
210 Analog Circuits Cookbook
this reason, the recommended switching and steady state gate voltages are
as shown in Figure 7.12.
To meet these requirements, the circuit of Figure 7.13(a) was sketched
out, using a 2N5859 (n-p-n) and 2N4406s (p-n-ps). Both types are switching
transistors, rated at 2 A and 1.5 A continuous collector current respectively,
so they seemed at first sight a plausible choice since to charge a C{
ss
Figure
7.12 Recommended boundary limits for MCT gate waveform
(b)
b
3705
0R1
|
(c)
Figure
7.13 (a) Useless gate driver circuit Mark 1. (b) Gate driver circuit using the
Unitrode UC3705N. (c) Internal circuit
(a)