YS12S16 DC-DC Converter
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BCD.00645_AA
Overtemperature Protection (OTP)
The converter will shut down under an over-temperature condition to protect itself from overheating caused by
operation outside the thermal derating curves, or operation in abnormal conditions such as system fan failure. After
the converter has cooled to a safe operating temperature, it will automatically restart.
Safety Requirements
The converter meets North American and International safety regulatory requirements per UL60950 and EN60950.
The maximum DC voltage between any two pins is Vin under all operating conditions. Therefore, the unit has ELV
(extra low voltage) output; it meets SELV requirements under the condition that all input voltages are ELV.
The converter is not internally fused. To comply with safety agencies requirements, a recognized fuse with a
maximum rating of 15 Amps must be used in series with the input line.
General Information
The converter has been characterized for many operational aspects, to include thermal derating (maximum load
current as a function of ambient temperature and airflow) for vertical mounting, efficiency, start-up and shutdown
parameters, output ripple and noise, transient response to load step-change, overload and short circuit.
The figures are numbered as Fig. x.y, where x indicates the different output voltages, and y associates with specific
plots (y = 1 for the vertical thermal derating, …). For example, Fig. x.1 will refer to the vertical thermal derating for all
the output voltages in general.
The following pages contain specific plots or waveforms associated with the converter. Additional comments for
specific data are provided below.
Test Conditions
All data presented were taken with the converter soldered to a test board, specifically a 0.060” thick printed wiring
board (PWB) with four layers. The top and bottom layers were not metalized. The two inner layers, comprising two-
ounce copper, were used to provide traces for connectivity to the converter.
The lack of metalization on the outer layers as well as the limited thermal connection ensured that heat transfer from
the converter to the PWB was minimized. This provides a worst-case but consistent scenario for thermal derating
purposes.
All measurements requiring airflow were made in the vertical and horizontal wind tunnel facilities using Infrared (IR)
thermography and thermocouples for thermometry.
Ensuring components on the converter do not exceed their ratings is important to maintaining high reliability. If one
anticipates operating the converter at or close to the maximum loads specified in the derating curves, it is prudent to
check actual operating temperatures in the application. Thermographic imaging is preferable; if this capability is not
available, then thermocouples may be used. . It is recommended the use of AWG #40 gauge thermocouples to
ensure measurement accuracy. Careful routing of the thermocouple leads will further minimize measurement error.
Refer to Fig. D for optimum measuring thermocouple locations.
Fig. D: Location of the thermocouple for thermal testing.