HEIDENHAIN PWM 20 - Manual (Page 212)

November 2014 Interface description 213
Signal diagram: Incremental signals 1 Vpp
Recommended input circuit of the subsequent electronics 1 Vpp
Dimensioning Operational amplifier e.g. MC 34074; RC 4157
R
1
= 10 k
 and C
1
= 100 pF
R
2
= 34.8 k
 and C
2
= 10 pF
Z
0
= 120

U
B
=
 15 V
U
1
approx. U
0
3 dB cutoff frequency of the circuit
Approx. 450 kHz
Approx. 50 kHz with C
1
= 1000 pF and C
2
= 82 pF
(Recommended for electronics that are sensitive to electro-magnetic interference)
Circuit output signals
U
a
= 3.48 Vpp typ.
3.48-fold amplification
Note
This variant does reduce the bandwidth of the circuit, but in doing so it improves its noise
immunity.