Technical Reference Notes
ALD12/18/20/25 Series
(Single Output 16th Brick)
Electrical Specifications (continued)
SAFETY AGENCY / MATERIAL RATING / ISOLATION
Parameter
Device
Safety Approval
All
UL/cUL 60950
TUV EN 60950
UL94V-0
Material Flammability Rating
Parameter
Input to Output Capacitance
All
Device
All
Symbol
Min
Typical
Max
Unit
-
-
-
1000
-
pF
Input to output Resistance
All
All
10
-
-
Mohms
-
Input to Output Insulation Type
Basic
TO OSCILLOSCOPE
Vi(+)
Ltest
12 uH
Cs 220 uF
ESR < 0.1 OHM
@ 20 ºC, 100 kHz
33 uF
ESR < 0.7 OHM
@ 20 ºC, 100 kHz
BATTERY
Vi(-)
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.
Figure 1. Input Reflected Ripple Current Measurement Setup.
COPPER STRIP
Vo(+)
RESISTIVE
LOAD
0.1 uF
10 uF
SCOPE
Vo(-)
Use a 0.1µF @50V X7R ceramic capacitor (connected an inch away from the output
terminals of the UUT) and a 10µF @ 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.
Figure 2. Peak to Peak Output Noise Measurement Setup.
MODEL: ALD12/18/20/25 SERIES
AUGUST 17, 2005 – REVISION C
SHEET 5 OF 20
ASTEC [ Astec America, Inc ]
