m24lr64-r STMicroelectronics, m24lr64-r Datasheet - Page 39

• Manufacturer Part Number: m24lr64-r
• Description: 64 Kbit Eeprom With Password Protection & Dual Interface 400 Khz I?c Serial Bus & Iso 15693 Rf Protocol At 13.56 Mhz
• Manufacturer: STMicroelectronics

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
The M24LR64-R is operational for any degree of modulation index from between 10% and
30%.
Figure 14. 100% modulation waveform
The clock recovery shall be operational after t
105%
95%
60%
and
5%
Amplitude
a
b
Carrier
Figure
15.
Doc ID 15170 Rev 9
t
1
t
2
t
4
4
t
Communication signal from VCD to M24LR64-R
max.
3
t
t
t
t
t
1
2
3
4
Min (µs)
ai15793
6,0
2,1
0
0
Max (µs)
9,44
4,5
0,8
t
1
39/126