Product # PQ60015EGL25

Phone 1-888-567-9596

www.synqor.com

Doc.# 005-2EG651D Rev. B

1/22/08

Page 11

Input:

Input:

Output:

Output:

Current:

Current:

ackage:

35-75 V

35-75 V

1.5 V

1.5 V

25 A

25 A

Eighth-brick

Eighth-brick

T

pecification

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 website which

provides an understanding of why this instability arises, and

shows the preferred solution for correcting it.

Application Circuits: Figure D provides a typical circuit dia-

gram which details the input filtering and voltage trimming.

Input Filtering and External Capacitance: Figure E pro-

vides 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 Characteristics” section. More

detailed information is available in the application note titled

“EMI Characteristics” on the SynQor website.

External

Input

Filter

Trim

L

C

or

ON/OFF

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

Electrolytic

Capacitor

47µF