VHB50W-Q24-S15 CUI Inc, VHB50W-Q24-S15 Datasheet - Page 4

• Manufacturer Part Number: VHB50W-Q24-S15
• Description: CONVERTER DC/DC 9-36V INPUT 50W
• Manufacturer: CUI Inc
• Series: V-Infinity VHB50Wr
• Type: Isolatedr

Specifications of VHB50W-Q24-S15

• Output: 15V
• Number Of Outputs: 1
• Power (watts): 50W
• Mounting Type: Through Hole
• Voltage - Input: 9 ~ 36V
• Package / Case: 9-DIP Module
• 1st Output: 15 VDC @ 3.33A
• Size / Dimension: 2.40" L x 2.28" W x 0.50" H (61mm x 57.9mm x 12.7mm)
• Power (watts) - Rated: 50W
• Operating Temperature: -40°C ~ 100°C
• Efficiency: 83%
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• 3rd Output: -
• 2nd Output: -
• 4th Output: -
• Other names: 102-1568

PART NUMBER: VHB50W
APPLICATION NOTES
1. OUTPUT DE-RATING
The operating case temperature range for VHB50W is -40 ~ +100°C. When operating the VHB50W 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 VHB50W-Q48-S12
operating at nominal line, an output current of 4.16 A, and a
maximum ambient temperature of 60°C?
Given: Vin=48 V dc, Vo=12 V dc, Io=4.16 A
Pd=Pi-Po=Po(1-η)/η
Pd=12×4.16×(1-0.84)/0.84=9.51 W
Given: Pd=9.51 W and Ta=60°C
minimum airflow= 400 ft./min.
The maximum temp. rise ΔT = Pd × Rca=9.51×3.64=34.6°C. The maximum case temperature Tc=Ta+ΔT=94.6°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
FIGURE 1. OUTPUT DERATING (FORCED CONVECTION WITH NO HEAT SINK)
th
Ambient Temperature ,Ta(Deg. C)
Ave. Tualatin, Oregon 97062
phone
phone [phone] fax
DESCRIPTION: half-brick dc-dc converter
fax [phone]
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)
page
date
TYPICAL Rca
7.12
6.21
5.17
4.29
3.64
2.96
2.53
2.37
2.19
06/2009
4 of 11
/W
/W
/W
/W
/W
/W
/W
/W
/W