VHB75W-Q24-S12 CUI Inc, VHB75W-Q24-S12 Datasheet - Page 4
![CONVERTER DC/DC 75W 12V 6.25A](/photos/40/8/400870/mfg_vhb75w-dual_series_sml.jpg)
VHB75W-Q24-S12
Manufacturer Part Number
VHB75W-Q24-S12
Description
CONVERTER DC/DC 75W 12V 6.25A
Manufacturer
CUI Inc
Series
V-Infinity VHB75Wr
Type
With Remote On/Off and UVLOr
Datasheet
1.VHB75W-Q24-S12.pdf
(10 pages)
Specifications of VHB75W-Q24-S12
Voltage - Input (min)
9V
Voltage - Input (max)
36V
Number Of Outputs
1
Power (watts) - Manufacture Series
75W
Power (watts) - Max
75W
1st Output
12 VDC @ 6.25A
2nd Output
-
3rd Output
-
Voltage - Isolation
1.5kV (1500V)
Mounting Type
Through Hole
Package / Case
9-DIP Module, 1/2 Brick
Size / Dimension
2.40" L x 2.28" W x 0.50" H (61mm x 57.9mm x 12.7mm)
Operating Temperature
-40°C ~ 100°C
Efficiency
83%
Lead Free Status / Rohs Status
Lead free / RoHS Compliant
Other names
102-2250
Q5887922
Q5990267
VHB75W-Q24-S12
Q5887922
Q5990267
VHB75W-Q24-S12
PART NUMBER: VHB75W
APPLICATION NOTES
1. OUTPUT DE-RATING
The operating case temperature range for VHB75W is -40 ~ +100°C. When operating the VHB75W series, proper derating or cooling
is needed. The maximum case temperature under any operating condition should not exceed 100°C.
Example:
Solution:
Determine Power dissipation (Pd):
Determine airflow:
Check above Power de-rating curve:
Verifying:
Where:
What is the minimum airflow necessary for a VHB75W-Q48-S12
operating at nominal line, an output current of 6.25 A, and a
maximum ambient temperature of 40°C?
Given: Vin=48 V dc, Vo=12 V dc, Io=6.25 A
Pd=Pi-Po=Po(1-η)/η
Pd=12×6.25×(1-0.84)/0.84=14.29 W
Given: Pd=14.29 W and Ta=40°C
minimum airflow= 400 ft./min.
The maximum temp. rise ΔT = Pd × Rca=14.29×3.64=52.02°C. The maximum case temperature Tc=Ta+ΔT=92.02°C<100°C
The Rca is thermal resistance from case to ambience.The Ta is ambient temperature and the Tc is case temperature.
20050 SW 112
Power Dissipated vs Ambient Temperature and Air Flo w
th
Ave. Tualatin, Oregon 97062
FIGURE 1. OUTPUT DERATING (FORCED CONVECTION WITH NO HEAT SINK)
Ambient Temperature ,Ta(Deg. C)
phone
phone 503.612.2300 fax
DESCRIPTION: half-brick dc-dc converter
fax 503.612.2383
Chart of Thermal Resistance vs Air Flow
AIR FLOW RATE
Natural Convection
20ft./min. (0.1m/s)
100 ft./min. (0.5m/s)
200 ft./min. (1.0m/s)
300 ft./min. (1.5m/s)
400 ft./min. (2.0m/s)
500 ft./min. (2.5m/s)
600 ft./min. (3.0m/s)
700 ft./min. (3.5m/s)
800 ft./min. (4.0m/s)
Natural Convection
20 ft./min. (0.1 m/s)
100 ft./min. (0.5 m/s)
200 ft./min. (1.0 m/s)
300 ft./min. (1.5 m/s)
400 ft./min. (2.0 m/s)
500 ft./min. (2.5 m/s)
600 ft./min. (3.0 m/s)
700 ft./min. (3.5 m/s)
800 ft./min. (4.0 m/s)
www.v-infinity.com
page
date
TYPICAL Rca
7.12
6.21
5.17
4.29
3.64
2.96
2.53
2.37
2.19
04/2011
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