35-75 V
5.0 V
Input:
Output:
Current:
Package:
30 A
Quarter-brick
Technical Specification
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 electrolytic input
capacitor. The recommended external input capacitance is speci-
fied in the “Input Characterisitcs” section. More detailed informa-
tion is available in the application note titled “EMI Characteristics”
on the SynQor website.
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 correcting it.
Application Circuits: Figure D below provides a typical circuit
diagram which details the input filtering and voltage trimming.
Vout(+)
Vin(+)
Electrolytic
Capacitor
Vsense(+)
External
Input
Filter
Rtrim-up
Vin
Trim
or
ON/OFF
Cload
Rtrim-down
Iload
V
sense(_)
out(_)
V
in(_)
V
Figure D: Typical application circuit (negative logic unit, permanently enabled).
Vin(+)
C2
C1
Vin(_)
Figure E: Internal Input Filter Diagram (component values
listed on page 3).
Product # PQ60050QTA30
Phone 1-888-567-9596
www.synqor.com
Doc.# 005-2QT650C Rev. E
05/20/09
Page 11
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