LM56 Datasheet | National Semiconductor

Description The LM56 is a precision low power thermostat. Two stable temperature trip points (VT1 and VT2) are generated by dividing down the LM56 1.250V bandgap voltage reference using 3 external resistors. The LM56 has two digital outputs. OUT1 goes LOW when the temperature exceeds T1 and goes HIGH when the the temperature goes below (T1- THYST). Similarly, OUT2 goes LOW when the temperature exceeds T2 and goes HIGH when the temperature goes below (T2- THYST). THYST is an internally set 5˚C typical hysteresis. The LM56 is available in an 8-lead Mini-SO8 surface mount package and an 8-lead small outline package. Features n n n n n n Digital outputs support TTL logic levels Internal temperature sensor 2 internal parators with hysteresis Internal voltage reference Currently available in 8-pin SO plastic package Future availability in the 8-pin Mini-SO8 package Key Specifications n Power Supply Voltage n Power Supply Current n VREF n Hysteresis Temperature n Internal Temperature Sensor Output Voltage (+6.20 m V/˚C x T) +395 m V n Temperature Trip Point Accuracy: LM56BIM +25˚C +25˚C to +85˚C - 40˚C to +125˚C LM56CIM 2.7V- 10V 230 µA (max) 1.250V ± 1% (max) 5˚C Applications n n n n n n n n Microprocessor Thermal Management Appliances Portable Battery Powered 3.0V or 5V Systems Fan Control Industrial Process Control HVAC Systems Remote Temperature Sensing Electronic System Protection ± 2˚C (max) ± 2˚C (max) ± 3˚C (max) ± 3˚C (max) ± 3˚C (max) ± 4˚C (max) Simplified Block Diagram and Connection Diagram DS012893-2 DS012893-1 Order Number NS Package Number Transport Media Package Marking LM56BIM LM56BIMX M08A SOP-8 M08A SOP-8 2500 Units Rail LM56BIM Tape & Reel LM56BIM LM56CIM LM56CIMX M08A SOP-8 M08A SOP-8 2500 Units Rail LM56CIM Tape & Reel LM56CIM LM56BIMM MUA08A MSOP-8 LM56BIMMX MUA08A MSOP-8 3500 Units LM56CIMM MUA08A MSOP-8 LM56CIMMX MUA08A MSOP-8 3500 Units Rail T02B Tape & Reel T02B Rail T02C Tape & Reel T02C © 2000 National Semiconductor...