3

4591B–RFID–09/05

U9280M-H

Table 2-1.

Pin Description

Pin

Symbol

Function

1

COIL1

Coil input 1, Pin to connect an LC antenna for communication and field supply

2

COIL2

Coil input 2, Pin to connect an LC antenna for communication and field supply

3

VBATT

Power-supply voltage input to connect a battery

4VDD

Power-supply voltage for the microcontroller and EEPROM. At this pin a capacitor (0.5 µF to 10 µF)

must be connected to buffer the voltage during field supply and to block the V

microcontroller.

5

BP40/SC/INT3

I/O-port line/serial clock line/INT3 input (falling edge sensitive)

6

BP53/INT3

I/O-port line/INT3 interrupt input (falling or rising edge sensitive)

7

BP50/INT6

I/O-port line/INT6 interrupt input (falling or rising edge sensitive)

8

OSC1/ROSC

Oscillator- or external system-clock input/input for RC-oscillator resistor

9

OSC2

Oscillator output

10

BP60/T3O

Bi-directional I/O-line/Timer 3 output/modulator output

11

BP63/T3I/INT5

I/O-port line/INT5 interrupt input/Timer 3 input/demodulator input

12

BP20/NTE

BP20-I/O-port line/test mode input. This input is used to control the test modes. During POR it must

13

BP23

I/O-port line

14

BP41/VMI

I/O-port line/Voltage monitor input/Timer 2 input

15

BP42/T2O

I/O-port line/Timer 2 output/modulator output

16

BP43/SD/INT3

I/O-port line/serial data line/INT3 input (falling edge sensitive)

17

VSS

Circuit ground

18

FC

Field clock output of the clock extractor

19

MOD

Modulation input - front end. Must be connected to the modulator output T2O.

20

NGAP

Gap detect output - front end. Must be connected to the demodulator input T3I.