TK5561A-PP Atmel, TK5561A-PP Datasheet - Page 8

• Manufacturer Part Number: TK5561A-PP
• Description: IC TRANSPONDR CRYPTO SHORT CYCLE
• Manufacturer: Atmel
• Series: TK5561r

Specifications of TK5561A-PP

• Rf Type: Read / Write
• Frequency: 125kHz
• Features: 320-bit EEPROM
• Package / Case: Plastic Package - 12mm L x 6mm W x 3mm H
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

10. Actual Device Behavior
Figure 10-1. Ideal and Actual Signal Behavior
11. Operating Distance
8
TK5561A-PP
Gap detect
Coil
voltage
Ideal behavior
RF level reduces to zero immediately
The TK5561A-PP detects a gap if the voltage across the coils decreases below a peak-to-peak
value of about 800 mV. Until then, the clock pulses are counted. The number given for a valid 0
or 1 (see
ever, there are always more clock pulses being counted than were applied by the base station.
The reason for this is the fact that an RF field cannot be switched off immediately. The coil volt-
age decreases exponentially. So although the RF field coming from the base station is switched
off, it takes some time until the voltage across the coils reaches the threshold peak-to-peak
value of about 800 mV and the device detects the gap. Referring to the following diagram
10-1, this means that the device uses the times t
and t
Typical time frames are:
Antennas with a high Q-factor require longer times for t
The maximum distance between the base station and the TK5561A-PP depends mainly on the
base station, the coil geometries and the chosen modulation options. Typical distances are 0 to
3 cm. A general maximum distance value cannot be given. A convenient way is to measure the
TK5561A-PP within its environment. Rules for a correct base-station design can be provided
upon request (see Antenna Design Guide).
1
t
1
1
t
t
t
t
are dependent on the application (e.g., field strength, etc.)
gap
0
1
gap
Figure 9-1 on page
= 150 to 400 µs
= 60 to 140 µs
= 300 to 400 µs
t
0
0
1
7) refers to the actual clock pulses counted by the device. How-
Gap detect
Coil
voltage
0
RF level decreases exponentially
Actual behavior
internal and t
t
1 internal
t
1
1
gap
t
and shorter time values for t
gap
t
t
0
0
0 internal
1
internal. The exact times for t
1
4682D–RFID–09/06
0
and t
Figure
1
.
0