MC34063A, MC33063A, NCV33063A

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6

9a. External NPN Switch

9b. External NPN Saturated Switch

(See Note 8)

8

7

6

1

2

R

R

³ 0 for

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.

8

7

6

1

2