The world's Smallest 13.56 MHz Wireless Charging LSI "ML7630/7631"

13.56MHz (NFC) Wireless Charging Makes It Possible

Advantages of 13.56 MHz (NFC) Wireless Charging
for Compact Device under 200mW

13.56MHz Wireless charging system
implementation image 13.56MHz Wireless charging system
implementation image

Save the space for charging
"No constraints on design" of devices

Compared to the charging from a USB connector, the conventional charging method for compact devices such as wearables, the wireless charging system equipped with LAPIS Semiconductor's 13.56 MHz (NFC) wireless charging chip set, "ML7630/7631", can save the space for charging function.
Using an ultra-compact antenna as well as an antenna for NFC communication simultaneously can reduce the implementation area down to "about 50%" for compact cube antenna, and "about 75%" for a flexible antenna.
When compared to other charging systems, the 13.56 MHz (NFC) wireless charging that can use ultra compact antennas offers more "compact implementation".

Wireless Charging Makes Wearable Device
"Completely Water-Proof"

Wearable device, headset, earphone
Expected to be used in underwater or waterfront

Water-proof cap or USB connector to protect the contacts and components required to charge the conventional devices from water, along with applicable designs and design limitations are no longer needed for the wireless charging.

Non-contact wireless charging makes the design and BOM (Bill of Materials) simple.

The NFC Tag function (NFC Forum Type3 Tag), a prerequisite for wearable device, is also incorporated. Integrating the wireless charging and the NFC Tag function into one single chip also reduces the BOM cost.

ML7630 / 7631 NFC Forum Type3 Tag function

Mechanism of Wireless Charging and Charge Capability

Mechanism of 13.56 MHz (NFC) Wireless Charging

The 13.56 MHz (NFC) wireless charging LSI, "ML7630/7631", uses the electromagnetic induction method to supply power through 13.56 MHz magnetic fields.

The electromagnetic induction method supplies power by using two coils as "oscillator", at power transmitter and receiver. Place these coils face-to-face with one coil being connected to the charging and the other coil being received the power.

13.56MHz (NFC) is Capable of Detecting Foreign Object as IC Card

Regardless of its method, the existing wireless charging system can damage the data, if any IC card including credit card or electronic money exists in proximity while strong power is supplied.
13.56 MHz (NFC) wireless charging can reduce the potential risk of damaging data because it detects foreign object in the IC card easily as it uses the same resonance frequency as the IC card.

Mechanism of 13.56 MHz (NFC) Wireless Charging

How about charge capability?

Comparison of "charging time to 90 % of the battery capacity" between USB charge and 13.56 MHz wireless charging 1C charge*

*1C charge : Charging with the same amount of electric current as the discharge capacity of battery for an hour

Comparison of " charging time to 90 % of the battery capacity " between USB charge and 13.56 MHz wireless charging 1C charge

When the battery capacity is within 50 mAh,
13.56 MHz wireless charging and USB cable show "almost the same charging time".

Expected devices with the battery capacity within 50mAh are
wearable device, Bluetooth® headset, wireless earphone, etc.

Devices with the battery capacity within 50mAh

Specifications

"ML7630" 13.56MHz (NFC) power receiver LSI

Product name

ML7630

Data Flash

1K Byte

Operating Frequency

13.56MHz

Power Supply

Generate from magnetic fields

I/F

NFC Forum Type3 Tag v1.0

I2C slave × 1ch

Charging Control

Power receiver/ rectifier/power charging voltage output

ADC (Method)

10bit (SA type)

Operating Temperature

- 40°C to + 85°C

Package

WL-CSP 34 pin

2.6mm × 2.6mm 0.4mm pitch

LAPIS Semiconductor's WL-CSP36

Power receiver and Tag function integrated in one chip

  • 200mW LDO output
  • Wireless charging protocol auto-run
  • Monitoring electric current, voltage, temperature (A/D converter, comparator)
  • NFC Forum Type3 Tag

"ML7631" 13.56MHz (NFC) power transmitter LSI

Product name

ML7631

Data Flash

1K Byte

Operating Frequency

13.56MHz

Operating Frequency

5V

I/F

I2C slave × 1ch

Operating Temperature

- 40°C to + 85°C

Package

WQFN 32 pin

5.0mm × 5.0mm 0.5mm pitch

LAPIS Semiconductor's WL-CSP36

One single chip can contain all the functions necessary for power transmission

  • Wireless charging protocol auto-run
  • Transmitter output level setting
  • Detection of the dropout of the power receiver device
  • Detection of foreign object between power transmitter and receiver

Evaluation

Data sheet

Other documents can be downloaded from the technical information site for engineers.

LSI sample

Distribution expected to start
in May 2018

Please inquire
Reference board

Distribution expected to start in June 2018

Please inquire
13.56 MHz (NFC) Wireless Charging Chip Set Technical Information Site for Engineers Inquiries about 13.56 MHz (NFC) Wireless Charging Chip Set
lineup for 13.56 MHz (NFC) wireless charging chip set LAPIS Semiconductor Products

* The name of company and product name are generally a trademark or registered trademark.