MC34063A, MC33063A, SC34063A, SC33063A, NCV33063A
8
1
V
out
R
8
1
V
out
7
2
R
sc
7
2
R
sc
V
in
6
V
in
6
R
³
0 for
constant V
in
Figure 10. External Current Boost Connections for I
C
Peak Greater than 1.5 A
9a. External NPN Switch
9b. External NPN Saturated Switch
(See Note 8)
8. If the output switch is driven into hard saturation (non−Darlington configuration) at low switch currents (≤ 300 mA) and high driver currents
(≥ 30 mA), it may take up to 2.0
ms
to come out of saturation. This condition will shorten the off time at frequencies
≥
30 kHz, and is magnified
at high temperatures. This condition does not occur with a Darlington configuration, since the output switch cannot saturate. If a
non−Darlington configuration is used, the following output drive condition is recommended.
http://onsemi.com
6