T555401N-DDW Atmel, T555401N-DDW Datasheet - Page 4

• Manufacturer Part Number: T555401N-DDW
• Manufacturer: Atmel

Specifications of T555401N-DDW

• Screening Level: Industrial
• Lead Free Status / Rohs Status: Supplier Unconfirmed

3.10
4
Modulator
T5554
The modulator consists of several data encoders in two stages, which may be freely combined
to obtain the desired modulation. The basic types of modulation are:
Note:
Figure 3-2.
• PSK: phase shift: 1) every change; 2) every “1”; 3) every rising edge (carrier: fc/2, fc/4 or fc/8)
• FSK: 1) f1 = rf/8 f2 = rf/5; 2) f1 = rf/8, f2 = rf/10
• Manchester: rising edge = H; falling edge = L
• Biphase: every bit creates a change, a data “H” creates an additional mid-bit change
– Stage1 Manchester or Biphase and stage2 PSK, at any PSK carrier frequency
– Stage1 Manchester or Biphase and stage2 PSK with bitrate = rf/8 and PSK carrier
–
(because the first stage output frequency is higher than the second stage strobe
frequency);
frequency = rf/8 (for the same reason as above);
Any stage1 option with any PSK for bitrates rf/50 or rf/100 if the PSK carrier frequency is not
an integer multiple of the bitrate (e.g., br = rf/50, PSKcf = rf/4, because 50/4 = 12.5). This
because the PSK carrier frequency must maintain constant phase with respect to the bit clock.
The following modulation type combinations will not work:
From memory
Modulator Block Diagram
Manchester
Biphase
Direct
Carrier frequency
Mux
FSK1, 1a
FSK2, 2a
PSK1
PSK2
PSK3
Direct
Mux
To load
4576D–RFID–12/06
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