What is fast charge?

Three elements of fast charging

To achieve fast charging and charging functions on mobile phones, we need to meet three elements, and the three are indispensable. Charger, battery, charge IC. The charger needs to satisfy enough output current and voltage, because the charger has a large parasitic resistance, if you want to achieve a larger charging current, the charger needs a higher on-load output voltage.

Main principle of fast charging

From the physical calculation formula, power (P) = voltage (U) x current (I), in the case of a certain amount of battery power, power marks the charging speed, then there will be three ways to shorten the charging time:

First, the voltage is constant and the current is increased.

Two, the current is constant and the voltage is raised.

Three, voltage and current increase.

At present, mobile phone fast charging technology can be divided into two main categories: low voltage fast charging and high voltage fast charging. There are two ways to solve this problem: one is to use large capacity batteries directly, and the other is to use fast charging technology.

There are four main fast charging technologies for mobile phones: VOOC flash charging (OPPO charging 5 minutes call 2 hours fast charging technology), Samsung Fast Charge fast charging technology, Qualcomm Quick Charge fast charging technology, MediaTek Pump Express fast charging technology.

1.OPPO VOOC flash charging fast charging technology

VOOC flashlight charging for 5 minutes to talk for 2 hours, charging 30 minutes can charge the phone from 0% to 75%.

There are two main ways to increase charging speed: one is to raise the voltage, the other is to increase the current by two. Increasing the voltage will increase the calorific value during the charging process, accelerate the aging of the battery and may bring potential safety hazards, so the actual effect is not good. In contrast, raising the current is more realistic.

VOOC flash charging technology adopts low voltage and high current mode to ensure the safety during charging.

2. Qualcomm's Quick Charge fast charging technology

QC1.0: voltage and current rise to 5V2A, charging time reduced by 40%

Time goes on, big-screen smartphones start to explode, battery life can not keep up, fast charging has become a manufacturer to enhance the user experience of one of the magic weapons, so QC2.0 was born.

QC2.0: Compared with the old standard, QC2.0 changed the charging voltage epoch-making, from maintaining the conventional 5V for many years to 9V/12V/20V, maintained the same 2A current with QC1.0 to achieve 18W high-power transmission, and wires can be used without special treatment of old wires.

By increasing the voltage, the power goes up, but the efficiency decreases. With each increase in voltage, efficiency drops by about 10%, and most of this energy is converted to heat, so the 20V voltage range is almost useless, leaving only 5V, 9V, and 12V. Even if it's still hot, Qualcomm feels that 5V to 9V strides are too big, a bit of an egg, so it can continuously adjust in 0.2V units until it finds the most suitable voltage, what voltage is the most appropriate? Qualcomm has its own unique voltage intelligent negotiation (INOV) algorithm, which is QC 3.0.

QC3.0: On the basis of QC2.09V/12V two-gear voltage, further subdivide the voltage range, using a unique INOV algorithm, with 200mV as a set voltage, the lowest can be down to 3.6V maximum voltage 20V, and downward compatible with QC2.0. With the full use of the Type-c interface instead of the original MicroUSB interface, the maximum current is also increased to 3A, because the voltage is lower so the efficiency is increased up to 38%, charging speed is increased by 27%, heating is reduced by 45%.

QC3.0 is good, but Google does not agree, you Qualcomm alone to do a set of how good, with my system must give me a USB PD protocol, the arm can not twist thigh, Qualcomm soft, and launched QC4.0.

QC4.0: increase power to 28W again and add USB PD support. The 12V voltage shift is cancelled, the 5V maximum output is 5.6A, the 9V maximum output is 3A, and the voltage shift continues to be subdivided into 20mV.

2.Fast Charge fast charging technology

Samsung's Fast Charge solution is the same thing as Qualcomm's Quick Charge 2.0, but only for Galaxy S6 and S6 Edge's Exynos chips.

3. Pump Express fast charging technology of MediaTek

Pump Express, a new fast charging technology for MediaTek, is built in PMIC's power management IC. The charger is allowed to determine the initial voltage required for charging according to the current. The PMIC sends out a pulse current command to the charger through the USB Vbus. The charger adjusts the output voltage according to this command, and the voltage gradually increases up to 5V to reach the maximum charging current.

In addition, whether there is any relationship between fast charging and data lines, the answer is yes. Because, charging inside the cell phone, the speed of cell phone charging depends on the size of the current and the size of the load. Simply speaking about the conditions that affect the current, AC, switching power supply, data line resistance, cell phone charging circuit DC, battery protector, battery, each of these links are the reasons that affect the charging current. Apart from other problems, the conductor material of wire diameter has a great influence on current. Good and poor wires are resistance in themselves, while poor wires have to lead to increased resistance and reduced current passing through them. It also causes the rate of cell phone charging down.

Shenzhen Xinyuxin Electronics Co., Ltd. is a professional manufacturer of R&D, production and sales (all kinds of communication equipment, high-definition equipment, computer network and other cables, connectors and peripheral electronic products), serving as one; PVC, wire drawing, processing chain.

The company has excellent professional research and development team and excellent management organization, in line with the "honesty-based, excellent quality, customer satisfaction" business philosophy, ISO-9001 quality