LT3055 Series 500mA, Linear Regulator with Precision Current Limit and Diagnostics FEATURESDESCRIPTION n Output Current: 500mA The LT®3055 series are micropower, low noise, low dropout n Dropout Voltage: 350mV voltage (LDO) linear regulators. The devices supply 500mA n Input Voltage Range: 1.6V to 45V of output current with a dropout voltage of 350mV. A 10nF n Programmable Precision Current Limit: ±10% bypass capacitor reduces output noise to 25μVRMS in a n Output Current Monitor: 1/500th of IOUT 10Hz to 100kHz bandwidth and soft starts the reference. n Programmable Minimum IOUT Monitor The LT3055’s ±45V input voltage rating combined with its n Temperature Monitor: 10mV/°C precision current limit and diagnostic functions make the n FAULT Indicator: Current Limit, Thermal Limit or IC an ideal choice for robust, high reliability applications. Minimum IOUT A single resistor programs the LT3055’s current limit, ac- n Low Noise: 25μVRMS (10Hz to 100kHz) curate to ±10% over a wide input voltage and temperature n Adjustable Output (VREF = VOUT(MIN) = 0.6V) range. Another resistor programs the LT3055’s minimum n Output Tolerance: ±2% Over Load, Line and Temperature output current monitor, useful for detecting open-circuit n Stable with Low ESR, Ceramic Output Capacitors conditions. The current monitor function sources a current (3.3μF Minimum) equal to 1/500th of output current. Logic fault pins assert n Shutdown Current: <1μA low if the LT3055 is in current limit (FAULT2), operating n Reverse Battery and Thermal Limit Protection below its minimum output current (FAULT1) or is in thermal n 16-Lead 4mm × 3mm DFN and MSOP Packages limit (both FAULT1 and FAULT2). PWRGD indicates output regulation. The TEMP pin indicates average die temperature. APPLICATIONS n The LT3055 optimizes stability and transient response Protected Antenna Supplies n with low ESR ceramic capacitors, requiring a minimum of Automotive Telematics n 3.3μF. Internal protection circuitry includes current limit- Industrial Applications (Trucks, Forklifts, etc.) n ing, thermal limiting, reverse battery protection, reverse High Reliability Applications n current protection and reverse output protection. Noise-Sensitive RF or DSP Supplies All registered trademarks and trademarks are the property of their respective owners. The LT3055 is available in fixed output voltages of 3.3V and 5V, and as an adjustable device with an output voltage range from 0.6V to 40V. TYPICAL APPLICATIONPrecision Current Limit, RIMAX = 604Ω5V Supply with 497mA Precision Current Limit, 10mA I 550 MIN VOUT(NOMINAL) = 5V 540 LT3055-5 530 + IN OUT 5V VIN 520 10µF 200k 200k 200k SHDN SENSE 10nF 10µF 6V 510 FAULT1 VIN = 7V FAULT2 ADJ 500 PWRGD TO 490 VIN = 5.6V IMAX IMON µP 1k 480 604Ω ADC 22nF (ADC 0.1µF (THRESHOLD = 497mA) 470 FULL-SCALE = 1V) TO 460 TEMP µP CURRENT LIMIT FAULT THRESHOLD (mA) I 450 MIN REF/BYP ADC –75 –50 –25 0 25 50 75 100 125 150 175 120k GND 0.1µF 10nF (THRESHOLD = 10mA) TEMPERATURE (°C) 3055 TA01a 3055 TA01b Rev. B Document Feedback For more information www.analog.com 1 Document Outline Features Applications Description Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Package Description Revision History Typical Application Related Parts