Product # PQ60010QTA40

Phone 1-888-567-9596

www.synqor.com

Doc.# 005-2QT601C Rev. B

10/1/04

Page 11

T

pecification

Input:

Input:

Output:

Output:

Current:

Current:

P

ackage:

35-75 V

35-75 V

1.0 V

1.0 V

40 A

40 A

Quarter-brick

Quarter-brick

value.

APPLICATION CONSIDERATIONS

Input System Instability: This condition can occur because

any DC/DC converter appears incrementally as a negative

resistance load. A detailed application note titled “Input

System Instability” is available on the SynQor web site

(www.synqor.com) which provides an understanding of why

this instability arises, and shows the preferred solution for cor-

recting it.

Application Circuits: Figure D below provides a typical cir-

cuit diagram which details the input filtering and voltage trim-

ming.

Input Filtering and External Capacitance: Figure E below

provides a diagram showing the internal input filter components.

This filter dramatically reduces input terminal ripple current,

which otherwise could exceed the rating of an external elec-

trolytic input capacitor. The recommended external input capac-

itance is specified in the “Input Characterisitcs” section. More

detailed information is available in the application note titled

“EMI Characteristics” on the SynQor website.

External

Input

Filter

Trim

L

or

ON/OFF

Electrolytic

Capacitor

47µF

Figure D: Typical application circuit (negative logic unit, permanently enabled).

C