LTC3025-1/LTC3025-2/ LTC3025-3/LTC3025-4 500mA Micropower VLDO Linear Regulators FeaTuresDescripTion n Wide Input Voltage Range: 0.9V to 5.5V The LTC®3025-X is a micropower, VLDO™ (very low drop- n Stable with Ceramic Capacitors out) linear regulator which operates from input voltages as n Very Low Dropout: 85mV at 500mA low as 0.9V. The device is capable of supplying 500mA of n Adjustable Output Range: 0.4V to 3.6V (LTC3025-1) output current with a typical dropout voltage of only 85mV. n Fixed Output: 1.2V (LTC3025-2), 1.5V (LTC3025-3), A BIAS supply is required to run the internal reference and 1.8V (LTC3025-4) LDO circuitry while output current comes directly from the n ±2% Voltage Accuracy over Temperature, IN supply for high efficiency regulation. The LTC3025-1 Supply and Load features an adjustable output with a low 0.4V reference n Low Noise: 80µVRMS (10Hz to 100kHz) while the LTC3025-2, LTC3025-3, and LTC3025-4 have n BIAS Voltage Range: 2.5V to 5.5V fixed 1.2V, 1.5V and 1.8V output voltages respectively. n Fast Transient Recovery The LTC3025-X’s low quiescent current makes it an ideal n Shutdown Disconnects Load from VIN and VBIAS choice for use in battery-powered systems. For 3-cell NiMH n Low Operating Current: IIN = 4µA, IBIAS = 50µA Typ and single cell Li-Ion applications, the BIAS voltage can n Low Shutdown Current: IIN = 1µA, IBIAS = 0.01µA Typ be supplied directly from the battery while the input can n Output Current Limit come from a high efficiency buck regulator, providing a n Thermal Overload Protection high efficiency, low noise output. n Available in 6-Lead (2mm × 2mm) DFN Package Other features include high output voltage accuracy, applicaTions excellent transient response, stability with ultralow ESR ceramic capacitors as small as 1µF, short-circuit and n Low Power Handheld Devices thermal overload protection and output current limiting. n Low Voltage Logic Supplies The LTC3025-X is available in a tiny, low profile (0.75mm) n DSP Power Supplies 6-lead DFN (2mm × 2mm) package. n Cellular Phones L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and VLDO n Portable Electronic Equipment and ThinSOT are trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 7224204, 7218082. n Handheld Medical Instruments n Post Regulator for Switching Supply Noise Rejection Typical applicaTion1MHz VIN Supply Rejection1.2V Output Voltage from 1.5V Input Supply 50 45 COUT = 10µF BIAS OUT VOUT = 1.2V I 40 0.1µF 1µF OUT ≤ 500mA Li-Ion 1.5V HIGH LTC3025-2 35 C OR EFFICIENCY OUT = 1µF 1.5V 3-CELL DC/DC IN SENSE 30 NiMH BUCK 0.1µF 25 20 OFF ON SHDN GND REJECTION (dB) 15 30251234 TA01 10 5 BIAS = 3.6V IOUT = 100mA VOUT = 1.2V IOUT = 300mA 01.2 1.4 1.6 1.8 2.0 2.2 2.4 2.6 VIN (V) 30251234 TA01b 30251234ff 1 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Applications Information Package Description Revision History Typical Application Related Parts