Datasheet LT1970A (Analog Devices)

LT1970A 500mA Power Op Amp with Adjustable Precision Current Limit
FeaTures DescripTion
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 (VCC to V+ and VEE to V–). To reduce 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/µs Slew Rate and slews at 1.6V/µs. The LT1970A can drive capacitive n 3.6MHz Gain-Bandwidth Product and inductive loads directly. n Specified Temperature Range: –40°C to 85°C n Available in a 20-Lead TSSOP Package Open-collector status flags signal current limit circuit activation, as well as thermal shutdown of the amplifier.
applicaTions
An enable logic input puts the amplifier into a low power, n high impedance output state when pulled low. Thermal Automatic Test Equipment n shutdown and a ±800mA fixed current limit protect the Laboratory Power Supplies n chip under fault conditions. 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 applicaTion Device Power Supply (DPS) with ±500mA Adjustable Current Limit
VLIMIT 0V TO 5V 20V 20V CURRENT LIMIT = 500mA 6k VCC V V+ LIMIT IOUT(MAX) = ±10 • R V CS LOAD, RLOAD = 100Ω ENVC I VIN +IN SRC OUT VCSNKISNK RCS 1Ω TRACE R TRACE L VLOAD, ISRC 1/4W 100mΩ 200nH 2V/DIV R TSD LOAD = 10Ω LT1970A OUT SENSE+ 4.7µF VIN, 5V/DIV SENSE– SENSE LOAD ESR V– –IN V 0.1Ω EE 0V COMMON 1970A TA01 100µs/DIV –5V 10k 1970A TA01b 100pF 1970afc For more information www.linear.com/LT1970A 1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram And Test Circuit Applications Information Package Description Applications Information Related Parts