CD00257532 Datasheet, PDF (12/19 Pages) STMicroelectronics – Application information

Application information
Figure 5. Output voltage vs input voltage
L4949ED-E, L4949EP-E
Figure 6. Quiescent current vs supply voltage
3.4
Preregulator
To improve the transient immunity a preregulator stabilizes the internal supply voltage to 5 V.
This internal voltage is present at Pin 3 (V_Z). This voltage should not be used as an output
because the output capability is very small (≤ 10 µA).
This output may be used as an option when a better transient behaviour for supply voltages
less than 8 V is required (see also application note).
In this case a capacitor (100 nF - 1 µF) must be connected between pin V_Z and GND. If this
feature is not used pin V_Z must be left open.
12/19
Doc ID 16823 Rev 1