Renesas Hitachi H8S/2194 Series Hardware Manual page 764

(2) Frequency Characteristics
The computation circuit repeats computation of the function, which is obtained by s-z
conversion according to bi-linear approximation of the transfer function on the s-plane.
Figure 28.41 shows the frequency characteristics of the lag-lead filter.
0
Figure 28.41 Frequency Characteristics of the Lag-Lead Filter
The pulse transfer function G(Z) is obtained by the bi-linear approximation of the transfer
function G (S).
In the transfer G (S),
-1
2 1−Z
⋅
S=
-1
Ts 1+Z
Where, assumed that Z
2 1+AZ
G (Z) = G ⋅ ⋅
Ts 1+BZ
1
Ts+
πf
2
G (Z) =
1
Ts+
πf
Ts: Sampling cycle (sec)
20log(f1/f2)
-jωTs
-1
= e ,
-1
-1
1
Ts −
πf
2
A =
1
Ts+
πf
1 2
f1 f2
1
Ts −
πf
1
B =
1
Ts+
πf
1
Rev. 2.0, 11/00, page 737 of 1037
Frequency (Hz)