Low-frequency credentials
T5577 programmable cards & fobs
Re-programmable 125 kHz cards and key fobs on the Atmel/Microchip T5577 chip — the multi-format workhorse that can be configured to behave as EM, HID Prox, AWID, Indala and other low-frequency protocols. Supplied blank for locksmiths and integrators with their own programmers, or pre-programmed by us to your format and number range.
Available as a compatible-by-specification credential after we verify your reader and facility format.
What is a T5577 card?
A T5577 card carries the Atmel/Microchip T5577 chip — a re-programmable 125 kHz transponder whose modulation and data can be configured to behave like EM4100, HID Prox, AWID, Indala and other low-frequency protocols. Locksmiths and integrators use T5577 stock as a universal blank for low-frequency work. American Key Cards supplies T5577 cards and fobs blank, or pre-programmed to your format and number range.
Overview
About T5577 programmable
One chip, most of the 125 kHz world. The T5577 is the re-programmable transponder behind nearly every "universal" low-frequency card: set its configuration block and it answers a reader like an EM card, an HID Prox card, an AWID or an Indala. That flexibility is why locksmiths, integrators and access-control service companies keep it on the shelf instead of stocking a separate blank for every format they might meet this week.
We supply T5577 stock two ways. Blank, by the box, for shops running their own cloners and programmers. Or pre-programmed: tell us the protocol, facility code and number range your panel expects, and cards arrive ready to enroll — the same service we offer on every open prox format we carry.
Technical details
T5577 programmable cards & fobs specifications
- Frequency
- 125 kHz
- Chip
- T5577 (Atmel / Microchip Technology)
- Memory
- 363 bits EEPROM in 7 user blocks of 32 bits, plus configuration block
- Emulates
- EM4100/4102/4200, HID Prox, AWID, Indala, Farpointe and other 125 kHz protocols
- Modulation
- Configurable — FSK, PSK, Manchester, Biphase, NRZ
- Protection
- Optional password mode and per-block lock bits
- Card dimensions
- CR80 ISO/IEC 7810 ID-1 — 85.6 × 54 mm, 30 mil / 0.76 mm (ISO body)
- Printing
- ISO body runs through dye-sub direct-to-card printers
Available configuration
Choose the form factor after the technology
Where it fits
Common T5577 programmable applications
Locksmiths & key shops
Universal blank stock for on-the-spot duplication of open 125 kHz fobs and cards customers bring in.
Integrators & service companies
One SKU that covers most low-frequency service calls, programmed on site to whatever the panel needs.
Property managers
Pre-programmed replacement credentials for buildings running mixed or undocumented legacy prox systems.
Access-control testing
Configurable credentials for commissioning readers and verifying formats before a bulk order.
Before you order
How to order T5577 programmable correctly
- Low-frequency only
A T5577 emulates 125 kHz protocols. It cannot emulate 13.56 MHz smart cards — MIFARE, DESFire and iCLASS are a different technology and, when secured, cannot be reproduced by anyone.
- Blank or configured
Blank stock assumes you have a programmer. If you do not, order pre-programmed: we verify the target protocol from a sample or reader model and encode before shipping.
- Lock bits are permanent
T5577 blocks can be locked during programming. Locked pages cannot be reused, so plan your configuration before committing large batches.
Compatibility reference
Find your exact reader format
Choose the matching format before ordering. These pages list the relevant reader families, OEM references and credential requirements.
Questions we actually get
T5577 programmable FAQ
Which formats can a T5577 be programmed to?
The common open 125 kHz families: EM4100/4102/4200, HID Prox (26-bit H10301 and related open formats), AWID, Indala, Farpointe and most other low-frequency protocols. It configures its modulation — FSK, PSK, Manchester, Biphase — to match the target system.
Do you sell T5577 stock blank?
Yes — ISO cards, clamshells and fobs by the box for shops with their own programmers. We also pre-program to your format and number range if you would rather receive credentials ready to enroll.
Is a T5577 card as reliable as a factory-programmed card?
For day-to-day use, yes — it is the same passive 125 kHz technology. For large permanent deployments we usually recommend factory-programmed single-format stock, which removes the risk of a mis-configured block; T5577 shines for service work, mixed estates and small batches.
Need help identifying the technology?
Send a photo of the credential and the reader model. We'll identify the format before we quote a compatible product.
Lifetime parts & workmanship guarantee on every card