OPA2376: Device failure mode and limitation.

Hi Miyano,

according to figure 11 of datasheet, 50mA into the output is the short-circuit current. According to figure 12, 1.75V will drop across the output transistor, resulting in a heat dissipation of 1.75V x 50mA = 87.5mW, giving a temperature rise of 171.2K/W x 87.5mW = 15K over the ambient. So I do not see a relevant temperature issue, even for longer periods of short-circuit.

Nevertheless, in high reliability applications it's no good idea to run the OPAmp for longer periods with the short-circuit current. The standard application for which the OPAmp is designed for is the linear operation, not a sustained short-circuit.

Personally, if the short-circuit is repeated over longer periods I would add a small current limiting resistor and limit the output current to let say 10...20mA. But that's my personal taste.

Can you show a schematic and tell more about your application?

Kai

Miyano,

It is not clear to me from your description whether you refer to op amp short-circuit protection (which happens when you short the output pin to a voltage source within the OPA2376 voltage supply rails) or you ask about a fault condition that would occur when you short the output to a voltage source above or below rails?

If this is the former case, the sinking short-circuit output current is limited about 50mA at 25 deg C - see below - and as Kai indicated, exposing the part to such condition for extended periods may affect device reliability.

On the other hand, if you refer to the latter case, where you short the output pin above positive supply voltage, the current flows through the ESD protection diodes and must be limited to 10mA or less - see below.

If you need further assistance, please show the schematic of the condition including supply voltages you use.