Features Descriptions

Over-Current Protection

The modules include an internal output over-current protection circuit, which will endure current limiting for an unlimited duration during output overload. If the output current exceeds the OCP set point, the modules will automatically shut down and latch off.

Over-Voltage Protection

The modules include an internal output over-voltage protection circuit, which monitors the voltage on the output terminals. If this voltage exceeds the over- voltage set point, the module will shut down and latch off. Cycling the input power for one second can reset the over-voltage latch.

Over-Temperature Protection

The over-temperature protection consists of circuitry that provides protection from thermal damage. If the temperature exceeds the over-temperature threshold the module will shut down.

The module will try to restart after shutdown. If the over- temperature condition still exists during restart, the module will shut down again. This restart trial will continue until the temperature is within specification.

Remote On/Off

The remote on/off feature on the module can be either negative or positive logic. Negative logic turns the module on during a logic low and off during a logic high. Positive logic turns the modules on during a logic high and off during a logic low.

Remote on/off can be controlled by an external switch between the on/off terminal and the Vi(-) terminal. The switch can be an open collector or open drain.

For negative logic if the remote on/off feature is not used, please short the on/off pin to Vi(-). For positive logic if the remote on/off feature is not used, please leave the on/off pin floating.

DS_Q48SP12017_05302008

Vi(+)	Vo(+)
	Sense(+)
ON/OFF
	Sense(-)
Vi(-)	Vo(-)

Figure 15: Remote on/off implementation

Remote Sense

(Not applicable to Q48SP120017Exxx)

Remote sense compensates for voltage drops on the output by sensing the actual output voltage at the point of load. The voltage between the remote sense pins and the output terminals must not exceed the output voltage sense range given here:

[Vo(+) – Vo(–)] – [SENSE(+) – SENSE(–)] ≤ 0.5V

This limit includes any increase in voltage due to remote sense compensation and output voltage set point adjustment (trim).

Vi(+)	Vo(+)
Sense(+)
	Sense(-)
Vi(-) Vo(-)
Contact	Contact and Distribution
Resistance	Losses
Figure 16: Effective circuit configuration for remote sense
operation

If the remote sense feature is not used to regulate the output at the point of load, please connect SENSE(+) to Vo(+) and SENSE(–) to Vo(–) at the module.

The output voltage can be increased by both the remote sense and the trim; however, the maximum allowed increase is the larger of either the remote sense spec or the trim spec, not the sum of both.

When using remote sense and trim, the output voltage of the module is usually increased, which increases the power output of the module with the same output current.

Care should be taken to ensure that the maximum output power does not exceed the maximum rated power.