LSP2155 1A Ultra Low Dropout CMOS Regulator Features General Description Low-Dropout Regulator Supports Input The LSP2155 is a 1A CMOS LDO regulator that features a low quiescent current, ultra low input, output and dropout voltages, as well as over temperature shutdown. It is available in SOT223-3L, TO252-3L, SOP-8L package. The fixed output voltage of the LSP2155 is set at the factory and trimmed to 2%. The LSP2155 is stable with a ceramic output capacitor of 2.2uF or higher. This family of regulators can provide either a stand-alone power supply solution or act as a post regulator for switch mode power supplies. They are particularly well suited for applications requiring low input and output voltage. Voltages Down to 1.45V Output Voltage Available in fixed 1.2V, 1.8V, 2.5V, 3.3V and ADJ version Stable with 2.2uF or higher Ceramic Output Capacitor Low Dropout Voltage: 250mV at 1A Low Quiescent Current Over Temperature Protection Over Current Protection Short Circuit Protection PackageSOT223-3L, TO252-3L, SOP-8L Applications 1.2V Core Voltage for DSPs Telecom Equipment SATA Power Supply Portable Electronics LCD TV/Monitor Typical Application Circuit VIN OUT VIN VIN 4.7uF GND VOUT LSP2155 LSP2155 C1 OUT VIN VOUT C2 2.2uF C1 4.7uF GND R1 Cff 100pF ADJ C2 R2 2.2uF Please be aware that an Important Notice concerning availability, disclaimers, and use in critical applications of LSC products is at the end of this document. LSP2155 1A Ultra Low Dropout CMOS Regulator Ordering Information L S P 2 15 5 X X X Package : B E : S O T 2 2 3 -3 L B D : T O 2 5 2 -3 L E : S O T 2 2 3 -3 L D : T O 2 5 2 -3 L S : S O P -8 L O u tp u t V o lta g e : B la n k : A D J 1 2 : 1 .2 V 1 8 : 1 .8 V 2 5 : 2 .5 V 3 3 : 3 .3 V Device Package Code Package LSP2155EXXA LSP2155BEXXA LSP2155DXXA LSP2155BDXXA LSP2155SA E BE D BD S SOT223-3L SOT223-3L TO252-3L TO252-3L SOP-8L P a c k in g : A : Tape & R eel Tape & Reel Part Number Quantity Suffix 2500 A 2500 A 2500 A 2500 A 2500 A Pin Assignments TO252-3L (Top View) SOT223-3L (Top View) SOP-8L (Top View) 3 3 2 2 1 Tab is Pin 2 1 1 8 2 7 3 6 4 5 Tab is Pin 2 Pin Descriptions SOT223-3L TO252-3L 1 2,TAB 3 Pin Number SOT223-3L (B) TO252-3L (B) 3 1 2,TAB SOP-8L 2 1,4, 8 7 6 3,5 Name Description VIN GND VOUT ADJ NC Voltage Input Ground Pin Voltage Output Feedback Pin No Connected LSP2155 1A Ultra Low Dropout CMOS Regulator Block Diagram Fixed version IN OUT ADJ version IN OverCurrent Shutdown OverCurrent Shutdown Thermal Shutdown Thermal Shutdown R1 OUT R1 AMP outside for ADJ AMP ADJ R2 R2 GND outside for ADJ GND Absolute Maximum Ratings Parameter Input Supply Voltage Maximum Output Current Power Dissipation SOT223-3L TO252-3L SOP-8L Storage Temperature Range Maximum Junction Temperature Value Unit -0.3 to 4 PD/(VIN-VOUT) V A Internal Limitation mW o -65 to +150 150 C C o Recommended Operating Conditions Parameter Input Supply Voltage Operating Junction Temperature Output Current Min 1.45V (Notes1) -20 Max Unit 3.8 +125 1 V C A Note1 : The minimum input voltage of the LSP2155 is determined by output voltage and dropout voltage. The minimum input voltage is defined as : VIN = VOUT + VDROP LSP2155 1A Ultra Low Dropout CMOS Regulator Electrical Characteristics (VIN = VOUT+0.5V; CIN = 4.7uF, COUT = 2.2 uF, TA = 25 unless otherwise specified ) Parameter Symbol Test Conditions VO IO= 100mA VO = 0.9V,IO=1A VO =1.2V,IO=1A VO =1.8V,IO=1A VO =2.5V,IO=1A VO =3.3V,IO=1A Output Voltage Accuracy Dropout Voltage VDROP Current Limit Short Circuit Current Quiescent Current Line Regulation Load Regulation Error ADJ Input Bias Current ADJ Reference Voltage Over Temperature Protection Over Temperature Hysteresis Power Supply Ripple Rejection ILimit ISC IQ LNR LDR IADJ VREF OTP OTH PSRR Min Typ Max Unit -2 +2 550 250 160 140 130 2 0.8 250 VO < 0.3V VIN = 1.7V, IO= 0mA VIN = 1.45 V to 3.8V, IO = 10mA IO =10mA to 1A VIN = 3.8V , VOUT = 0.9V mV 1 2 0.882 1 0.9 150 45 60 % 0.918 A A uA %/V %/V % V dB Application Description The LSP2155 family of low-dropout regulators have several features that allow them to apply to a wide range of applications. The family operates with very low input voltage (1.45V) and low dropout voltage (see Electrical Characteristics Table), making it an efficient stand-alone power supply or post regulator for battery or switch mode power supplies. The 1A output current make the LSP2155 family suitable for powering many microprocessors and FPGA supplies. The LSP2155 family also has low output noise (typically 40uVRMS with 2.2uF output capacitor), making it ideal for use in telecom equipment. External Capacitor Requirement A 2.2uF or larger ceramic input bypass capacitor, connected between VIN and GND and located close to the LSP2155, is required for stability. A 1.0uF minimum value capacitor from VOUT to GND is also required. To improve transient response, noise rejection, and ripple rejection, an additional 10uF or larger, low ESR capacitor is recommended at the output. A higher-value, low ESR output capacitor may be necessary if large, fast-rise-time load transients are anticipated and the device is located several inches from the power source, especially if the minimum input voltage of 1.45 V is used. Regulator Protection The LSP2155 features internal current limiting, thermal protection and short circuit protection. During normal operation, the LSP2155 limits output current to about 2A. When current limiting LSP2155 1A Ultra Low Dropout CMOS Regulator engages, the output voltage scales back linearly until the over current condition ends. While current limiting is designed to prevent gross device failure, care should be taken not to exceed the power dissipation ratings of the package. If the temperature of the device exceeds 160C, thermalprotection circuitry will shut down. Once the device has cooled down to approximately 45C below the high temp trip point, regulator operation resumes. The short circuit current of the LSP2155 is about 1A when its output pin is shorted to ground. Thermal Information The amount of heat that an LDO linear regulator generates is: D = (VIN-VOUT) x IOUT. All integrated circuits have a maximum allowable junction temperature (TJ max) above which normal operation is not assured. A system designer must design the operating environment so that the operating junction temperature (TJ) does not exceed the maximum junction temperature (TJ max). The two main environmental variables that a designer can use to improve thermal performance are air flow and external heat-sink. The purpose of this information is to aid the designer in determining the proper operating environment for a linear regulator that is operating at a specific power level. In general, the maximum expected power (PD(max)) consumed by a linear regulator is computed as: PD(MAX) = (VIN(avg)- VOUT(avg)) x IOUT (avg) x IQ) Where VIN (avg) is the average input voltage. VOUT (avg) is the average output voltage. IOUT (avg) is the average output current. IQ is the quiescent current. For most LDO regulators, the quiescent current is insignificant compared to the average output current; therefore, the term VIN (avg) x IQ can be neglected. The operating junction temperature is computed by adding the ambient temperature (TA) and the increase in temperature due to the regulator's power dissipation. The temperature rise is computed by multiplying the maximum expected power dissipation by the sum of the thermal resistances between the junction and the case (RJC), the case to heat-sink (RCS), and the heat-sink to ambient (RSA). Thermal resistances are measures of how effectively an object dissipates heat. Typically, the larger the device, the more surface area available for power dissipation, so that the object's thermal resistance will be lower. ADJ VERSION The adjustable version uses external feedback resistors to generate an output voltage anywhere from 1.45V to 5.0V. VADJ is trimmed to 0.9V and VOUT is given by the equation: VOUT = VADJ ( 1 + R1 / R2) LSP2155 1A Ultra Low Dropout CMOS Regulator VOUT R1 ADJ R2 Feedback resistors R1 and R2 should be high enough to keep quiescent current low, but increasing R1 + R2 will reduce stability. In general, R1=100K will produce adequate stability, given reasonable layout precautions. To improve stability characteristics, keep parasitic on the ADJ pin to a minimum, and lower R1 and R2 values. LSP2155 1A Ultra Low Dropout CMOS Regulator Typical Performance Characteristics Line Regulation (IOUT=10mA) 1.22 1.81 VOUT (V) 1.21 VOUT (V) Line Regulation (IOUT=10mA) 1.82 1.20 1.19 1.80 1.79 1.18 1.78 1.4 1.8 2.2 2.6 3.0 3.4 3.8 2.3 2.6 2.9 VIN (V) 1.23 3.36 1.22 3.34 1.21 3.32 VOUT (V) VOUT (V) 3.5 3.8 VIN (V) Load Regulation (V OUT=1.2V) 1.20 Load Regulation (VOUT=3.3V) 3.30 3.28 1.19 1.18 3.26 0.0 0.2 0.4 0.6 0.8 1.0 0.0 0.2 0.4 IOUT (A) 0.6 0.8 1.0 0.8 1.0 IOUT (A) Quiescent Current vs. VIN 200 Ground Current vs. IOUT 600 175 500 150 400 IGND (uA) IQ (uA) 3.2 125 100 75 VO=1.2V VO=3.3V 300 200 100 50 0 1.4 1.8 2.2 2.6 VIN (V) 3.0 3.4 3.8 0.0 0.2 0.4 IOUT (A) 0.6 LSP2155 1A Ultra Low Dropout CMOS Regulator Current Limit vs. VIN 2.4 Dropout Voltage (mV) Current (A) 2.0 1.6 1.2 0.8 0.4 1.4 1.8 2.2 2.6 VIN (V) 3.0 Dropout Voltage vs. IOUT 300 3.4 VOUT=1.2V VOUT=1.8V VOUT=3.3V 250 200 150 100 3.8 50 0 0.0 0.2 0.4 0.6 IOUT (A) Load Transient (VIN=1.7V, Load=0.1A to 1A) VOUT (AC) 20mV/div. IOUT 0.8 1.0 LSP2155 1A Ultra Low Dropout CMOS Regulator Marking Information SOT223-3L B type LSP2155B-VV YYWWXX Part Number : LSP2155B-ADJ : Blank LSP2155B-12 : 1.2V LSP2155B-18 : 1.8V LSP2155B-25 : 2.5V LSP2155B-33 : 3.3V Internal Code Date Code : YYYear(09=2009,10=2010,11=2011,12=2012...) WWNth week (01~53) TO252-3L B type LSC LSP2155B-VV YYWWXX Logo Part Number : LSP2155B-ADJ : Blank LSP2155B-12 : 1.2V LSP2155B-18 : 1.8V LSP2155B-25 : 2.5V LSP2155B-33 : 3.3V Internal Code Date Code : YYYear(09=2009,10=2010,11=2011,12=2012...) WWNth week (01~53) LSP2155 1A Ultra Low Dropout CMOS Regulator SOT223-3L LSP2155-VV YYWWXX Part Number : LSP2155-ADJ : Blank LSP2155-12 : 1.2V LSP2155-18 : 1.8V LSP2155-25 : 2.5V LSP2155-33 : 3.3V Internal Code Date Code : YYYear(09=2009,10=2010,11=2011,12=2012...) WWNth week (01~53) TO252-3L LSC LSP2155-VV YYWWXX Logo Part Number : LSP2155-ADJ : Blank LSP2155-12 : 1.2V LSP2155-18 : 1.8V LSP2155-25 : 2.5V LSP2155-33 : 3.3V Internal Code Date Code : YYYear(09=2009,10=2010,11=2011,12=2012...) WWNth week (01~53) SOP-8L LSC LSP2155-VV YYWWXX Logo Part Number : LSP2155-ADJ : Blank LSP2155-12 : 1.2V LSP2155-18 : 1.8V LSP2155-25 : 2.5V LSP2155-33 : 3.3V Internal Code Date Code YYYear(09=2009,10=2010,11=2011,12=2012...) WWNth week (01~53) LSP2155 1A Ultra Low Dropout CMOS Regulator Package Information (All Dimensions in min) (1) TO252-3L 5.6 E H 2.25 L SEATING PLANE 7.2 D 11.0 C A1 5.6 L2 C1 2.0 L1 SEE NOTE2 1.2 b e Land Pattern Recommendation (Unit : mm) e1 Notes: 1.JEDEC Outline:TO-252 AB Mils suggested for positive contact at mounting Symbol A A1 b b2 C C1 D E e e1 H L L1 L2 Dimensions In Millimeters Min Nom Max 2.18 1.02 5.20 0.46 0.46 5.33 6.35 9.00 0.51 0.64 1.52 2.39 1.27 Dimensions In Inches Min Nom Max 2.29 1.15 0.61TYP. 5.35 0.52 0.52 5.57 6.58 2.25BSC. 4.50BSC. 9.70 0.086 0.040 5.50 0.58 0.58 5.80 6.80 0.205 0.018 0.018 0.210 0.250 10.40 0.83 1.78 1.02 2.03 0.354 0.020 0.025 0.060 0.090 0.045 0.024TYP. 0.211 0.020 0.020 0.219 0.259 0.089BSC. 0.177BSC. 0.382 0.094 0.050 0.033 0.070 0.040 0.080 0.217 0.023 0.023 0.228 0.268 0.409 A b2 LSP2155 1A Ultra Low Dropout CMOS Regulator (2) SOT223-3L 3.3 D 1.6 E H 6.4 1.6 B1 K 1.2 e 2.3 e1 Land Pattern Recommendation (Unit :mm) L Seating Plane B C a A A1 Symbol A A1 B B1 c D E e e1 H L K Dimensions In Millimeters Min Nom Max 1.50 0.02 0.60 2.90 0.28 6.30 3.30 6.70 0.91 1.50 0 1.65 0.05 0.70 0.30 6.50 3.50 2.3Basic 4.6Basic 7.00 1.00 1.75 5 13 Min 1.80 0.08 0.80 3.15(Ref.) 0.32 6.70 3.70 0.059 0.001 0.024 0.114 0.011 0.248 0.130 7.30 1.10 2.00 10 0.264 0.036 0.059 0 Dimensions In Inches Nom Max 0.065 0.002 0.028 0.012 0.256 0.138 0.091Basic 0.181Basic 0.276 0.039 0.069 5 13 0.071 0.003 0.031 0.124(Ref.) 0.013 0.264 0.146 0.287 0.043 0.079 10 LSP2155 1A Ultra Low Dropout CMOS Regulator (3) SOP-8L 0.25 C E E1 D L L1 e B B b D c1 A A2 A3 WITH PLATING SECTION B-B A1 BASE METAL Symbol A A1 A2 A3 b b1 c c1 D E E1 e L L1 Dimensions In Millimeters Min Nom Max 0.10 1.30 0.60 0.39 0.38 0.21 0.19 4.70 5.80 3.70 0.50 0 1.40 0.65 0.41 0.20 4.90 6.00 3.90 1.27BSC 1.05BSC - 1.75 0.25 1.50 0.70 0.48 0.43 0.26 0.21 5.10 6.20 4.10 0.80 8 c b b1 LSP2155 1A Ultra Low Dropout CMOS Regulator Important Notice and Disclaimer LSC reserves the right to make changes to this document and its products and specifications at any time without notice. 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