L4921 datasheet(4/7 Pages) STMICROELECTRONICS

Numer części	L4921

Szczegółowy opis	VERY LOWDROP ADJUSTABLE REGULATORS

PDF	7 Pages

Scroll/Zoom	100%

Producent	STMICROELECTRONICS [STMicroelectronics]

Strona internetowa	http://www.st.com

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4 / 7 page

Figure 3 : Quiescent Current vs. Output Current

(Vo = 5V).

APPLICATION INFORMATION

1) The L4920 and L4921 have VREF

≅ 1.25V.Then

the output voltage can be set down to VREF but

Vi must be greater than 5.2V (Tj =25

°C).

2) As the regulator reference voltage source works

in closed loop, the reference voltage may change

in foldbackcondition.

3) For applications with high Vl, the total power

dissipation of the device with respect to the ther-

mal resistance of the package may be limiting . The

total power dissipation is :

Ptot =Vi lq +(Vi -Vo)lo

A typical curve giving the quiescent current lq as a

function of the output current lo is shown in fig. 3.

Figure 1 : Output Voltage vs. Temperature.

Figure 2 : Foldback Current Limiting.

L4920/L4921

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L4921 Arkusz danych(PDF) 4 Page - STMicroelectronics