Rev. 04.25.11

SIL/SMT80C2

3 of 20

Embedded Power for

Business-Critical Continuity

Technical Reference Note

Output Voltage Adjustment

Theoutputvoltageonallmodelsisadjustablefrom0.8375-5.1V.

Undervoltage Lockout

Thedefaultundervoltagelockoutissetat4.7V.

Current Limit and Short-Circuit Protection

TheSIL/SMT80C2modelhasabuilt-innon-latchingcurrentlimitfunctionandcontinuousshort-circuit

protection.Whenanovercurrentconditionoccurs,themodulegoesintohiccupmode,whereitattempts

topowerupperiodicallytodetermineiftheproblempersists.

Notethatnoneofthemodulespecificationsareguaranteedwhentheunitisoperatedinanovercurrent

condition.

Enable

TheenablepinallowsexternalcircuitrytoputtheSIL/SMT80C2converterintoalowdissipationstandby

mode. Positive logic enable pin is available as standard.

Theunitisturnedoniftheenablepinishigh(orfloating).Pullingthepinlowwilldisabletheunit.To

guaranteeturn-on,theenablevoltagemustbeabove1.25V. Todisable,theenablevoltagemustbe

pulled below 0.7 V.

Figures3and4showvariouscircuitsfordrivingtheEnablefeature.TheEnableinputcanbedriven

throughadiscretedevice(i.e.abipolarsignaltransistor)ordirectlyfromalogicgateoutput.Theoutput

ofthelogicgatemaybeanopen-collector(oropen-drain)device.

Features and Functions

Figure 3 - Enable Input Drive Circuit for Non-Isolated Biopolar

SIL80C2

Ground

Trim

Vin

Enable

Vout

5 V

SIL80C2

Ground

Trim

Vin

Enable

Vout

Figure 4 - Enable Input Drive Circuit for Logic Driver