Technical Reference Notes

ALD12/18/20/25 Series

(Single Output 16

MODEL: ALD12/18/20/25 SERIES

SHEET 5 OF 20

AUGUST 17, 2005 – REVISION C

Electrical Specifications (continued)

SAFETY AGENCY / MATERIAL RATING / ISOLATION

Parameter

Device

Safety Approval

All

UL/cUL 60950

TUV EN 60950

Material Flammability Rating

All

UL94V-0

Parameter

Device

Symbol

Min

Typical

Max

Unit

Input to Output Capacitance

All

-

1000

-

pF

Input to output Resistance

All

-

10

-

Mohms

Input to Output Insulation Type

All

-

Basic

-

-

Figure 2. Peak to Peak Output Noise Measurement Setup.

Figure 1. Input Reflected Ripple Current Measurement Setup.

Vo(+)

Vo(-)

RESISTIVE

LOAD

10 uF

0.1 uF

SCOPE

COPPER STRIP

Use a 0.1

µF @50V X7R ceramic capacitor (connected an inch away from the output

terminals of the UUT) and a 10

µF @ 25V tantalum capacitor (2 inches away from the output

terminals of the UUT). Scope measurement should be made using a BNC socket, positioned 3

inches away from output terminals of the converter.

BATTERY

Cs 220 uF

ESR < 0.1 OHM

@ 20 ºC, 100 kHz

Ltest

12 uH

33 uF

ESR < 0.7 OHM

@ 20 ºC, 100 kHz

Vi(+)

Vi(-)

TO OSCILLOSCOPE

Measure input reflected-ripple current with a simulated source inductance (Ltest) of 12 uH.

Capacitor Cs offsets possible battery impedance. Measure current as shown above.