T5557 Datasheet, PDF (2/30 Pages) ATMEL Corporation – Multifunctional 330-bit Read/Write RF-Identification IC

T5557 –
Building Blocks
Figure 2. Block Diagram
Coil 1
*
Coil 2
* Mask option
Modulator
Mode register
Controller
Test logic
POR
Memory
(330 bit EEPROM)
Input register
HV generator
Analog Front End (AFE)
The AFE includes all circuits which are directly connected to the coil. It generates the
IC’s power supply and handles the bi-directional data communication with the reader. It
consists of the following blocks:
• Rectifier to generate a DC supply voltage from the AC coil voltage
• Clock extractor
• Switchable load between Coil 1/Coil 2 for data transmission from tag to the reader
• Field gap detector for data transmission from the base station to the tag
• ESD protection circuitry
Data-rate Generator
The data rate is binary programmable to operate at any data rate between RF/2 and
RF/128 or equal to any of the fixed e5550/e5551 and T5554 bitrates (RF/8, RF/16,
RF/32, RF/40, RF/50, RF/64, RF/100 and RF/128).
Write Decoder
This function decodes the write gaps and verifies the validity of the data stream
according to the Atmel e555x write method (pulse interval encoding).
HV Generator
This on-chip charge pump circuit generates the high voltage required for programming
of the EEPROM.
DC Supply
Power is externally supplied to the IDIC via the two coil connections. The IC rectifies and
regulates this RF source and uses it to generate its supply voltage.
2 T5557
4517E–RFID–02/03