PCIF0 datasheet(197/294 Pages) ATMEL

Nome de Peças	PCIF0

Descrição Electrónicos	High Performance, Low Power Atmel AVR 8-bit Microcontroller Advanced RISC Architecture

PDF	294 Pages

Scroll/Zoom	100%

Fabricante Electrônico	ATMEL [ATMEL Corporation]

Página de início	http://www.atmel.com

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197 / 294 page

197

9219A–RFID–01/11

Atmel ATA5505 [Preliminary]

16.8

Driver (DRV)

The driver supplies the antenna coil with the appropriate energy. The circuit consists of two

independent output stages. These output stages can be operated in two different modes. In

common mode, the outputs of the stages are in phase; in this mode the outputs can be inter-

connected to achieve high-current output capability. The output voltages are in anti-phase

when using the differential mode; the antenna coil is thus driven with a higher voltage. For a

specific magnetic field, the antenna coil impedance is higher for the differential mode.

Because higher coil impedance results in better system sensitivity, the differential mode

should be given preference.

The CFE input is intended for writing data to a read/write or a crypto transponder. This is done

by interrupting the RF field with short gaps. The various functions are controlled by the MS and

CFE inputs (see Table 16-3 on page 198). The equivalent circuit of the driver is shown in Fig-

ure 16-1 on page 191.

Figure 16-10. Equivalent Circuit of Pin MS

Figure 16-11. Equivalent Circuit of Pin CFE

30µA

CFE

30 µA

PCIF0 Folha de dados(PDF) 197 Page - ATMEL Corporation