AS3955 NFC Interface Tag

NFC T2T to SPI/I2C Interface Tag IC


  • High sensitivity ISO14443A frontend
  • Tunneling and extended modes for high-speed bidirectional data transfer
  • Fully compliant to NFC Forum T2T standalone, T4T with ext. microcontroller & ISO 14443A
  • Energy harvesting up to 5mA@4.5V


  • Standalone NFC passive tag functionality
  • High endurance EEPROM memory reaches automotive grade quality
  • Allows batteryless designs
  • Fast system integration and high-speed data transfer

Product parameters

Frequency [MHz] 13.56
Protocol NFC Forum compliance and ISO 14443A compliance
Supply Voltage [V] RF field or ext. 1.65 to 5.5
Temperature Range [°C] -40 to +125
Interface ISO14443A \ SPI slave interface up to 5 Mbit/s \ I²C slave interface up to 1 Mbit/s
EEPROM [kbit] 4
Features Type 2 Tag \ Type 4 Tag emulation \ Passive wake-up interrupt \ 32-bit password memory protection \ Silent mode \ Energy harvesting 5mA @ 4.5V
Data Rate [kbit/s] 106
Package Die, MLPD-10, WL-CSP

General Description

AS3955 NFC dynamic tag IC is the ultimate solution to easily add NFC functionality to electronic devices, pair them with NFC phones and transfer data. Thanks to a high sensitivity ISO14443A front-end and integrated resonance capacitor, AS3955 offers standalone NFC passive tag functionality in a small footprint. Fast system integration and high speed data transfer are guaranteed by the available SPI and I²C interfaces and by optimized protocols (tunneling mode and extended mode), allowing bidirectional communication between the device microcontroller and an external NFC compliant device or ISO14443A reader device. AS3955 is able to operate fully powered by the RF field, without any external supply. This, combined with an advanced energy harvesting feature, greatly increases battery life time or even allows batteryless designs.

Not Recommended for New Designs
ams AG is discontinuing production of this device.

This product suits for the following applications:

  • Consumer electronics: Bluetooth, BLE and Wi-Fi pairing in consumer electronics
  • Home appliance: Configuration update over NFC
  • Retail: Interactive marketing
  • Enterprise: Access control and personal identification
  • Gaming: Interactive gaming
  • Automotive: Smart keys
  • Health care: Retrieve and update data over NFC
  • Maintenance: Log access and configuration update
  • Production: Power off configuration
  • Industrial and Internet of Things (IoT) exposed to harsh operating conditions and extreme temperatures
  • Products requiring an extended operating lifetime, such as HVAC equipment, medical and healthcare devices, wireless sensors for civil infrastructure
  • Mission-critical products that require a zero failure rate
  • Feature and biometric payment cards


Title Category Headline Buy
AS3955DemoKit Application Board Demo Kit for AS3955

Technical Documents

Type Description Language
Datasheet Document version 2-04 (AS3955A) English

Environmental Documents

Type Description Language
RoHS Certificate RoHS Certificate_AS3955 English


Type Description Language
EoL Notification AS3955A (issued 2019-Jan) English
Product Change Notification PCN34-2018 (AS3955A) English
Product Change Notification PCN24-2016 (AS3955) English

Other Information

Type Description Language
Block Diagram AS3955 Block Diagram English
Factsheet NFC Dynamic Tag IC English

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