HT7465 datasheet(6/11 Pages) HOLTEK

6 / 11 page

Rev. 1.00

September 02, 2011

HT7465

mustbeusedtoensurestability.Thiscapacitormust

beconnectedveryclosetotheinductor,withshort

tracesforgoodnoiseperformance.

Schottky Diode

Theoutputdiodeconductswhentheinternalpower

MOSFETisswitchedoff.Therearethreeimportant

electricalparameterstoconsiderwhenchoosingthe

diode:

• Thediodemaximumreversevoltagevaluemustbe

greaterthanthemaximuminputvoltage.

• Shortrecoverytimeandlowforwardvoltage--use

aschottkydiodetype.

• Diodecurrentratingshouldbegreaterthanthe

maximumloadcurrent.

Layout Considerations

Circuitboardlayoutisaveryimportantconsideration

for switching regulators if they are to function

properly.Poorcircuitlayoutmayresultinrelated

noise problems. In order to minimise EMI and

switchingnoise,followtheguidelinesbelow:

• Alltracksshouldbeaswideaspossible.

• Theinputandoutputcapacitors,C1(C8)andC6

(C7),shouldbeplacedclosetotheVIN,VOUT

andGNDpins(C1andC8isparallel;C6andC7is

parallel).

• TheSchottkydiodeDandinductorLmustbe

placedclosetotheSWpin.

• Feedbackresistor,R1(R1-1)andR2,mustbe

placedclosetotheFBandGNDpins(R1andR1-1

isseries).

• Afullgroundplaneisalwayshelpfulforbetter

EMIperformance.

ArecommendedPCBlayoutwithcomponent

locationsisshownbelow.

SOP8 Top Layer

SOP8 Bottom Layer

MSOP10 Top Layer

MSOP10 Bottom Layer

HT7465 Fiches technique(PDF) 6 Page - Holtek Semiconductor Inc