / 3A?
This power supply uses the STUSB4500 USB-PD controller to negotiate 15V from the adapter. The STUSB4500 is configured via NVM to request specifically 15V PDO (Power Data Object).
Power Budget Calculation:
| Output Rail | Current | Power |
|---|---|---|
| +12V | 1.5A | 18W |
| -12V | 1.0A | 12W |
| +5V | 1.5A | 7.5W |
| Total Output | - | 37.5W |
Accounting for conversion efficiency (~75-80%), the input power required is approximately 35-40W. A 45W adapter (15V/3A) meets this requirement with some margin.
Important Considerations
1. Must Support 15V PDO
Critical: The adapter must explicitly support 15V in its PDO profile.
Some cheaper adapters only support:
- 5V / 9V / 20V (skipping 15V)
Always verify the product specifications list 15V as a supported voltage.
2. Single Port Usage (For Single zudo-PD)
When using multi-port adapters with a single zudo-PD unit, power is typically split between ports. For reliable operation:
- Use single USB-C port for full power delivery
- If using multi-port, ensure the port supports 45W+ when used alone
Note: For multi-case setups with multiple zudo-PD units, using a single high-wattage multi-port charger is actually recommended. See Multi-Case Setup below.
3. GaN Technology Recommended
GaN (Gallium Nitride) adapters offer:
- Smaller size
- Higher efficiency
- Lower heat generation
- Better reliability
4. Avoid No-Brand Adapters
Cheap no-brand adapters may:
- Have unstable voltage output
- Skip 15V PDO entirely
- Lack proper safety certifications (PSE in Japan)
Recommended Products (Amazon Japan)
Top Recommendations
| Brand | Model | Power | 15V Support | Ports | Price Range |
|---|---|---|---|---|---|
| Anker | Nano II 65W | 65W | 15V/3A | 1x USB-C | ~4,000 |
| Anker | Nano II 45W | 45W | 15V/3A | 1x USB-C | ~3,000 |
| UGREEN | Nexode 65W | 65W | 15V/3A | 2x USB-C + 1x USB-A | ~4,500 |
| BESTEK | G651CA1 | 65W | 15V/3A | 1x USB-C + 1x USB-A | ~3,000 |
| Belkin | WCH013dq | 65W | 15V | 2x USB-C | ~5,000 |
| CIO | NovaPort SLIM 45W | 45W | 15V | 2x USB-C | ~4,000 |
Product Links
-
Anker Nano II 65W - Best overall choice
- Compact design with GaN II technology
- Proven reliability
- Output: 5V/3A, 9V/3A, 15V/3A, 20V/3.25A
-
Anker Nano II 45W - Minimum spec, most compact
- Smallest form factor
- PPS support
- Output: 5V/3A, 9V/3A, 15V/3A, 20V/2.25A
-
UGREEN Nexode 65W - Best value with multiple ports
- 3 ports for versatility
- GaN II technology
- PD3.0 and PPS support
-
BESTEK G651CA1 65W - Budget option
- Explicitly lists 15V/3A support
- Compact design (~102g)
-
Belkin WCH013dq 65W - Premium option
- Trusted brand
- 5V/9V/12V/15V/20V support
- Dual USB-C ports
-
CIO NovaPort SLIM 45W - Ultra-thin design
- Only 13mm thick
- Dual USB-C ports
Verification Before Purchase
Before purchasing, check the product page for:
- PDO List - Should include 15V (e.g., "5V/9V/15V/20V")
- Power at 15V - Should be at least 3A (45W)
- Safety Certification - PSE mark for Japan
- Reviews - Check for stability issues
USB-PD Controller Compatibility with Multi-Port GaN Chargers
Known Issue: High-Wattage Multi-Port Chargers May Not Work
Important Discovery: Some high-wattage multi-port GaN chargers may have compatibility issues with simple PD sink controllers. The v1.1 design uses STUSB4500 which has significantly better charger compatibility (~95%+) compared to the v1.0 CH224D design (~33%).
Confirmed Working
| Charger | Model | Power | Ports | Status |
|---|---|---|---|---|
| Anker Nano II 65W | A2663 | 65W | 1× USB-C | ✅ Works perfectly |
Confirmed NOT Working
| Charger | Model | Power | Ports | Status |
|---|---|---|---|---|
| Anker Prime 200W | A2683 | 200W | 4× USB-C + 2× USB-A | ❌ All ports fail |
| Elecom | EC-AC67150BK | 150W | 3× USB-C + 1× USB-A | ❌ All ports fail |
Why This Happens
Simple PD sink controllers may have limited negotiation capabilities compared to the sophisticated software PD stacks in laptops and tablets. Multi-port GaN chargers with intelligent power management expect active, responsive PD sinks.
Comparison: Simple vs Advanced PD Controllers
| Aspect | PC / iPad | Simple PD Sink (e.g., CH224D) | STUSB4500 (v1.1) |
|---|---|---|---|
| PD Controller | Full software stack with dedicated IC | Simple hardware-only sink IC | USB-IF certified sink IC |
| Negotiation | Active, bi-directional communication | Passive, one-shot request | Active with retry logic |
| Retries | Multiple retry attempts with backoff | Limited or no retry logic | Built-in retry mechanism |
| Timing Tolerance | Flexible, handles delays | Strict timing requirements | Flexible timing |
| Re-negotiation | Handles dynamic PDO changes | May fail on PDO updates | Handles re-negotiation |
| Error Recovery | Sophisticated error handling | Falls back to 5V or fails | Built-in error recovery |
The STUSB4500 used in v1.1 addresses most of these issues with USB-IF certification and built-in retry logic.
Root Causes
1. Dynamic Power Management Interference
Multi-port chargers constantly redistribute power as devices connect/disconnect. Features like:
- Anker PowerIQ / ActiveShield - Proprietary device detection
- Dynamic PDO re-advertisement - Changes available power in real-time
- Intelligent power sharing - May confuse simple sink controllers
2. Non-Standard Timing
Some high-wattage chargers:
- Output 0V initially until specific conditions are met
- Have longer negotiation sequences
- Use stricter CC line detection than USB PD specification requires
3. Missing 5V PDO (Some Chargers)
Some chargers violate USB PD specification by not including 5V as PDO1:
- USB PD spec requires 5V as the first PDO
- When CH224D receives Source_Capabilities starting at 9V, negotiation fails
- Device falls back to pre-PD 5V default (insufficient for zudo-PD)
Symptoms When Charger Is Incompatible
When connecting zudo-PD to an incompatible charger:
- Only the -12V LED briefly flickers
- All LEDs turn off
- No output voltage on any rail
Explanation: With only 5V input (failed negotiation), the DC-DC converters cannot produce proper voltages. The ICL7660 voltage inverter briefly attempts to invert whatever voltage exists, causing the -12V LED to flicker momentarily.
Recommendations
For Best Compatibility
| Charger Type | Compatibility |
|---|---|
| Single-port PD chargers | ✅ Best - Simple negotiation |
| Laptop chargers (65W-100W) | ✅ Usually works |
| Multi-port chargers <100W | ⚠️ Test before relying on |
| Multi-port GaN >100W | ❌ Often fails |
Recommended Approach
- Use a dedicated single-port charger for zudo-PD
- Test before purchasing - If possible, test with your specific charger before committing to a setup
- Avoid high-wattage multi-port GaN chargers unless confirmed working
Multi-Case Setup Caveat
The Multi-Case Setup section recommends multi-port chargers for ground loop elimination. However, due to potential compatibility issues:
- Preferred: Use confirmed-working chargers (like Anker Nano II series)
- Alternative: Accept separate adapters with proper ground management
- Testing required: Always test multi-port chargers before relying on them for live performance
STUSB4500 Improves Compatibility (v1.1)
The v1.1 design uses the STUSB4500 USB-IF certified controller, which significantly improves charger compatibility (~95%+) compared to the v1.0 CH224D design (~33%). The STUSB4500 includes built-in retry logic and error recovery that resolves most compatibility issues with modern GaN chargers.
Troubleshooting
Adapter Not Working
If the power supply doesn't work with your adapter:
- Check PDO support - Adapter may not support 15V
- Check cable - Use a USB-C cable rated for 3A or higher
- Check port - Some multi-port adapters reduce power on certain ports
LED Not Lighting
If LED2 (power indicator) doesn't light:
- Verify adapter is connected and powered
- Try a different USB-C cable
- Verify adapter supports 15V PDO
Multi-Case Setup (Multiple zudo-PD Units)
When you need more power for a larger modular synth system, you can power multiple zudo-PD units from a single multi-port USB-PD charger. This approach has significant benefits over using separate AC adapters.
Why Use a Single Multi-Port Charger?
Ground Loop Elimination:
When using separate AC adapters for each case, connecting modules via patch cables creates ground loops:
Separate Adapters (BAD):
┌─────────────────┐ ┌─────────────────┐
│ Adapter A │ │ Adapter B │
│ GND_A │ │ GND_B │
└────────┬────────┘ └────────┬────────┘
│ │
┌────┴────┐ ┌────┴────┐
│ Case A │◄───patch cable───│ Case B │
└─────────┘ (has ground) └─────────┘
│ │
└─────── ground loop ────────┘
↑
Potential 50/60Hz hum
Single multi-port charger solves this:
Single Multi-Port Adapter (GOOD):
┌─────────────────────────────┐
│ Multi-Port GaN Charger │
│ (shared internal ground) │
└──────┬─────────────┬────────┘
│ │
┌───┴───┐ ┌───┴───┐
│zudo-PD│ │zudo-PD│
│ Case A│◄───►│ Case B│ ← Patch cables OK!
└───────┘ └───────┘
No ground loop - both share same ground reference!
Power Requirements
Each zudo-PD unit requires approximately 40W at 15V (15V × 2.5A with some margin).
| Setup | Power Required | Minimum Charger |
|---|---|---|
| 2 units | ~80W | 100W charger |
| 3 units | ~120W | 150W charger |
| 4 units | ~160W | 200W charger |
Important Considerations
- 15V must be maintained on all ports - Some chargers drop to 9V when power is split
- Check simultaneous output specs - Not just total wattage, but per-port when multiple ports are used
- USB Hubs don't work - Regular USB hubs only provide 5V, not USB-PD
⚠️ Critical Compatibility Warning
The multi-port chargers listed below have NOT been tested with zudo-PD. Based on our testing (see USB-PD Controller Compatibility), high-wattage multi-port GaN chargers often fail to work with the CH224D controller (v1.0 design). The STUSB4500 (v1.1) improves this significantly.
Confirmed NOT working:
- Anker Prime 200W (A2683) - ❌ All ports fail
- Elecom EC-AC67150BK (150W) - ❌ All ports fail
Before purchasing any multi-port charger for multi-case setup:
- Check if the specific model has been tested with CH224D-based devices
- Consider using multiple single-port chargers instead (with ground loop mitigation)
- Test before relying on for live performance
Multi-Port Chargers (Untested - Use at Your Own Risk)
The following chargers have sufficient power specifications but have not been verified to work with zudo-PD:
For 2 zudo-PD Units
| Brand | Model | Power | Ports | Simultaneous Output | Compatibility |
|---|---|---|---|---|---|
| Anker | Prime 200W (A2683) | 200W | 4× USB-C | 100W + 100W | ❌ Confirmed NOT working |
| UGREEN | Nexode 200W Desktop | 200W | 4× USB-C + 2× USB-A | 100W + 100W | ❓ Untested |
| UGREEN | Nexode 100W | 100W | 3× USB-C + 1× USB-A | 65W + 30W | ❓ Untested |
For 3 zudo-PD Units
| Brand | Model | Power | Ports | Compatibility |
|---|---|---|---|---|
| Anker | Prime 250W | 250W | 4× USB-C + 2× USB-A | ❓ Untested |
| Anker | Prime 200W (A2683) | 200W | 4× USB-C | ❌ Confirmed NOT working |
| UGREEN | Nexode 200W Desktop | 200W | 6 ports | ❓ Untested |
Note: If you find a multi-port charger that works with zudo-PD, please report it so we can update this list.
Verification Checklist
Before purchasing a multi-port charger for multi-case setup:
- Total wattage ≥ (number of units × 45W)
- Supports 15V PDO on multiple ports simultaneously
- Check reviews for multi-device usage scenarios
- Verify power distribution when all ports are used (check manual or QR code specs)
Alternative: Separate Single-Port Adapters
Given the compatibility issues with multi-port GaN chargers, using separate single-port adapters may be more reliable:
Pros:
- ✅ Confirmed working (Anker Nano II 65W tested)
- ✅ Simple, predictable PD negotiation
- ✅ Each unit has dedicated power
Cons:
- ⚠️ Potential ground loops when connecting patch cables between cases
- ⚠️ More wall outlets needed
Ground Loop Mitigation (if using separate adapters):
- Use balanced audio connections where possible
- Ground lift on one case (if your synth supports it)
- Use the same power strip for all adapters (shared AC ground)
- Avoid connecting patch cables between separately-powered cases during performance