last updated 19 Jan 2020
Contents: Intro| Quick Charge (QC) | USB Power Delivery (USB PD) | QC device list | Max device watts | Terms/Glossary


Standard  USB QC        USB PD 
  USB     Quick         Power
          Charge      Distribution
Charging for laptops, tablets, USB-powered disks and similarly higher-power consumer electronics.

Quick Charge (QC)is a proprietary technology which allows for the charging of battery powered devices, primarily mobile phones, at levels above and beyond the typical 5 volts and 2-2.4 amps for which most USB standards allow.
The device being charged must ask for higher voltages, otherwise it sticks to the 5 V standard, so non QC devices can be connected to QC wall charger.

Charging power varies over the charging cycle. QC 3.0 ranges are 3.6 - 22 V; 2.6 or 4.6 A; Max of 36 W (12 V * 3 A)

USB Power Distribution (PD) was designed for laptops with up to 100 Watts.
It is similar to QC, providing variable voltage over the charging cycle
Typically QC and PD is supplied on the same UCB-C port on wall charge bricks and Charging Stations.

Qualcom Quick Charge (QC) QC Qualcomm's Quick Charge chip in newer android devices charges 4 times faster than 1A charging.
QC 3.0 is a charging protocol designed by Qualcomm, it offers stepless multi-voltage charging from 3.7V to 20V; your device can receive the perfect voltage and current optimized to its exact charging state. Your device needs to support Quick Charge to receive any benefit.

Several other rapid-charging technologies are based on Quick Charge 2.0; these include TurboPower (Motorola), Adaptive Fast Charging (Samsung), Dual-Engine Fast Charging (Vivo) and BoostMaster (Asus).
Huawei’s 10V/4A SuperCharge produces 40W and Samsung’s latest Adaptive Fast Charging produces 15W of juice.

It is designed to work USB Type-A, micro USB, and USB Type-C

USB-C MPD ?? - I couldn't find what this is. I think it's a typo.
MPD is an MPC (Music Production Center) Audio interface.

Most devices are protected in that they will only draw the amount of current required despite higher capacity of a port.
To get higher voltage on QC ports they have to request it. ©

QC device list: Smartphones and Tablets with Qualcomm Quickcharge Support | PowerBankGuide Jan, 2019 What is the difference between Class A and Class B accessories?
A: The difference is the maximum voltage. Both Class A and Class B adapters are rated at 5, 9 and 12 volts. Class B adapters go one step further, up to 20 volts. Class B adapters are large enough to charge devices that need more power, such as a notebook computers. Remember, Quick Charge is engineered to deliver only the power needed for the device it's charging, so a Class B adapter can be used for a smartphone or laptop.

USB Power Delivery (USB PD)

Laptop charging:
Almost all computers that charge via USB-C have a maximum charge speed of 60 watts—the 15-inch MacBook Pro can charge at up to 87 watts.
Usb-C Chargers provide the fastest and most efficient output current (5V/3a, 9V/3a, 12V/3a, 15V/3a, 20V/3a).

Max Watts for devices:
iPhone 6: 8 W
iPhone 7: 10.5 W
iPhone 8 & X: 12 W
iPhone 11 Pro: 18 W PD
iPad Pro: 18 W
Samsung Galaxy Note 10: 25 W
Samsung Galaxy Note 10+: 45 W
Laptops: 60 W
Macbook Pro 87 W
USB C Wall Charger, 18W PD 3.0 , Fast Charging $10

In the 90's mobile devices used proprietary charging connectors connected to serial ports, which computers had before USB.
In 1998, the iMac G3 was the first consumer computer to discontinue legacy ports (serial and parallel) in favor of USB.
2012 - USB Power Delivery (PD) standardized
In 2015 QualCom introduced Quick Charge (QC) 3.0
2018 QC 4.0


AICL Automatic Input Current Limit
APSD Automatic Power Source Detection
ACA Accessory charging adaptors 
HVDCP - High Voltage Dedicated Charging Port
INOV - Intelligent Negotiation for Optimal Voltage
PMIC - Power management integrated circuits
SoC - State of Charge (0 - 100%)
USBIF - USB Implementers Forum
USB - Universal Serial Bus 
USB PD - USB Power Delivery 
VOCC - Voltage Open Loop Multi-step Constant-Current Charging by Oppo.

Charging Stations
USB hardware - Wikipedia
Fast charge your iPhone - Apple Support
Galaxy Note8 - Identify the correct charger (SM-N950W) | Samsung Support CA Can You Use Any Charger With Any Device? | HowToGeek 2018
The best USB-C PD chargers of 2020 - CNET
How USB Charging Works, or How to Avoid Blowing Up Your Smartphone - ExtremeTech 2017
Speed, Thermal & Performance Comparison of Fast Charging Standards

What Is Fast Charging? |
USB charging
USB in tech