LRIS2K_08 Datasheet, PDF (19/102 Pages) STMicroelectronics – 2048-bit EEPROM tag IC at 13.56 MHz, with 64-bit UID and Password, ISO15693 and ISO18000-3 Mode 1 compliant

LRIS2K
Communication signal from VCD to LRIS2K
4
Communication signal from VCD to LRIS2K
Communications between the VCD and the LRIS2K takes place using the modulation
principle of ASK (Amplitude Shift Keying). Two modulation indexes are used, 10% and
100%. The LRIS2K decodes both. The VCD determines which index is used.
The modulation index is defined as [a – b]/[a + b] where a is the peak signal amplitude and
b, the minimum signal amplitude of the carrier frequency.
Depending on the choice made by the VCD, a "pause" will be created as described in
Figure 3 and Figure 4.
The LRIS2K is operational for any degree of modulation index from between 10% and 30%.
Figure 3.
100% modulation waveform
a
105%
100%
95%
60%
5%
tRFF
tRFR
tRFSBL
Table 10. 10% modulation parameters
Symbol
Parameter definition
hr
0.1 x (a – b)
hf
0.1 x (a – b)
t
AI06683
Value
max
max
19/102