LP3881EMRX-1.8

LP3881 0.8A Fast-Response Ultra Low Dropout Linear Regulators June 2006 LP3881 0.8A Fast-Response Ultra Low Dropout Linear Regulators General Description The LP3881 is a high current, fast response regulator which can maintain output voltage regulation with minimum input to output voltage drop. Fabricated on a CMOS process, the device operates from two input voltages: Vbias provides voltage to drive the gate of the N-MOS power transistor, while Vin is the input voltage which supplies power to the load. The use of an external bias rail allows the part to operate from ultra low Vin voltages. Unlike bipolar regulators, the CMOS architecture consumes extremely low quiescent current at any output load current. The use of an N-MOS power transistor results in wide bandwidth, yet minimum external capacitance is required to maintain loop stability. The fast transient response of these devices makes them suitable for use in powering DSP, Microcontroller Core voltages and Switch Mode Power Supply post regulators. The parts are available in TO-220, TO-263 and PSOP-8 packages. Dropout Voltage: 75 mV (typ) @ 0.8A load current. Ground Pin Current: 3 mA (typ) at full load. Shutdown Current: 60 nA (typ) when S/D pin is low. Precision Output Voltage: 1.5% room temperature accuracy. Features n n n n n n n n Ultra low dropout voltage (75 mV @ 0.8A typ) Low ground pin current Load regulation of 0.04%/A 60 nA typical quiescent current in shutdown 1.5% output accuracy (25˚C) TO-220, TO-263 and PSOP-8 packages Over temperature/over current protection −40˚C to +125˚C junction temperature range Applications n n n n n n n DSP Power Supplies Server Core and I/O Supplies PC Add-in-Cards Local Regulators in Set-Top Boxes Microcontroller Power Supplies High Efficiency Power Supplies SMPS Post-Regulators Typical Application Circuit 20063001 At least 4.7 µF of input and output capacitance is required for stability. © 2006 National Semiconductor Corporation DS200630 www.national.com LP3881 Connection Diagrams 20063002 20063003 TO-220, Top View TO-263, Top View 20063053 PSOP-8, Top View Ordering Information Order Number LP3881ES-1.2 LP3881ESX-1.2 LP3881ET-1.2 LP3881ES-1.5 LP3881ESX-1.5 LP3881ET-1.5 LP3881ES-1.8 LP3881ESX-1.8 LP3881ET-1.8 LP3881EMR-1.2 LP3881EMRX-1.2 LP3881EMR-1.5 LP3881EMRX-1.5 LP3881EMR-1.8 LP3881EMRX-1.8 Package Type TO263-5 TO263-5 TO220-5 TO263-5 TO263-5 TO220-5 TO263-5 TO263-5 TO220-5 PSOP-8 PSOP-8 PSOP-8 PSOP-8 PSOP-8 PSOP-8 Package Drawing TS5B TS5B T05D TS5B TS5B T05D TS5B TS5B T05D MRA08B MRA08B MRA08B MRA08B MRA08B MRA08B Supplied As Rail Tape and Reel Rail Rail Tape and Reel Rail Rail Tape and Reel Rail Rail 2500 Units on Tape and Reel Rail 2500 Units on Tape and Reel Rail 2500 Units on Tape and Reel Block Diagram 20063024 www.national.com 2 LP3881 Absolute Maximum Ratings (Note 1) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Storage Temperature Range Lead Temp. (Soldering, 5 seconds) ESD Rating Human Body Model (Note 3) Machine Model (Note 10) Power Dissipation (Note 2) VIN Supply Voltage (Survival) VBIAS Supply Voltage (Survival) Shutdown Input Voltage (Survival) −65˚C to +150˚C 260˚C 2 kV 200V Internally Limited −0.3V to +6V −0.3V to +7V −0.3V to +7V IOUT (Survival) Output Voltage (Survival) Junction Temperature Internally Limited −0.3V to +6V −40˚C to +150˚C Operating Ratings VIN Supply Voltage Shutdown Input Voltage IOUT Operating Junction Temperature Range VBIAS Supply Voltage (VOUT + VDO) to 5.5V 0 to +6V 0.8A −40˚C to +125˚C 4.5V to 6V Electrical Characteristics Limits in standard typeface are for TJ = 25˚C, and limits in boldface type apply over the full operating temperature range. Unless otherwise specified: VIN = VO(NOM) + 1V, VBIAS = 4.5V, IL = 10 mA, CIN = COUT = 4.7 µF, VS/D = VBIAS. Symbol VO Parameter Output Voltage Tolerance Conditions 10 mA < IL < 0.8A VO(NOM) + 1V ≤ VIN ≤ 5.5V 4.5V ≤ VBIAS ≤ 6V MIN (Note 5) 1.198 1.216 1.186 1.478 1.5 1.455 1.773 1.8 1.746 ∆VO/∆VIN ∆VO/∆IL VDO Output Voltage Line Regulation (Note 7) Output Voltage Load Regulation (Note 8) Dropout Voltage (Note 9) VO(NOM) + 1V ≤ VIN ≤ 5.5V 10 mA < IL < 0.8A IL = 0.8A (TO220 and TO263 only) IL = 0.8A (PSOP only) IQ(VIN) Quiescent Current Drawn from VIN Supply 10 mA < IL < 0.8A V IQ(VBIAS) Quiescent Current Drawn from VBIAS Supply S/D Typical (Note 4) MAX (Note 5) 1.234 1.246 1.522 Units V 1.545 1.827 1.854 0.01 0.04 0.06 75 80 3 0.03 1 0.03 2.5 1.3 0.7 0.7 20 15 1 −1 0.3 120 160 140 190 7 8 1 30 2 3 1 30 %/V %/A mV mA µA mA µA A ≤ 0.3V 10 mA < IL < 0.8A V S/D ≤ 0.3V ISC VSDT Td (OFF) Td (ON) IS/D Short-Circuit Current Output Turn-off Threshold Turn-OFF Delay Turn-ON Delay S/D Input Current VOUT = 0V Output = ON Output = OFF RLOAD X COUT