AND8019/D

http://onsemi.com

2

Manufacturers Contact Data

Mfr.

Phone

Web

ON Semiconductor

800 282–9855

www.onsemi.com

Cooper Electronics

561 752–5000

www.cooperet.com

TDK

847 803–6100

www.component.tdk.com

Mallory

317 273–0090

www.nacc–doesit.com

Vishay/...

818 781–1642

www.vishay.com/index.html

Lumex

847 359–2790

www.lumex.com

Beau Interconnect

603 524–5101

www.beauint.com

Panasonic

–

www.panasonic.com

Board Evaluation

The following Power Supply Test Setup diagram and

description is designed to allow the board to be tested for all

parameters listed in the Converter Test Data table. This may

be used to confirm proper operation of the board, as well as

operating parameters of modified boards.

Volt

or

Watt

Meter

85 vac–265 vac

50 Hz–60 Hz

Scope

UUT

Load Fixture

500 mA

90 mA

1A

V

55

W

12

W

10

W

Figure 1. Power Supply Test Setup

Test Setup

The input power source needs to be variable over the range

of voltages and frequencies that you choose to test. This can

be either a variac or an electronic power source.

Connect it to a voltmeter or wattmeter. A wattmeter will be

required to measure efficiency. If none is available, use a

voltmeter. The output of the meter will be fed into the input

connector on the board. The polarity is not important as this

converter has an isolated output. Please keep in mind that the

input side of this circuit is hot – including the ground.

The output connector should be connected to an ammeter

in the high line, and then to a set of load resistors. The 12

W

and 10

W resistors should be rated at 10 watts, and the 55 W

at 2.0 watts.

Any lab scope with at least a 20 MHz bandwidth will be

adequate to observe ripple and switching waveforms.

The unit will not be damaged by input voltages below

85 volts, but may not operate properly. Do not exceed the

265 volt rating as this could damage the NCP1000 as well as

other components.

Measurement Techniques

To accurately measure the output voltage and ripple, the

voltmeter and oscilloscope probes should be connected as

close as possible to the output terminals of the board.

Measuring the output voltage at the load resistors will result

in errors due to the impedance of the ammeter and of the lead

wires.

Ripple measurements often contain large amounts of

common mode noise. Before taking measurements, connect

the scope probe to the ground lead at the negative output

terminal. Any spikes that are on the screen of the scope are

common mode noise that is being picked up by the scope

leads, and are not part of the output ripple. This phenomenon

may be reduced by using two scope probes in a differential

measurement mode.

Connect both ground leads to the negative output

terminal. Connect one scope probe to the negative terminal

also, and the other to the positive terminal. Set the scope up

to subtract the ground signal from the ripple signal, and the

resulting waveform will be a more accurate representation

of the ripple.