Datasheet

MC34063A, MC33063A, NCV33063A
http://onsemi.com
6
9a. External NPN Switch 9b. External NPN Saturated Switch
(See Note 8)
8
7
6
R
sc
V
in
1
2
V
out
R
R ³ 0 for
constant V
in
8. If the output switch is driven into hard saturation (non−Darlington configuration) at low switch currents (≤ 300 mA) and high driver current
s
(≥ 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.
8
7
6
R
sc
V
in
1
2
V
out
Figure 9. External Current Boost Connections for I
C
Peak Greater than 1.5 A