Samsung is one of the biggest proponents of wireless charging technology in the smartphone industry. The company has implemented various wireless charging standards in its flagship smartphones and accessories over the years.
Qi Wireless Charging
Qi (pronounced “chee”) is an open interface standard developed by the Wireless Power Consortium (WPC) for inductive electrical power transfer over distances up to 4 cm. The technology uses electromagnetic induction between transmitter and receiver coils to transfer power wirelessly.
Key features of Qi wireless charging:
- Transmitter (charging pad) and receiver (mobile device) contain copper coils
- Electric current passed through transmitter coil generates oscillating magnetic field
- Receiver coil converts magnetic energy back into electric current to charge device battery
- Operates at resonant frequency between 100-205 kHz
- Transfers power up to 5W for smartphones
- Distance between coils typically < 4 cm
Qi was first launched in 2008 and has become the most widely adopted industry standard for wireless charging. Samsung was one of the early adopters of this standard, introducing Qi compatibility starting with the Galaxy S3 in 2012.
All recent Samsung flagship smartphones support Qi wireless charging up to 9W or 15W. Samsung has also launched various Qi-certified wireless charging pads and stands over the years, including:
- EP-P1100 Wireless Charging Pad
- EP-P5000 Wireless Charging Stand
- EP-N5100 Wireless Charging Pad
- EP-N6100 Fast Wireless Charging Stand
PMA Wireless Charging
The Power Matters Alliance (PMA) standard was developed as an alternative to Qi wireless charging. The technology works on similar principles as Qi, using inductive energy transfer between transmitter and receiver coils.
Key features of PMA wireless charging:
- Operates at 277-357 kHz frequency range
- Can transfer higher power – up to 50W
- Uses larger transmitter coils for better alignment flexibility
- Implemented in Starbucks and McDonald’s chargers in the US
The PMA standard was adopted by Samsung for some of its smartphones between 2014-2017, including Galaxy S6, S7 and S8 models. These devices supported both Qi and PMA wireless charging. However, Samsung has moved away from PMA in recent years.
Samsung Fast Charge Wireless Charging
In addition to the open standards like Qi and PMA, Samsung has also developed its own proprietary wireless charging protocols to enable faster charging speeds.
WPC Faste Wireless Charging
This was Samsung’s first attempt at fast wireless charging, introduced with the Galaxy S6 in 2015. It was based on an extended proprietary protocol developed by Samsung and compatible accessories to provide up to 1.4 times faster wireless charging than standard Qi.
Key features of WPC Fast Wireless Charging:
- Based on modified Qi protocol
- 1.4x faster than standard 5W Qi wireless charging
- Compatible accessories include Fast Charge Wireless Charging Pad
- Supported by Galaxy S6 and S6 Edge+
Samsung Fast Charge Wireless Charging
Introduced in 2017 with the Galaxy S8 and S8+, this proprietary protocol delivered even faster wireless charging speeds up to 1.4 times that of the previous WPC Fast Wireless Charging standard.
Key features of Samsung Fast Charge Wireless Charging:
- Uses Samsung’s proprietary inductive charging technology
- 1.4x faster than WPC Fast Wireless Charging
- Compatible accessories include Fast Charge Wireless Charging Stand
- Implemented in Galaxy S8/S8+ and later models
Super Fast Wireless Charging
This is the latest and fastest wireless charging solution developed by Samsung, introduced with the Galaxy S10 in 2019. It can charge compatible devices up to 1.7 times faster than standard wireless charging.
Key features of Super Fast Wireless Charging:
- Based on Samsung’s advanced wireless power transfer technology
- Up to 1.7x faster than Fast Wireless Charging
- 12W power delivery vs 7.5W for Fast Wireless Charging
- Implemented in Galaxy S10, S20, S21, Note 10, Note 20 series
- Compatible accessories include Wireless Charger Duo Pad
Comparison Between Standards
Here is a quick comparison of the different charging standards supported by Samsung devices:
| Standard | Speed | Frequency | Distance | Power |
|---|---|---|---|---|
| Qi Wireless Charging | Standard wireless | 100-205 kHz | < 4 cm | 5W |
| PMA Wireless Charging | Standard wireless | 277-357 kHz | < 4 cm | 5W |
| WPC Fast Wireless Charging | 1.4x faster than Qi | 100-205kHz | < 4 cm | 7W |
| Samsung Fast Charge Wireless Charging | 1.4x faster than WPC | Proprietary | < 4 cm | 9W |
| Super Fast Wireless Charging | 1.7x faster than Fast Charge | Proprietary | < 4 cm | 12W |
In summary:
- Qi and PMA follow open global standards for up to 5W charging
- Samsung’s proprietary protocols offer faster wireless charging up to 12W
- Higher transfer speeds achieved by improving coil designs and power transfer efficiency
Compatibility Between Standards
There are some key points to note regarding compatibility between these wireless charging standards:
- Qi chargers are compatible with PMA receivers and vice versa
- However, Samsung’s proprietary fast charging won’t work on non-Samsung Qi or PMA chargers
- Similarly, third-party Qi chargers cannot fast charge recent Samsung phones
- For fast wireless charging, Samsung devices need compatible Samsung-certified chargers
- Older Samsung phones support both Qi and PMA in addition to Samsung’s own protocols
- Newer models support Qi and Samsung’s fast charging only
So in summary, for fastest wireless charging speeds, Samsung devices need to use Samsung-specific charging pads or stands.
Benefits of Wireless Charging
Wireless charging offers various benefits over traditional wired charging methods. Some key advantages are:
- Convenience – No need to plug and unplug cables
- Reduced wear and tear – Avoid strain on charging ports
- Flexibility – Charge anywhere on a compatible pad
- Waterproofing – No exposed ports susceptible to water damage
- Spatial freedom – Can be used while device is in use
- Aesthetics – Clean look without cables
For consumers, wireless charging delivers a simpler and more intuitive charging experience. It also enables sleek and port-free smartphone designs. The technology helps maintain device water resistance and durability over long-term use.
However, wireless charging has tradeoffs as well. It is slower than wired fast charging in most cases and less power efficient. The position of devices on charging pads can heavily impact power transfer efficiency. Costs of wireless chargers remain higher compared to wired alternatives.
How Wireless Charging Works
Wireless chargers use electromagnetic induction to transmit power between two coils – a transmitter coil in the charger and receiver coil in the device being charged. An alternating current is passed through the transmitter coil, generating an oscillating magnetic field.
When a device with a built-in receiver coil is placed on the charging pad, it experiences the magnetic flux from the transmitter coil and a current is induced in the receiver. This electrical energy is used to charge the device’s battery.
Electromagnetic induction works wirelessly over short distances of up to 4 cm. The technology is safe and does not expose users to electromagnetic fields like microwave radiation. However, metal objects between the transmitter and receiver can interfere with power transfer.
For effective charging, the device needs to be properly aligned on the wireless charger so that the inductive coils are oriented parallel to each other. Some chargers have multiple overlapping coils to provide positional flexibility.
Resonance for Improved Efficiency
Modern wireless chargers use resonant inductive coupling for higher power transfer efficiency compared to traditional inductive methods. This involves tuning the transmitter coil to resonate at a specific high frequency.
The receiver coil is also tuned to the same resonant frequency, enabling efficient energy transfer in the near-field region between the coils. The use of magnetic resonance allows power transmission of 5W or more over a distance up to 5mm with efficiency of around 70-80%.
Frequency Standards
Commonly used frequency ranges for resonant wireless charging include:
- 110-205 kHz – Used by Qi and Samsung wireless charging
- 277-357 kHz – Used by PMA wireless charging
- 670 kHz – Proposed for next-gen Qi charging
Higher frequencies allow faster charging at the cost of reduced coil efficiency and energy losses. Frequencies below 100 kHz are inefficient for power transfer over larger gaps.
Power Transmission
Standard wireless charging provides power delivery of 5W or less, which is suitable for slow overnight charging. For faster wireless charging, transmission power needs to be increased.
Qi can support up to 15W fast charging while PMA goes up to 50W. Samsung’s latest Super Fast Wireless Charging provides up to 12W power transfer.
However, higher power exacerbates energy losses in the form of heat. This can reduce charging efficiency and lead to device overheating. Advanced coil materials and circuit designs are used to counteract these effects.
Future Advancements
Future generations of wireless charging technology will focus on improving charging speed, efficiency, and range. Some emerging techniques include:
- Magnetic resonance coupling
- Parasitic power transfer
- Optical wireless charging
- Ultrasonic wireless charging
Long range wireless charging of up to several meters is currently restricted to low power applications. But mid-range solutions capable of charging phones from feet away could become viable in the next few years.
Samsung Wireless Charging Coils and Circuits
Samsung uses advanced coil and circuit designs in its devices to optimize wireless power reception and charging speed.
Receiver Coils
The receiver coil in Samsung phones is typically around 40mm diameter. It comprises several tightly wound turns of thin enamel coated wire, e.g. 0.08-0.1mm thickness.
Litz wire made of many thinner enameled strands can minimize power losses at high frequencies. Ferrite shields are placed below coils to focus magnetic flux towards the transmitter.
Multiple receiver coils are sometimes used to provide positional flexibility and avoid dead spots. All these coils connect to the charging circuitry and power management IC.
Charging Circuit
The wireless charging circuitry in Samsung phones converts current from the receiver coil into a steady DC output voltage to charge the battery. It consists of components like:
- Rectifiers – Convert AC into DC
- Capacitors – Filter/smooth output voltage
- Regulators – Maintain steady voltage for battery
- Controllers – Regulate charging current and voltage
Higher rated components are used to handle the power levels required for fast wireless charging. State-of-the-art fabrication techniques like flexible PCBs allow compact coil and circuit implementation.
Power Management Integrated Circuits
Dedicated power management ICs (PMICs) are used to regulate the wireless charging process. These chips provide capabilities like:
- Switching regulators to step-down DC voltage for battery
- Programmable charging current control loops
- Multi-mode battery voltage regulation
- Over-voltage, under-voltage, and over-current protection
- Foreign object detection capability
- Communication with wireless charging system
For example, Qualcomm’s latest SMB1396 PMIC supports programmable output voltage and current tailored to battery needs. It integrates safety features and 15W fast charging support.
Samsung’s Wireless PowerShare Feature
Selected Samsung phones support a unique reverse wireless charging feature called Wireless PowerShare. This allows users to charge compatible devices such as phones, watches or earbuds by simply placing them on the phone’s back.
PowerShare uses the phone’s battery to wirelessly charge devices with lower power requirements. It enables helpful charging scenarios when conventional power sources are unavailable.
How PowerShare Works
PowerShare leverages the wireless charging coils and PMIC built into Samsung phones to function as both receiver and transmitter.
Phones like the Galaxy S10 use an increased 4,500mAh battery capacity. The PMIC enables safe two-way charging at up to 9W power delivery.
authenticated devices placed on the phone back experience the same electromagnetic inductive charging process as when using a wireless charger.
Compatible accessories connect via NFC for authentication before charging begins. The phone displays the connected device’s battery status.
Compatible Devices
The list of devices compatible with Wireless PowerShare includes:
- Samsung Galaxy Buds/Buds Pro
- Samsung Galaxy Watch 3/4
- Samsung Galaxy S and Note phones
- AirPods Pro/AirPods Max (non-Samsung devices)
- Other Qi-compatible phones and accessories
Non-Samsung Qi devices can also be charged but may exhibit slower top-up speeds due to lack of optimization.
Usage Tips
To use PowerShare efficiently:
- Update both the transmitting and receiving devices
- Turn on NFC and wireless charging options on both devices
- Align devices properly back-to-back for best power transfer
- Avoid cases or covers that may interfere with charging
- Check battery levels to prevent excessive discharge
PowerShare provides additional flexibility but should be used judiciously to avoid draining the phone’s own battery.
Safety Mechanisms in Wireless Charging
Samsung employs various mechanisms in its devices and chargers to ensure efficient and safe wireless charging experience.
Output Power Regulation
PMICs in Samsung devices dynamically regulate power drawn from chargers during wireless charging. This avoids overheating or damage by preventing overcurrent or excessive voltage conditions.
As charging nears completion and battery voltage saturates, charging power and current are reduced. Strict voltage and current limits are maintained for safety.
Overheat Protection
Temperature sensors measure the heat of receiver coils and other internal components during wireless charging. The PMIC cuts off charging if temperatures rise above safe thresholds to prevent component damage.
External phone and charger temperatures are also monitored. Fans built into charging stands actively cool down devices if required.
Metallic Object Detection
Wireless chargers use proprietary object detection techniques to identify presence of metallic particles like coins or keys. This avoids risks of metal heating due to eddy current induction.
If metal objects are detected, the charger may halt charging and display an alert notification for the user to remove them.
Frequency Splitting
Samsung chargers that support multiple devices use frequency splitting to minimize interference. Each device is assigned a unique coil excitation frequency for simultaneous charging.
This avoids crosstalk between coils in close proximity that can lead to reduced charging speeds and efficiency.
Child Safety
Newer Samsung wireless chargers automatically suspend charging if they detect the weight of a child climbing or standing on them. This prevents risks of injuries.
Charging resumes once the unintended additional weight is removed. This showcases how Samsung prioritizes consumer safety.
Diagnosing Wireless Charging Issues
In some cases, Samsung devices may fail to wireless charge reliably. Here are some steps to diagnose common wireless charging problems:
Check Compatibility
- Confirm charger and device support the same standard – Qi, PMA or Samsung’s own protocols.
- Use Samsung-certified chargers for fastest charging on Samsung phones.
- See if other Qi/PMA phones can charge on the pad. If yes, compatibility is not the issue.
Examine Charging Status
- Check if charging indicator displays on phone screen while docked.
- Inspect charger status lights – flashing or off may indicate a foreign object or misalignment.
- Does charger surface or phone heat up while attempting charging? If no, coil coupling issue likely.
Try Different Locations
- Try repositioning the device slightly – proper coil alignment is needed.
- Verify no obstructions between device and charging surface.
- Test charging on different pads – issue could be with one charger.
Inspect Device Ports and Battery
- Check for debris in charging port – can impact wireless charging sensors.
- Examine battery capacity and wear levels using diagnostic tools.
- Worn out batteries may have reduced ability to hold wireless charge.
Update Phone and Charger Firmware
- Use latest phone operating system and wireless charger firmware.
- Updates improve charging compatibility and performance issues.
Factory Reset Charger
- Reset the charger to clear out any software glitches.
- Refer to charger manual for resetting procedure.
Contact Samsung Support
- If above steps don’t fix the problem, contact Samsung support or take device in for service.
- Hardware defects with receiver coil or charging IC may require repair/replacement.
Thorough troubleshooting helps identify and resolve wireless charging difficulties.
Wireless Charging Precautions
While generally safe, some basic precautions should be kept in mind when using wireless chargers:
- Don’t use chargers with damaged wires or plugs which can cause electric shocks.
- Avoid charging on metallic surfaces which can get heated.
- Prevent contact with liquids which can lead to electrocution.
- Don’t attempt to charge when hearing aids or medical devices like pacemakers are present.
- Don’t charge while device or charger is wet to avoid potential damage.
- Don’t stack multiple wireless charging devices to prevent overheating.
- Avoid covering charger or device as it can trap heat.
- Don’t charge bombers, inflammables or explosives due to risks.
Adherence to these simple guidelines ensures an optimal and hazard-free wireless charging experience.
