※Contact TDK-Lambda concerning items not mentioned or items which are not clear.
4-4 Over-Current Protection (OCP) & Low-Voltage Protection (LVP)
These converters are equipped with built-in over-current protection and low-voltage protection circuits.
When the output current exceeds the over-current setting point the over-current protection circuit operates and the output
voltage begins to fall. When the output voltage falls below 90% of the rated voltage, the low-voltage protection circuit
operates and shuts down the output.
There is a time lag of approx. 100 ms from the time the LVP circuit detects an abnormality until the output is shut down.
When the output shuts down, the Alarm signal operates.
When the output shuts down and operation stops, after the cause of the over-current or low-voltage is removed, recovery
can be achieved either by restarting the input power source or by using the remote control function.
4-5 Over-Voltage Protection
These converters are equipped with a built-in over-voltage protection circuit.
When the output voltage becomes 115%～145% of the rated voltage, the over-voltage protection circuit operates.
When the output current is less than 50% of the rated current, depending on the failure mode, operation at voltage exceeding
the upper limit may occur.
When the output shuts down, the Alarm signal operates.
When the output shuts down and operation stops, after the cause of the over-current or low-voltage is removed, recovery
can be achieved either by restarting the input power source or by using the remote control function.
4-6 Operation Sequence
The input voltage, output voltage, RC, PO, ALM terminal operation sequence of these converters is shown in Figure 4-6.
RC：OFF
RC：ON
Vin
20～50ms
Start-up
LVP set
Vout
PO
ALM
RC
OCP set
100ms typ
ALM set
ALM reset
Fig. 4-6 Sequence Chart
