Difference Between QC (Quick Charge) and PD (Power Delivery) Chargers

The key difference between QC (Quick Charge) and PD (Power Delivery) chargers lies in their origin, power output capabilities, compatibility, and charging protocols. Here's a detailed comparison between the two:

1. Developed By:

• QC (Quick Charge): Developed by Qualcomm, primarily for devices with Snapdragon processors, though other manufacturers also use it.
• PD (Power Delivery): Developed by the USB Implementers Forum (USB-IF) as part of the USB-C standard, designed for universal device compatibility.

2. Power Output:

• QC (Quick Charge):
  • QC 3.0: Delivers up to 18W of power.
  • QC 4.0/4.0+: Can deliver up to 100W, but typically provides 27W or less for smartphones.
• PD (Power Delivery):
  • PD 3.0: Supports up to 100W (20V/5A), making it ideal for devices requiring higher power like laptops, tablets, and smartphones.

3. Device Compatibility:

• QC (Quick Charge): Primarily used in Android smartphones with Qualcomm Snapdragon processors. Not compatible with all devices—for example, Apple devices do not support QC.
• PD (Power Delivery): PD power supply Works across a wide variety of devices, including Android, Apple devices, laptops, gaming consoles (like the Nintendo Switch), and tablets. More universally compatible due to being part of the USB-C standard.

4. Charging Speed:

• QC (Quick Charge): Provides fast charging for smartphones that support Qualcomm’s protocol, especially for Snapdragon-powered Android devices.
• PD (Power Delivery): Typically provides faster charging than QC, especially for high-power devices like laptops. PD can deliver different voltages (5V, 9V, 12V, 15V, 20V) depending on the device’s needs, optimizing charging speed for each device.

5. Charging Flexibility:

• QC (Quick Charge): Limited mostly to smartphones and smaller devices, although QC 4.0+ can support some higher-power devices.
• PD (Power Delivery): More versatile, capable of charging smartphones, tablets, laptops, gaming consoles, and more. PD chargers can automatically adjust to the device’s power requirements, delivering the right voltage and current for fast and safe charging.

6. Power Negotiation:

• QC (Quick Charge): Adjusts the voltage dynamically (e.g., 3.6V to 20V), but it’s less sophisticated compared to PD. Primarily focuses on increasing the voltage for faster charging.
• PD (Power Delivery): Uses a more advanced power negotiation system. Devices and chargers communicate to find the optimal power level, allowing for safe and efficient charging.

7. Connector Type:

• QC (Quick Charge): Earlier versions used USB-A connectors, but QC 4.0+ now supports USB-C. However, it's still less common with USB-C than PD.
• PD (Power Delivery): Exclusively uses USB-C, which allows for higher power delivery and faster data transfer rates, making it the standard for modern charging.

8. Safety & Efficiency:

• QC (Quick Charge): While efficient and fast, QC is mostly used in smartphones. It relies on a simpler voltage adjustment mechanism and may not offer the same level of efficiency and safety as PD.
• PD (Power Delivery): Provides smarter, more efficient power delivery. It ensures devices get exactly the power they need, protecting against overcharging and overheating. This makes PD more efficient and battery-friendly.

9. Bidirectional Charging:

• QC (Quick Charge): Limited to powering up devices, does not typically support bidirectional charging.
• PD (Power Delivery): Supports bidirectional power. For instance, a laptop could charge a smartphone, and a smartphone could power another device, like headphones, if needed.

10. Backward Compatibility:

• QC (Quick Charge): Backward compatible with older Quick Charge standards (e.g., QC 3.0 is compatible with QC 2.0 devices).
• PD (Power Delivery): Compatible with non-PD devices, though it will provide standard charging speeds when a device does not support fast charging.

Summary of Differences:

Item	Power Delivery (PD)	Quick Charge (QC)	Standard Charging
Power	10W - 100W	10W - 100W	5W - 10W
Supported Electronic Devices	More	Only supports mobile phones	Less
Estimated time to fully charge a mobile phone	30 - 60 minutes	30 - 60 minutes	2 - 3 hours
Estimated time to fully charge a tablet	1 - 2 hours	2 - 3 hours	3 - 4 hours
Charging Protocol	USB-C with PD protocol	USB-A with QC protocol	No protocols

Which to Choose:

• Quick Charge (QC) is ideal for fast charging smartphones, especially Android devices with Snapdragon processors. It is useful if your focus is on mobile devices, and you need backward compatibility with earlier QC versions.

• Power Delivery (PD) is the better option if you want a more versatile solution that works across multiple devices, including laptops, tablets, smartphones, and more. PD also offers higher power and more efficient charging with better safety features.

Would you like more details on how to integrate QC or PD chargers into your products?