TDA5225 Datasheet, PDF (73/176 Pages) Infineon Technologies AG – Enhanced Sensitivity Multi-Channel Quad-Configuration Receiver

TDA5225
Functional Description
Depending on the bit content, the same type of edge (e.g. rising edge) is sometimes
shifted and sometimes not.
With this definition the Manchester duty cycle is calculated to
MDC_A = _T--T--b--^H-_i-_t = ^T----c---^h--Tⁱ--^p--_b--+-_i--_t--^Δ----T--
Chip-based Definition
MDC = Duration of the first chip / Symbol period
bit = 1
1
0
0
1
1. chip
2. chip
T_{c hip}
T
b it
MDC < 50%
1
1
0
0
1
ΔT
T_{c hip}
T_{1 .ch ip}
T_{b it}
MDC > 50%
T_{1.ch ip}
T_{b it}
ΔT
T_{c hip}
T
1.ch ip
T_{b it}
T
1 .chip
T_{b it}
Figure 49 Definition B: Chip-based definition
This definition determinates the duty cycle to be the ratio of the first symbol chip and the
ideal symbol period independently of the information bit content. The DC content
depends on the information bit and it is balanced only if the message itself is balanced.
For ΔT > 0 the first chip-period is longer than the ideal chip-period and for ΔT < 0 the first
chip-period is shorter than the ideal chip-period.
Depending on the bit content, the same type of edge (e.g. rising edge) is sometimes
shifted and sometimes not.
Data Sheet
73
V1.0, 2010-02-19