Inrush Current - TDK-Lambda ZWS-B Series Instruction Manual

4-3. Inrush Current

This series equipped Power thermistor to limit the inrush current. Higher inrush current will flow at higher ambient temperature or re-input
condition. Please select input switch and fuse carefully with the high temperature and re-input the power condition. The Inrush Current value
is under cold start at 25℃ in the specification.
4-4. Over Voltage Protection (OVP)
The OVP function (Inverter shut down method, manual reset type) is provided. Please refer to its specification for OVP operating range.
When OVP trigger, the output will be shut down. To reset OVP, remove the input of power supply for a few minutes, and then re-input. In
addition, the setting value of OVP is fixed and not adjustable. Pay attention not to apply higher voltage externally to the output terminal to
avoid unit failure. In case of inductive load, put protective diode in series to the output power line.
4-5. Over Current Protection (OCP)
ZWS10B, ZWS15B, ZWS30B: Hiccup mode with automatic recovery.
OCP function operates when the output current exceeds 105% of maximum DC output current of specification. The outputs will be
automatically recovered when the overload condition is canceled. Never operate the unit under over current or shorted conditions for more
than 30seconds, which may leads damage or insulation failure. OCP setting is fixed and not to be adjusted externally.
4-6. Output Ripple & Noise
The standard specification for maximum ripple value is measured according to measurement circuit specified by JEITA-RC9131B. When
load lines are longer, ripple will becomes larger. In this case, electrolytic capacitor, film capacitor, etc. might be necessary to use across the
load terminal. The output ripple cannot be measured accurately if the probe ground lead of oscilloscope is too long. For start up at low
ambient temperature and low input voltage, output ripple noise might not meet specification. However, output ripple noise specification can
be met after one second.
A circuit reducing light load input power consumption is built in ZWS10B, ZWS15B, ZWS30B (Input power : 0.2W typ, 0.5W max at no
load). When output current is within 0-35% of rated load, the internal switch element is intermittent operated, and the switching loss is
decreased. The specification of the Ripple & Noise changes by this intermittent operation. The dynamic load response characteristic changes
by this intermittent operation too. Different input voltage and dynamic load condition has different dynamic load response characteristic.
Please contact us for details.
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Power
Supply
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4-7. Series Operation
For series operation, either method (A) or (B) is possible.
(A)
Power Supply
Output
Terminal
Output
Terminal
(*1)Please select a bypass diode with maximum forward current rating more than output load current. And maximum reverse voltage must
withstand each power supply output voltage.
150mm
A
C1 Load
C2
Coaxial Cable
1.5m 50Ω
Load
(*1)
C1 : 0.1uF Film Cap.
C2 : 100uF Electric Cap.
C3 : 4700uF Ceramic Cap. C3 : 4700pF Ceramic Cap.
R1 : 50Ω
Oscilloscope
Bandwidth : 100MHz
R1
C3
(B)
Power Supply
Output
Terminal
Output
Terminal
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TDK-Lambda
ZWS10・15B・30B Series
Instruction Manual
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