The Secret Advantages of the Proximity Card T5577 Chip

The Secret Advantages of the Proximity Card T5577 Chip

by Mike Boehm on September 10, 2022

Access control has applications in nearly every industry. While security is at the forefront of any business's mind when talking about RFID cards, access control technology can expand a business’s capabilities in many ways. RFID cards can be used for punching in and out, logging employee behavior and movements, allowing customers to access private member-only areas, and much more. The T5577 chip is the best option for your business because of extra advantages that aren’t found in other proximity chips. Continue reading to learn more about the T5577 chip, and you might be able to use it in your business.

What is the T5577 Chip?

The T5577 chip is manufactured by Atmel under the name ATA5577 as a contactless Identification Integrated Chip (IDIC) with read and write capabilities. The T5577 comes in three different types, the M1, M2, and M3, which are compared below:



The T5577 chip operates on the 125 to 134 kHz frequency band, a low-frequency RFID band that can be used globally without a license. The T5577 chip is connected to a single coil that powers the chip and provides a bidirectional communication interface, forming a transponder or identification tag. The antenna sends and receives radio waves, and the chip’s integrated circuit modulates radio signals and processes data. 



Advantages of the T5577

The T5577 chip is an emulator chip that can be programmed to the most common ID card formats in use today. The T5577 can emulate cards that make use of the standard 26-bit Wiegand format. This format is most commonly used with H10301 cards. The T5577 can emulate the H10301 card format as well as the following 26-bit card formats:


  • HID 1326
  • ProxCard II
  • Indala
  • EM Cards
  • Kantech XSF
  • AWID 26-bit, 34-bit, 37-bit and 50-bit
  • Keri MS
  • Doorking DK Prox
  • H10302
  • Doorking DK Prox
  • DSX D10202
  • Farpointe Pyramid
  • Keyscan C15001 36-bit


Companies using the T5577 chip can rewrite the chip to match any of these card formats while still using the 26-bit Wiegand format. By reprogramming the chip, you change the way it represents itself or communicates with the reader so that it emulates one of the card formats above. Why choose one card format when you can enjoy the versatility of the T5577 and its 10 compatible card formats? For example, if a company needs two sets of RFID cards or fobs for different access control readers, they can use T5577 chip cards to emulate two different card types.


The only limitation is that the chip can only have one serial number at a time and can only operate in one mode at a time. If the chip type or serial number needs to change, it will need to be reprogrammed each time.

1. Cards, Keyfobs, Implants, and more

The T5577 chip is most commonly used in H10301 cards, like the popular and professional CR80, but can also be purchased as a keyfob, wristband, adhesive tags, or even an implant. A company can choose any of these preferred formats to standardize with and then distribute to the employees.

2. Uses the 26-bit Standard Wiegand Format

The card format tells an access control system how to interpret the data on a card. A reader reads the card information and relays it to the access system for verification. The 26-bit format is widely used within the industry, and most access control systems accept this card format.

When using the 26-bit Wiegand format, the card relays a series of 26 numbers in binary form. For example:




This binary number has 26 numbers (called bits) in binary form that the reader reads and changes to decimal form. The first and last bit are not used when determining the card number:




Bits 2 through 9 are used to designate an 8-bit (0-255) facility code:




And bits 10 through 25 are used to designate a 16-bit (0-65545) ID number:



3. How Many Users? How Many Facilities?

Because the ID number is 16-bit, that means there are 65,535 possible ID numbers that you can assign within your access control system. That is 65,535 unique employees. 


The facility code is added to provide a higher level of designation across a business. If two businesses merge, some employees may have the same ID number but should have different facility codes, so there are no issues authenticating who is requesting access. The 8-bit facility code means there are 255 possible facility codes.


Continuing the above example, the access control system will interpret the 26-bit card information into these two decimal numbers:


Facility Code – 186 (10111010)

ID Number – 26034 (0110010110110010)


The access control system knows that the employee assigned to ID number 26034 with facility code 186 is trying to enter the building or access secure areas. If this ID is valid within the access control system, the employee can then gain access to the building safely, securely, and efficiently. The total number of unique cards that can be assigned is 16,711,425. This is the huge benefit of using a chip, like the T5577, that makes use of the 26-bit standard format.

4. Other T5577 Features

Besides the 16 million unique ID codes that can be assigned using the standard 26-bit format and multiple different card types that can be used,


The T5577 Atmel chip is compatible with the Atmel T5557/ATA5567. In most applications, the T5577 can also effectively replace the Atmel E5551/T5551 card.


The T5577 has a total of 363 bits of integrated EEPROM memory across 11 blocks:

  • 7 x 32-bit blocks for user memory
  • 2 x 32-bit blocks for unique ID
  • 1 x 32-bit block for option register
  • 1 x 32-bit configuration register
  • 1 lock bit


Any ID card in the 125kHz range that is compatible with the T5577, like those listed earlier, can be cloned onto the T5577. RFID programming tools can be used to copy or clone the information from one RFID card onto the T5577 chip card. Once the T5577 chip card has the information of the original RFID card, it can open or access any areas that the original card could access. This can pose a security risk, but in most cases, it’s a useful feature that allows businesses to copy cards with ease and transfer ID numbers as needed.

T5577 Chip Use Cases

The T5577 can be used in RFID identification cards. Because the T5577 offers great encryption and stable performance, it is widely used across various industries, including education, transportation, healthcare, and hospitality. The T5577 is a proximity card meaning it communicates with a reader when placed in close proximity to the reader.


For example, the T5577 can be used in the following ID cards:


  • School access card (teachers and staff)
  • Gas card
  • Campus ID card
  • Health insurance card
  • Hotel room entry card
  • Attendance (Punch in/out) card
  • Club card
  • ID card to badge into secure areas
  • Supermarket membership card


The T5577 chip can also be implanted into your hand and configured for easy access into your home, car, or workplace. The first RFID microchip was implanted in 1998. Since then, the technology and possible use cases have expanded.

Things the T5577 Chip Can’t Do

1.   Communicate with NFC devices

Because the Atmel T5577 chip is low-frequency, it does not comply with the NFC standard. NFC standards operate on a high frequency (13.56MHz), meaning they are incompatible. The T5577 chip cannot communicate with NFC-capable devices, including smartphones and NFC readers.

2.   Make Payments

Since the addition of chips and PINs in credit and debit cards, paying with the cards has gotten much safer. EuroPay, Mastercard, and Visa can be shortened to EMV. EMV is the complex protocol for chip technology that includes certifications, standards, and corporate partnerships. The major payment networks have shown no interest in supporting and authorizing chip implants to be used to make payments. The technology is already there, but the industry is resistant to the idea. The T5577 chip is therefore unable to act as your debit or credit card.

3.   GPS Tracking

The current state of GPS tracking technology means that the RFID implantable chip cannot be used in this manner. GPS trackers are becoming smaller and more efficient but have still not reached the level that allows use in this form.