ATA559001-DBW Atmel, ATA559001-DBW Datasheet - Page 97

• Manufacturer Part Number: ATA559001-DBW
• Description: RF Wireless Misc UHF (1kbit r/w anti- collis. Ni-Au)
• Manufacturer: Atmel

Specifications of ATA559001-DBW

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

14.1.2
14.2
4817C–RFID–03/07
Notch Detection
Ramp Down
If RF field strength is decreasing, VDD goes down to the threshold voltage level of stand_by.
Current consumption decreases because the oscillator is stopped. Therefore, the gradient of the
VDD curve decreases also. If VDD passes the threshold voltage of POR, the circuit will be reset.
The gradient of VDD decreases again because the band gap circuit is switched off.
Figure 14-2. Power Down Timing
The notch detection is based on an RSSI concept. Therefore, the tag cannot detect the differ-
ence between PR-ASK, ASK, or AM. Nevertheless, the type of modulation has an influence on
the power transport, the SNR, and the spectrum (necessary bandwidth).
Figure 14-3
Figure 14-3. Relationship Between Notch Detection and Modulation Using PR-ASK Modula-
Stand_by
VDD
POR
shows the relations between modulation and notch detection.
tion Scheme
U
Notch
mod
+ 1
- 1
0
U
T
notch_on
notch1
U
notch_off
ATA5590
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