Vicor ComPAC Family 50 to 600 Watt DC-DC Switchers - Manual (Page 3)

3
+ V
OUT
To Load
— V
OUT
R1
10K
R2
+ OUT
+ SENSE
TRIM
— SENSE
— OUT
Resistor Values for Trimming Standard Output Voltages
Nominal Output Voltage 5 V 12 V 15 V 24 V 28 V 48 V Trim Range
R1(KΩ) .953 15.8 22.1 41.2 48.7 90.9
R2(KΩ) 90 90 90 90 90 90
+10%, -10%
Refer to Applications Manual, Chapter 5, for other trimming methods.
Output Trimming
Note: Not applicable for conduction cooled (–CC) models.
Below are the chassis-to-air thermal impedance values, as a function of airflow,
for ComPAC package configurations that incorporate one, two, and three internal
component DC-DC converters.
Thermal Impedance—Case-to-Air (°C/Watt)
Standard Units With Optional H1 Heatsink
1-Up 2-Up 3-Up 1-Up 2-Up 3-Up
Free Air (Horiz.) 3.6 1.7 1.4 2.1 1.3 1.0
Forced Convection Through Heat sink Fins
50 LFM 2.7 1.4 1.3 1.5 1.1 0.9
100 LFM 2.3 1.3 1.1 1.2 0.9 0.7
250 LFM 1.6 1.0 0.8 0.7 0.5 0.4
500 LFM 1.2 0.7 0.6 0.4 0.3 0.3
750 LFM 0.9 0.5 0.5 0.3 0.2 0.2
1000 LFM 0.8 0.5 0.4 0.2 0.2 0.2
To calculate case temperature: total power dissipated times
thermal impedance plus ambient temperature.
To calculate Watts dissipated per output: output power
divided by efficiency minus output power.
Thermal Impedance
Trim resistors not required for operation at rated output voltage.
+Sense and –Sense must be connected locally or remotely (shown).