LT1970A 500mA Power Op Amp with Adjustable Precision Current Limit Fea T Descrip T n 500mA Minimum Output Current The LT 1970A is a 500mA power op amp with precise n Independent Adjustment of Source and externally controlled current limiting. Separate control Sink Current Limits voltages program the sourcing and sinking current limit n 1% Current Limit Accuracy sense thresholds with 1% accuracy. Output current may n Improved Reactive Load Driving Stability be boosted by adding external power transistors. n Operates with Single or Split Supplies The circuit operates with single or split power supplies n Shutdown/Enable Control Input from 5V to 36V total supply voltage. In normal opera- n Open-Collector Status Flags: tion, the input stage supplies and the output stage sup- Sink Current Limit + plies are connected (V to V and V to V ). To reduce CC EE Source Current Limit power dissipation it is possible to power the output stage Thermal Shutdown + (V , V ) from independent, lower voltage rails. The amplifier n Fail-Safe Current Limit and Thermal Shutdown is unity-gain stable with a 3.6MHz gain-bandwidth product n 1.6V/s Slew Rate and slews at 1.6V/s. The LT1970A can drive capacitive n 3.6MHz Gain-Bandwidth Product and inductive loads directly. n Specified Temperature Range: 40C to 85C n Open-collector status flags signal current limit circuit Available in a 20-Lead TSSOP Package activation, as well as thermal shutdown of the amplifier. a T An enable logic input puts the amplifier into a low power, high impedance output state when pulled low. Thermal n Automatic Test Equipment shutdown and a 800mA fixed current limit protect the n Laboratory Power Supplies chip under fault conditions. n Motor Drivers n Thermoelectric Cooler Driver The LT1970A is packaged in a 20-lead TSSOP package with L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear a thermally conductive copper bottom plate to facilitate Technology Corporation. All other trademarks are the property of their respective owners. heat sinking. Typical a T Device Power Supply (DPS) with 500mA Adjustable Current Limit V LIMIT 0V TO 5V 20V 20V CURRENT LIMIT = 500mA 6k V CC V LIMIT + I = V OUT(MAX) 10 R V , R = 100 LOAD LOAD CS EN I OUT VC SRC V +IN IN VC SNK R CS ISNK TRACE R TRACE L V , 1 LOAD ISRC 2V/DIV 100m 200nH R = 10 1/4W LOAD TSD LT1970A OUT + SENSE 4.7F V , 5V/DIV IN SENSE LOAD SENSE ESR V 0.1 IN V EE 0V COMMON 1970A TA01 100s/DIV 5V 10k 1970A TA01b 100pF 1970afc 1 For more information www.linear.com/LT1970A ion pplica ions pplica ion uresLT1970A a Te Maxi Mu M r a T p in c F T (Note 1) TOP VIEW Supply Voltage (V to V ) ..................................... 36V CC EE + V 1 20 V EE EE Positive High Current Supply (V ) ................... V to V CC + + V 2 19 V Negative High Current Supply(V ) ....................V to V 21 EE OUT 3 18 TSD + Amplifier Output (OUT) ..................................... V to V + SENSE 4 17 ISNK Current Sense Pins FILTER 5 16 ISRC + + (SENSE , SENSE , FILTER) ........................... V to V + SENSE 6 15 ENABLE Logic Outputs (ISRC, ISNK, TSD) ....... COMMON to V CC V 7 14 COMMON CC Input Voltage (IN, +IN) ............ V 0.3V to V + 36V EE EE IN 8 13 VC SRC Input Current......................................................... 10mA +IN 9 12 VC SNK Current Control Inputs V 10 11 V EE EE (VC , VC ) .............. COMMON to COMMON + 7V SRC SNK FE PACKAGE Enable Logic Input .............................. COMMON to V 20-LEAD PLASTIC TSSOP CC T = 150C, = 40C/W (NOTE 8) JMAX JA COMMON ....................................................... V to V EE CC EXPOSED PAD (PIN 21) IS CONNECTED TO V EE Output Short-Circuit Duration ......................... Indefinite Operating Temperature Range (Note 2)....40C to 85C Specified Temperature Range (Note 3) LT1970AC ................................................ 0C to 70C LT1970AI.............................................. 40C to 85C Maximum Junction Temperature.......................... 150C Storage Temperature Range ...................65C to 150C Lead Temperature (Soldering, 10 sec) .................. 300C o r Der i n F Ma T LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE LT1970ACFE PBF LT1970ACFE TRPBF LT1970AFE 20-Lead Plastic TSSOP 0C to 70C LT1970AIFE PBF LT1970AIFE TRPBF LT1970AFE 20-Lead Plastic TSSOP 40C to 85C Consult LTC Marketing for parts specified with wider operating temperature ranges. For more information on lead free part marking, go to: