LM2931General DescriptionFeaturesConnection DiagramsFIXED VOLTAGE OUTPUTADJUSTABLE OUTPUT VOLTAGEOrdering InformationTypical ApplicationsLM2931 Adjustable OutputAbsolute Maximum RatingsElectrical Characteristics for Fixed 3.3V VersionElectrical Characteristics for Fixed 5V VersionElectrical Characteristics for Adjustable VersionTypical Performance CharacteristicsSchematic DiagramApplication HintsDefinition of TermsPhysical DimensionsJune 2005LM2931Series Low Dropout RegulatorsGeneral DescriptionThe LM2931 positive voltage regulator features a very lowquiescent current of 1mA or less when supplying 10mA loads.This unique characteristic and the extremely low input-outputdifferential required for proper regulation (0.2V for output cur-rents of 10mA) make the LM2931 the ideal regulator forstandby power systems. Applications include memory stand-by circuits, CMOS and other low power processor powersupplies as well as systems demanding as much as 100mAof output current.Designed originally for automotive applications, the LM2931and all regulated circuitry are protected from reverse batteryinstallations or 2 battery jumps. During line transients, suchas a load dump (60V) when the input voltage to the regulatorcan momentarily exceed the specified maximum operatingvoltage, the regulator will automatically shut down to protectboth internal circuits and the load. The LM2931 cannot beharmed by temporary mirror-image insertion. Familiar regu-lator features such as short circuit and thermal overload pro-tection are also provided.The LM2931 family includes a fixed 5V output (±3.8% toler-ance for A grade) or an adjustable output with ON/OFF pin.Both versions are available in a TO-220 power package,TO-263 surface mount package, and an 8-lead surface mountpackage. The fixed output version is also available in theTO-92 plastic and 6-Bump micro SMD packages.Features■Very low quiescent current■Output current in excess of 100 mA■Input-output differential less than 0.6V■Reverse battery protection■60V load dump protection■−50V reverse transient protection■Short circuit protection■Internal thermal overload protection■Mirror-image insertion protection■Available in TO-220, TO-92, TO-263, SO-8 or 6-Bump mi-cro SMD packages■Available as adjustable with TTL compatible switch■See AN-1112 for micro SMD considerationsConnection DiagramsFIXED VOLTAGE OUTPUTTO-220 3-Lead Power Package525406Front ViewTO-263 Surface-Mount Package525411Top View525412Side View8-Pin Surface Mount525407*NC = Not internally connected. Must be electrically isolated from the rest ofthe circuit for the micro SMD package.Top ViewTO-92 Plastic Package525408Bottom View© 2006 National Semiconductor Corporation 5254 www.national.comLM2931 Series Low Dropout Regulators6-Bump micro SMD525438Top View(Bump Side Down)micro SMD Laser Mark525439ADJUSTABLE OUTPUT VOLTAGETO-220 5-Lead Power Package525409Front ViewTO-2635-Lead Surface-Mount Package525413Top View525414Side View8-Pin Surface Mount525410Top Viewwww.national.com 2LM2931Ordering InformationOutputNumberPackage Part Number Package Marking Transport Media NSC Drawing5V 3-Pin TO-220 LM2931T-5.0 LM2931T-5.0 Rails T03BLM2931AT-5.0 LM2931AT-5.0 Rails3-Pin TO-263 LM2931S-5.0 LM2931S-5.0 Rails TS3BLM2931AS-5.0 LM2931AS-5.0 RailsTO-92 LM2931Z-5.0 LM2931Z-5 1.8k Units per Box Z03ALM2931AZ-5.0 LM2931AZ 1.8k Units per Box8-PinSOICLM2931M-5.0 2931M-5.0 Rails M08ALM2931AM-5.0 2931AM-5.0 Rails * 6-Bumpmicro SMDLM2931IBPX-5.0‐Tape and Reel BPA06HTAAdjustable,3V to 24V5-Pin TO-220 LM2931CT LM2931CT Rails T05A5-Pin TO-263 LM2931CS LM2931CS Rails TS5B8-PinSOICLM2931CM LM2931CM Rails M08A3.3V * 6-Bumpmicro SMDLM2931IBPX-3.3‐Tape and Reel BPA06HTBNote:The micro SMD package marking is a single digitmanufacturing Date Code Only.3 www.national.comLM2931Typical ApplicationsLM2931 Fixed Output525404*Required if regulator is located far from power supply filter.**C2 must be at least 100 μF to maintain stability. May be increased without bound to maintain regulation during transients. Locate as close as possible to theregulator. This capacitor must be rated over the same operating temperature range as the regulator. The equivalent series resistance (ESR) of this capacitor iscritical; see curve.LM2931 Adjustable Output525405Note: Using 27k for R1 will automatically compensate for errors in VOUT due to the input bias current of the ADJ pin (approximately 1 μA).www.national.com 4LM2931Absolute Maximum Ratings (Note 1)If Military/Aerospace specified devices are required,please contact the National Semiconductor Sales Office/Distributors for availability and specifications.Input Voltage Operating Range 26V Overvoltage Protection LM2931A, LM2931C (Adjustable) 60V LM2931 50VInternal Power Dissipation (Notes 2, 4) Internally LimitedOperating Ambient Temperature Range−40°C to +85°CMaximum Junction Temperature 125°CStorage Temperature Range −65°C to +150°CLead Temp. (Soldering, 10 seconds) 230°CESD Tolerance (Note 5) 2000VElectrical Characteristics for Fixed 3.3V VersionVIN = 14V, IO = 10mA, TJ = 25°C, C2 = 100μF (unless otherwise specified) (Note 2)Parameter Conditions LM2931-3.3 UnitsTyp Limit(Note 3)Output Voltage 3.3 3.4653.135VMAXVMIN4V ≤ VIN ≤ 26V, IO = 100 mA−40°C ≤ TJ ≤ 125°C 3.6302.970VMAXVMINLine Regulation4V ≤ VIN ≤ 26V4 33 mVMAXLoad Regulation5mA ≤ IO ≤ 100mA10 50 mVMAXOutput Impedance 100mADC and 10mArms,100Hz - 10kHz200 mΩQuiescent CurrentIO ≤ 10mA, 4V ≤ VIN ≤ 26V0.4 1.0 mAMAX −40°C ≤ TJ ≤ 125°C IO = 100mA, VIN = 14V, TJ = 25°C 15 mAOutput Noise Voltage10Hz -100kHz, COUT = 100μF330 μVrmsLong Term Stability 13 mV/1000 hrRipple Rejection fO = 120Hz 80 dBDropout Voltage IO = 10mAIO = 100mA0.050.300.20.6VMAXMaximum Operational InputVoltage 33 26 VMINMaximum Line TransientRL = 500Ω, VO ≤ 5.5V,T = 1ms, τ ≤ 100ms70 50 VMINReverse Polarity Input Voltage, DCVO ≥ −0.3V, RL = 500Ω−30 −15 VMINReverse Polarity Input Voltage,TransientT = 1ms, τ ≤ 100ms, RL = 500Ω−80 −50 VMIN5 www.national.comLM2931Electrical Characteristics for Fixed 5V VersionVIN = 14V, IO = 10mA, TJ = 25°C, C2 = 100 μF (unless otherwise specified) (Note 2)Parameter Conditions LM2931A-5.0 LM2931-5.0 UnitsTypLimit(Note 3)TypLimit(Note 3)Output Voltage 5 5.194.815 5.254.75VMAXVMIN6.0V ≤ VIN ≤ 26V, IO = 100mA−40°C ≤ TJ ≤ 125°C 5.254.75 5.54.5VMAXVMINLine Regulation9V ≤ VIN ≤ 16V6V ≤ VIN ≤