M24LR64-R_12 Datasheet, PDF (40/128 Pages) STMicroelectronics – 64 Kbit EEPROM with password protection & dual interface: 400 kHz I²C serial bus & ISO 15693 RF protocol at 13.56 MHz

Communication signal from VCD to M24LR64-R
M24LR64-R
8
Communication signal from VCD to M24LR64-R
Communications between the VCD and the M24LR64-R takes place using the modulation
principle of ASK (Amplitude Shift Keying). Two modulation indexes are used, 10% and
100%. The M24LR64-R 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 14 and Figure 15.
The M24LR64-R is operational for any degree of modulation index from between 10% and
30%.
Figure 14. 100% modulation waveform
Carrier
Amplitude
t₁
t₃
t₄
105%
a
95%
60%
t₂
5%
b
t
Min (µs) Max (µs)
t1
6,0
9,44
t2
2,1
t1
t3
0
4,5
t4
0
0,8
The clock recovery shall be operational after t₄ max.
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Doc ID 15170 Rev 14