
MCD10089 Rev. 1.1, 8-Oct-08
Page 2 of 9
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QKS48T21120 DC-DC Bus Converter Data Sheet
Quarter-Brick with 48VDC Input; 12VDC @ 21A Output
Absolute Maximum Ratings
Stresses in excess of the absolute maximum ratings may cause performance degradation, adversely effect long-
term reliability, and cause permanent damage to the converter.
Parameter
Conditions/Description
Input Voltage
Continuous
Transient, 100 ms
Operating Temperature
PC Board Temperature
Storage Temperature
Min
Max
75
100
100
125
Units
VDC
VDC
°
C
°
C
-40
-40
Environmental and Mechanical Specifications
All specifications apply over specified input voltage, output load, and temperature range, unless otherwise noted.
Parameter
Conditions/Description
Operating Humidity
Relative Humidity, Non-cond.
Storage Humidity
Relative Humidity, Non-cond.
Shock
(Half-sinewave, 6ms), 3 axes
Sinusoidal Vibration
GR-63-CORE, Section 5.4.2
Weight
Water Washing
Standard process
MTBF
Per Bellcore TR-NWT-000332
Min
Nom
50
1
1.2/35
Yes
1.8
Max
95
95
Units
%
%
g
g
Oz/g
MHrs
Isolation Specifications
All specifications apply over specified input voltage, output load, and temperature range, unless otherwise noted.
Parameter
Conditions/Description
Insulation Safety Rating
Isolation Voltage
Input to Output
Isolation Resistance
Isolation Capacitance
Min
Nom
Basic
1000
Max
Units
VDC
MOhm
pF
1500
10
Input Specifications
All specifications apply over specified input voltage, output load, and temperature range, unless otherwise noted.
Parameter
Conditions/Description
Input Voltage
Continuous
Input Undervoltage Lockout
Turn-on Voltage Threshold
Turn-off Voltage Threshold
Hysteresis
Power up Turn-on delay time
(Time from V
IN
@ UVLO to Vo @
10% of Vo nominal)
Enable Turn-on delay time
(Time from V
enable
@ 0.8V to Vo
@ 10% of Vo nominal)
Min
36
33.5
32
1.5
Nom
48
34.5
33
Max
75
35.5
34
Units
VDC
Vin
V
All
0.5
30
ms
All
0.5
11
ms