Instruction Manual

GE
Data Sheet
SHHD003A0A Hammerhead Series; DC-DC Converter Power Modules
18-75Vdc Input; 5.0Vdc, 3A, 15W Output
June 26, 2013 ©2012 General Electric Company. All rights reserved. Page 8
Feature Descriptions (continued)
Vout+
TRIM
Vout-
R
adj-up
R
LOAD
Vin+
ON/OFF
Vin-
Figure 12. Circuit Configuration to Increase Output Voltage.
The SHHD power modules have a fixed current-limit set point.
Therefore, as the output voltage is adjusted down, the
available output power is reduced.
Trim Examples
For SHHD003A0A, nominal 5.0V module. To trim module down
to 4.90V:











 2050
)9.40.5(
5110)5.29.4(
downadj R
 590,120downadjR
Thermal Considerations
The power modules operate in a variety of thermal
environments; however, sufficient cooling should be provided
to help ensure reliable operation.
Considerations include ambient temperature, airflow, module
power dissipation, and the need for increased reliability. A
reduction in the operating temperature of the module will
result in an increase in reliability.
The thermal data presented here is based on physical
measurements taken in a wind tunnel, using automated
thermo-couple instrumentation to monitor key component
temperatures: FETs, diodes, control ICs, magnetic cores,
ceramic capacitors, opto-isolators, and module pwb
conductors, while controlling the ambient airflow rate and
temperature. For a given airflow and ambient temperature, the
module output power is increased, until one (or more) of the
components reaches its maximum derated operating
temperature, as defined in IPC-9592A. This procedure is then
repeated for a different airflow or ambient temperature until a
family of module output derating curves is obtained.
Figure 13. Thermal Test Setup .
OUTPUT CURRENT, I
O
(A)
LOCAL AMBIENT TEMPERATURE, T
A
(C)
Figure 14. Output Current Derating for the Open Frame
SHHD003A0A in the Transverse Orientation; Airflow
Direction from Vin(-) to Vin(+); Vin = 24V.
OUTPUT CURRENT, I
O
(A)
LOCAL AMBIENT TEMPERATURE, T
A
(C)
Figure 15. Output Current Derating for the Open Frame
SHHD003A0A in the Transverse Orientation; Airflow
Direction from Vin(-) to Vin(+); Vin = 48V.
The thermal reference point, T
ref
used in the specifications is
shown in Figure 16. For reliable operation this temperature
should not exceed 111
o
C.