DC/DC Converter
WRA_S-1WR2 & WRB_S-1WR2 Series
2017.08.17-B/1 Page 5 of 6
MORNSUN Guangzhou Science & Technology Co., Ltd. reserves the copyright and right of final interpretation
Notes:
①Part ①in Fig. 3 is used for EMS test while part ②is used for EMI filtering; and parts ①and ②may be selected based on needs.
②VCis the voltage of the Ctrl end relative to the GND of the input grounding; VDis the positive-going conduction pressure drop of D1; ICis the current flows
into the Ctrl end and its value is generally 5-10mA, see Fig. 3-③for the peripheral circuit of Ctrl end;
③If there is no recommended parameters, no external component is required.
The modules are of normal output when the Ctrl end is suspended or of high resistance; the modules turn off when connecting with high
level (relative to the input grounding); notice that the current flows into the pin shall be 5 - 10mA, the modules will be permanently damaged
if the current exceeds its max. value (20mA in general).
The value of R can be derived as follows:
For Detailed parameter, please refer to EMC solution-recommended circuit in this manual.
When the electricity is provided by the unstable power supply, please make sure that the range of the output voltage fluctuation and the
ripple voltage of the power supply do not exceed the indicators of the modules. Input current of power supply should afford the flash startup
current of this kind of DC/DC module(see Fig. 5).
Generally: Vin= 5V series Iave =445mA
Vin=12V series lave =205mA
Vin=24V series lave =104mA
Vin=48V series lave =53mA
Input Current(A)
Input Voltage (V)
Input Voltage
scope
Iave
5. Output load requirements
When using, the minimum load of the module output should not be less than 5% of the nominal load.In order to meet the performance
parameters of this datasheet, please connect a 5% dummy load in parallel at the output end, the dummy load is generally a resistor, please
note that the resistor needs to be used in derating.
6. For more information please find DC-DC converter application notes on www.mornsun-power.com