LP3985 100mA,Ultra-LowNoise Ultra-fast CMOS LDO Regrlator General Description The LP3985 is designed for portable RF and wireless applications with demanding performance and space requirements. The LP3985 performance is optimized for battery-powered systems to deliver ultra low noise and low quiescent current. A noise bypass pin is available for further reduction of output noise. Regulator ground current increases only slightly in dropout, further prolonging the battery life. The LP3985 also works with low-ESR ceramic capacitors, reducing the amount of board space necessary for power applications, critical in hand-held wireless devices. The LP3985 consumes less than 0.01µA in shutdown mode and has fast turn-on time less than 50µs. The other features include ultra low dropout voltage, high output accuracy, current limiting protection, and high ripple rejection ratio. Available in the 5-lead of SOT-23 packages. Features Ultra-Low-Noise for RF Application 2.5V- 6V Input Voltage Range Low Dropout : 450mV @ 100mA High PSSR:-70dB at 1KHz < 0.01 A Standby Current When Shutdown TTL-Logic-Controlled Shutdown Input Custom Voltage Available Ultra-Fast Response in Line/Load Transient Quick Start-Up (Typically 50 s) Current Limiting and Thermal Shutdown Protection Applications PMP/PDA/MP3 players Cellular and Mobile phone DSC RF Module Sensor Module Pin Configurations Ordering Information LP3985 - □ □ □ □ □ F:PB-Free Package Type B3: SOT-23 Output Voltage: 15: 1.5V 18: 1.8V SOT-23 Typical Application Circuit 33: 3.3V Note: 1. Output Voltage range from 1.5V to 3.3V in 0.1V increments. 2. 1.8V output order is LP3985-185B3F. LP3985-datasheet Oct.-2003 1-8 LP3985 Functional Pin Description Pin Name Pin Function GND Ground VOUT VIN Output Voltage Power Input Voltage Function Block Diagram Absolute Maximum Ratings Supply Input Voltage------------------------------------------------------------------------------------------------------6V Power Dissipation, PD @ TA = 25°C SOT-23 --------------------------------------------------------------------------------------------------------------------400mW Package Thermal Resistance SOT-23, θJA -------------------------------------------------------------------------------------------------------------250°C/W Lead Temperature (Soldering, 10 sec.) -------------------------------------------------------------------------------260°C Storage Temperature Range --------------------------------------------------------------------------------−65°C to 150°C ESD Susceptibility HBM (Human Body Mode) ---------------------------------------------------------------------------------------------2kV MM(Machine-Mode)-----------------------------------------------------------------------------------------------------200V Recommended Operating Conditions Supply Input Voltage-----------------------------------------------------------------------------2.5V to 5.5V EN Input Voltage -------------------------------------------------------------------------------------0V to 5.5V Operation Junction Temperature Range ---------------------------------------------−40°C to 125°C Operation Ambient Temperature Range------------------------------------------------−40°C to 85°C LP3985-datasheet Oct.-2003 2-8 LP3985 Electrical Characteristics (VIN = VOUT + 1V, CIN = COUT = 1µF, CBP = 22nF, TA = 25° C, unless otherwise specified) Parameter Symbol Test Conditions Min Typ Max Units +2 % Output Voltage Accuracy ΔVOUT IOUT = 1mA −2 -- Current Limit ILIM RLOAD = 1Ω 360 400 Quiescent Current IQ VEN ≥ 1.2V, IOUT = 0mA Dropout Voltage VDROP Line Regulation ΔVLINE 90 130 IOUT = 200mA, VOUT > 2.8V 170 200 IOUT = 300mA, VOUT > 2.8V 220 300 VIN = (VOUT + 1V) to 5.5V, VLOAD 1mA < IOUT < 300mA Standby Current ISTBY VEN = GND, Shutdown EN Input Bias Current IIBSD VEN = GND or VIN Logic-Low EN Threshold Voltage VIL Output Noise Voltage eNO Power Supply f = 100Hz Rejection Rate f= 10kHz Thermal Shutdown Temperature LP3985-datasheet VIH Oct.-2003 mV % 0.6 % 0.01 1 μA 0 100 nA VIN = 3V to 5.5V, 0.4 Shutdown V Logic-High Voltage μA 0.3 IOUT = 1mA Δ Load Regulation mA VIN = 3V to 5.5V, Start-Up 10Hz to 100kHz, IOUT = 200mA COUT = 1µF PSRR 1.2 100 μ VRMS −70 COUT = 1µF, IOUT = 10mA TSD −50 165 3-8 dB °C