4

Application information

Figure 27. Application schematic

Vs

EN

Ishort

RST

SEL1

T2

GND

Rsh

Vo

TW

Vbat

C 1

C 2

Co

RRST

T1

SEL3

SEL2

Figure 28. Application schematic – Post regulation

GND

Rsh

Vo

V in

C 1

C 2

Co

DC/DC

CONVERTER

OR

PRE-REGULATOR

Vbat

Vs

EN

Ishort

T1

T2

TW

R ST

SEL1

RRST

SEL2

SEL3

Input ceramic capacitor C2 ≥ 4.7 μF is necessary for the regulator to operate properly. The other input capacitor

C1 can be used as backup supply for the application. The C0 capacitor, connected to the output pin, is for

bypassing to GND the high-frequency noise and it guarantees stability even during sudden line and load

variations.

Suggested value is C0 = 3.3 µF.

The ESR of the SMD output ceramic capacitor has a negligible effect on the stability of the L99VR01 family for

capacitors with low ESR. A ceramic SMD capacitor is recommended on Vo pin.

L99VR01

Application information

DS13649 - Rev 4

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