NGA SERIES

Non-Isolated Wide Input DC/DC Converters

APPLICATION NOTES

EXTERNAL CAPACITANCE

External capacitors are necessary in

order to guarantee stability and full

parametric performance over the full line

and load range. All parts have

been tested and characterised using the

following values and test circuit.

TEST CIRCUIT

C

IN

C

OUT

100µF, 50V

100µF, 10V

++

GND

GND

NGA

C&D Technologies (NCL) Ltd

Tanners Drive, Blakelands North

Milton Keynes MK14 5BU, England

Tel: +44 (0)1908 615232

Fax: +44 (0)1908 617545

email: info@cdtechno-ncl.com

www.cdpoweronline.com

C&D Technologies Inc.

3400 E Britannia Drive, Tucson,

Arizona 85706, USA

Tel: +1 (800) 547-2537

Fax: +1 (520) 741-4598

email: sales@cdtechno.com

C&D Technologies (NCL) Limited reserve the right to alter or improve the

specification, internal design or manufacturing process at any time, without

notice. Please check with your supplier or visit our web site to ensure that

you have the current and complete specification for your product before use.

© C&D Technologies (NCL) Limited 2003

NDC NGA.3

No part of this publication may be copied, transmitted or stored in a

retrieval system or reproduced in any way including, but not limited to,

photography, photocopy, magnetic or other recording means, without prior

written permission from C&D Technologies (NCL) Limited.

Instructions for use are available from www.cdpoweronline.com

2 Accuracy of adjustment is subject to tolerance of resistors and initial output accuracy.

SHUTDOWN

When the shutdown pin is shorted to the

0V, the device’s output will be disabled.

To shutdown the device the pin should be

taken below 0.8V using either an open

collector pull down or by using isolated

relay contacts. To enable the device

output the shutdown pin should be left

floating or taken no less than +1.5V to

MAX (+28V).

If the shutdown pin is to be connected to

a long wire, it is recommended that a

capacitor (10nF) decouples the shutdown

pin to the 0V in order to avoid the risk of

injecting noise into the device circuit.

VOLTAGE TRIMMING

The trimming (adjust) input on the device

allows output voltage adjustment to within

with a value determined by the following

equations.

When open circuit, the output will be +5V.

the output pin will adjust the output

voltage between +5V to +1.8V.

1 = (22(1.028V

–1

–0.011

the 0V pin will adjust the device output

from +5V to +5.5V.

91

0.0455

NGA

NGA

OFF

ON

BC182 or equiv

10nF

(optional)

TTL

1KΩ

SD

0V

NGA

SD

0V