8
7
VIN
6
5
RT34063A
1
VOUT
2
3
4
(a) External NPN Switch
8
7
VIN
6
5
R
1
2
3
4
VOUT
R 0 for
Constant VIN
(b) External NPN Saturated Switch (See Note)
Figure 2. External Current Boost Connections for IC Peak Greater than 1.5A
Note: If the output switch is driven into hard saturation (non-Darlington configuration) at low switch current≤s ( 300mA) and
high driver curren≥ts ( 30mA), it may take up to 2.0μs to come out of saturation. This condition will shorten the off time at
frequencies ≥ 30kHz, and is magnified at high temperature. 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.
DS34063A-13 March 2007
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