HT7466 Ver la hoja de datos (PDF) - Holtek Semiconductor

Número de pieza

componentes Descripción

Fabricante

HT7466

3A Step-Down DC to DC Converter

Holtek Semiconductor 

HT7466

Output Capacitor

The output capacitor is required to maintain the DC

output voltage. Ceramic or low ESR electrolytic

capacitors is the rule to choice of external load

capacitor is also critical and low ESR value capacitors

must be used to ensure stability. This capacitor must

be connected very close to the inductor, with short

traces for good noise performance.

Schottky Diode

The output diode conducts when the internal power

MOSFET is switched off. There are three important

electrical parameters to consider when choosing the

diode:

• The diode maximum reverse voltage value must be

greater than the maximum input voltage.

• Short recovery time and low forward voltage -- use

a schottky diode type.

• Diode current rating should be greater than the

maximum load current.

Layout Considerations

Circuit board layout is a very important consideration

for switching regulators if they are to function

properly. Poor circuit layout may result in related

noise problems. In order to minimise EMI and

switching noise, follow the guidelines below:

• All tracks should be as wide as possible.

• The input and output capacitors, C1 (C8) and C6

(C7), should be placed close to the VIN, VOUT

and GND pins (C1 and C8 is parallel; C6 and C7 is

parallel).

• The Schottky diode D and inductor L must be

placed close to the SW pin.

• Feedback resistor, R1 (R1-1) and R2, must be

placed close to the FB and GND pins (R1 and R1-1

is series).

• A full ground plane is always helpful for better

EMI performance.

A recommended PCB layout with component

locations is shown below.

Top Layer

Bottom Layer

Rev. 1.00

5

September 02, 2011

Share Link: