# T5577 125 kHz RFID card: specs

> Passive low-frequency RFID card with a rewritable chip. Data sheet used: Microchip (Atmel) ATA5577C, which is compatible with the T5557 and ATA5567.…

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Passive low-frequency RFID card with a rewritable chip. Data sheet used: Microchip (Atmel) ATA5577C, which is compatible with the T5557 and ATA5567. The card needs a writer to change its contents.

Every value cites its sourcePinout not published

[Buy on Compoden](https://compoden.com/products/125khz-writable-rfid-t5557-t5567-t5577-rewritable-proximity-card-for-id-writer-copier-duplicate-thin-card)

## Specs

| Spec | Value | Source |
|---|---|---|
| RF frequency | 100 kHz to 150 kHz (125 kHz and 134 kHz applications) | source Features (p.1); Section 1 Introduction |
| Memory | 363 bits EEPROM: 11 blocks of 32 bits plus 1 lock bit each | source Features (p.1) |
| User memory | 7 blocks of 32 bits including the 32-bit password block; 2 blocks hold the unique ID | source Features (p.1) |
| Coding options | Manchester, bi-phase, FSK, PSK, NRZ; data rate RF/2 to RF/128 | source Features (p.1) |
| Modes | Basic Mode or Extended Mode; password mode; answer-on-request mode | source Features (p.1) |
| Write protection | One lock bit per block; once locked the block cannot be written again | source Section 4 Functional Blocks, memory description |
| Operating ambient temperature | -40 C to +85 C | source Section 8 Absolute Maximum Ratings |
| Write endurance | 100000 cycles (erase all / write all) | source Section 9 Electrical Characteristics, item 9 |
| Maximum coil current | 20 mA DC or AC peak at 125 kHz | source Section 8 Absolute Maximum Ratings |

## Power

| | Value | Source |
|---|---|---|
| Supply | Passive card, powered through its coil by the reader at 100-150 kHz | source Section 9 Electrical Characteristics, item 2.2 |
| Current | Read: 2 uA typical, 5 uA max (chip supply current, full temperature range) | source Section 9 Electrical Characteristics, item 2.2 |

## Pinout
We don't publish a pin table for this part: no official source we could verify gives one. Check the labels printed on your module, and see the notes below.

A card has no header or pins. The sheet is the ATA5577C chip; which of T5557, T5567 or T5577 is on the supplied cards is not documented by a maker source.

## Build with it
Project ideas for the T5577 125 kHz RFID card. Each link opens Soldr with the prompt filled in; Soldr assigns the pins, checks power and shows how to wire every part.

- [Card read demo on a Raspberry Pi](https://app.soldr.ai/?prompt=I%20want%20to%20build%20a%20card%20reading%20demo%20with%20a%20Raspberry%20Pi%205%2C%20a%20125%20kHz%20USB%20reader%20and%20a%20writable%20125%20kHz%20card%20that%20shows%20the%20card%20ID%20on%20screen): Needs a 125 kHz reader, which is the JT308 here. The card must first be written by a 125 kHz writer you already own so it sends an ID the reader understands.
- [Visitor sign-in table with notice](https://app.soldr.ai/?prompt=I%20want%20to%20build%20a%20sign-in%20table%20with%20a%20Raspberry%20Pi%20Zero%202%20W%2C%20a%20125%20kHz%20USB%20reader%2C%20writable%20125%20kHz%20cards%20and%20an%20OLED%20showing%20the%20last%20card%20ID): If it records who signs in, display a notice and get agreement. Cards are blank until written with a writer you already own.
- [Timed card tap clock](https://app.soldr.ai/?prompt=I%20want%20to%20build%20a%20card%20tap%20clock%20with%20a%20Raspberry%20Pi%204%2C%20a%20125%20kHz%20USB%20reader%2C%20a%20DS3231%20clock%20module%20and%20writable%20125%20kHz%20cards): Learning project. Only use cards you own and tell anyone whose taps are recorded.

## Common mistakes

- Locking a block by accident: the lock bit is permanent for that block ([source](https://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-9187-RFID-ATA5577C_Datasheet.pdf))
- Using a 13.56 MHz reader such as the MFRC522: this chip works at 100-150 kHz only ([source](https://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-9187-RFID-ATA5577C_Datasheet.pdf))
- Setting password mode and losing the password: in password mode the first 32 bits after the opcode are taken as the password ([source](https://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-9187-RFID-ATA5577C_Datasheet.pdf))

## Not covered by the official source

- Which chip (T5557, T5567 or T5577) is in the supplied cards is not documented by a maker source.
- The reader's output format is not covered here; check the reader's own page.

## Sources

- [link](https://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-9187-RFID-ATA5577C_Datasheet.pdf) (Microchip/Atmel 9187H-RFID-07/14, ATA5577C Read/Write LF RFID IDIC 100 to 150 kHz)