L4921 datasheet(4/7 Pages) STMICROELECTRONICS

部件名	L4921

功能描述	VERY LOWDROP ADJUSTABLE REGULATORS

PDF	7 Pages

Scroll/Zoom	100%

制造商	STMICROELECTRONICS [STMicroelectronics]

网页	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

4/7

L4921 数据表(PDF) 4 Page - STMicroelectronics