HT7465 Datasheet, PDF (6/11 Pages) Holtek Semiconductor Inc – 2A Step-Down DC to DC Converter

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.
HT7465
SOP8 Bottom Layer
MSOP10 Top Layer
Rev. 1.00
SOP8 Top Layer
MSOP10 Bottom Layer
6
September 02, 2011