YEV09T03 3A DC-DC POL Converter

Data Sheet

ZD-01968 Rev 1.1, 25-Mar-09

www.power-one.com

Page 7 of 10

Figure 10.

Transient Response to Dynamic Load Change

from 40% to 80% of full load (Vin=12V,

Vo=2.5Vdc). Ch3 – Iout. Scale=0.2A/mVΩ

Figure 11.

Transient Response to Dynamic Load Change

from 40% to 80% of full load (Vin=12V,

Vo=3.3Vdc). Ch3 – Iout. Scale=0.2A/mVΩ

6.

Application Information

6.1

Input and Output Impedance

The POL converter should be connected to the DC

power source via low impedance.

In many

applications, the inductance associated with the

distribution from the power source to the input of the

converter can affect the stability of the converter.

Internally, the converter includes 4.7μF (low ESR

ceramics) of input capacitance which eliminates the

need for external input capacitance. However, if the

distribution of the input voltage to the POL converter

contains high inductance, it is recommended to add

a 100μF decoupling capacitor placed as close as

possible to the converter input pins.

A low-ESR

tantalum or POS capacitor connected across the

input pins help ensuring stability of the POL

converter and reduce input ripple voltage.

A 22μF ceramic output capacitor is recommended to

improve output ripple and dynamic response.

It is important to keep low resistance and low

inductance of PCB traces for connecting load to the

output pins of the converter in order to maintain good

load regulation.

6.2

Output Voltage Programming

The output voltage can be programmed from 0.59V

between TRIM pin (Pin 5) and GND pin (Pin 3), as

shown in Figure 12.

Figure 12. Programming Output Voltage With A Resistor

can be calculated using the following equation:

,

591

.

0

182

.

1





OUT

TRIM

V

R

kΩ

VIN

GND

ON/OFF

VOUT

3

2

4

1

TRIM

5

Rload

YEV09T03