LM2941QML 1A Low Dropout Adjustable Regulator and the load. Familiar regulator features such as short circuit and thermal overload protection are also provided. General Description The LM2941 positive voltage regulator features the ability to source 1A of output current with a typical dropout voltage of 0.5V and a maximum of 1V over the entire temperature range. Furthermore, a quiescent current reduction circuit has been included which reduces the ground pin current when the differential between the input voltage and the output voltage exceeds approximately 3V. The quiescent current with 1A of output current and an input-output differential of 5V is therefore only 30mA. Higher quiescent currents only exist when the regulator is in the dropout mode (VI - VO 3V). Originally designed for vehicular applications, the LM2941 and all regulated circuitry are protected from reverse battery installations or two-battery jumps. During line transients, such as load dump when the input voltage can momentarily exceed the specified maximum operating voltage, the regulator will automatically shut down to protect both the internal circuits Features Available with radiation guarantee -- ELDRS Free Output voltage adjustable from 5V to 20V Dropout voltage typically 0.5V @ IO = 1A Output current in excess of 1A Trimmed reference voltage Reverse battery protection Internal short circuit current limit Mirror image insertion protection TTL, CMOS compatible ON/OFF switch 100 krad(Si) Ordering Information NS Part Number SMD Part Number NS Package Number Package Description LM2941WG/883 5962-9166701QYA WG16A 16LD Ceramic SOIC LM2941WG-QMLV 5962-9166701VYA WG16A 16LD Ceramic SOIC LM2941WGRLQMLV ELDRS FREE (Note 10) 5962R9166702VYA 100 krad(Si) WG16A 16LD Ceramic SOIC LM2941 MDE ELDRS FREE (Note 10) 5962R9166702V9A 100 krad(Si) (Note 1) Bare Die Note 1: FOR ADDITIONAL DIE INFORMATION, PLEASE VISIT THE HI REL WEB SITE AT: www.national.com/analog/space/level_die Connection Diagrams 16-Lead Ceramic Surface Mount Package 20158532 Top View See NS Package Number WG16A (c) 2009 National Semiconductor Corporation 201585 www.national.com LM2941QML 1A Low Dropout Adjustable Regulator August 25, 2009 LM2941QML Equivalent Schematic Diagram 20158501 www.national.com 2 LM2941QML Absolute Maximum Ratings (Note 2) Input Voltage (Survival Voltage, 100ms) Internal Power Dissipation (Note 3) Maximum Junction Temperature Storage Temperature Range 60V Internally Limited 150C -65C TJ +150C 300C Lead Temperature (Soldering, 10 seconds) Thermal Resistance JA Ceramic SOIC (Still Air) Ceramic SOIC (500LF/Min Air Flow) 122C/W 77C/W JC Ceramic SOIC (Note 4) Package Weight (Typ) Ceramic SOIC ESD susceptibility to be determined. (Note 5) 5C/W 360mg 500V Recommended Operating Conditions Maximum Input Voltage Temperature Range 26V -55C TA 125C Quality Conformance Inspection Mil-Std-883, Method 5005 - Group A Subgroup Description 1 Static tests at 25 2 Static tests at 125 3 Static tests at -55 4 Dynamic tests at 25 5 Dynamic tests at 125 6 Dynamic tests at -55 7 Functional tests at 25 8A Functional tests at 125 8B Functional tests at -55 9 Switching tests at 25 10 Switching tests at 125 11 Switching tests at -55 12 Settling time at 25 13 Settling time at 125 14 Settling time at -55 3 Temp C www.national.com LM2941QML LM2941 Electrical Characteristics DC Parameters The following conditions apply, unless otherwise specified. DC: 5V VO 20V, VIN = VO+5V, CO = 22F Symbol Parameter Conditions VRef Reference Voltage 5mA IO 1A VRLine Line Regulation VO + 2V VIN 26V, IO = 5mA Notes Min Max 1.237 1.313 1.211 1.339 VRLoad Load Regulation 50mA IO 1A, VIN = 10V, VOUT = 5V 50mA IO 1A, VIN = 25V, VOUT = 20V (Note 8) Quiescent Current VIN = VO + 5V, IO = 1A VIN Max = 26V Maximum Operational Input Voltage 2, 3 mV/V 1, 2, 3 10 mV/V 1, 2, 3 10 mV/V 1, 2, 3 15 mA 1 20 mA 2, 3 45 mA 1 2, 3 V 1 1.0 V 2, 3 200 mV 1 300 mV 2, 3 1.6 3.5 A 1 1.3 3.7 A 2, 3 26 VDC 1, 2, 3 V 1, 2, 3 V 1, 2, 3 V 1, 2, 3 (Note 7) Reverse Polarity DC Input Voltage RO = 100, VO -0.6V (Note 6) VTH On ON/OFF Threshold Voltage ON IO 1A (Note 6) VTh Off ON/OFF Threshold Voltage OFF IO 1A (Note 6) ON/OFF Threshold Current V 10 mA Dropout Voltage Short Circuit Current 1 60 IO = 100mA ISC V 0.8 IO = 1A VDO Subgroups (Note 8) VO + 2V VIN 26V, IO = 5mA IQ Unit -15 0.8 2.00 100 A 1 300 A 2, 3 Max Unit Subgroups 60 V 4, 5, 6 -50 V 4, 5, 6 VON/OFF = 2.0V, IO 1A AC Parameters The following conditions apply, unless otherwise specified. AC: 5V VO 20V, VIN = VO+5V, CO = 22F Symbol Parameter Maximum Line Transient Conditions Notes VO Max 1V above nominal VO, RO Min = 100, t 100mS Reverse Polarity Transient Input t 100mS, RO = 100 Voltage RR Ripple Rejection www.national.com O = 1KHz, 1 VRMS, IL = 100mA (Note 9) 0.02 %/V 4 O = 1KHz, 1 VRMS, IL = 100mA (Note 9) 0.04 %/V 5, 6 4 LM2941QML DC Drift Parameters The following conditions apply, unless otherwise specified. DC: 5V VO 20V, VIN = VO+5V, CO = 22F Delta calculations performed on QMLV devices at group B , subgroup 5. Symbol VRef Parameter Reference Voltage Conditions 5mA IO 1A Notes Min Max Unit Subgroups -25 +25 mV 1 Note 2: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics. The guaranteed specifications apply only for the test conditions listed. Some performance characteristics may degrade when the device is not operated under the listed test conditions. Note 3: The maximum power dissipation must be derated at elevated temperatures and is dictated by TJmax (maximum junction temperature), JA (package junction to ambient thermal resistance), and TA (ambient temperature). The maximum allowable power dissipation at any temperature is PDmax = (TJmax - TA)/ JA or the number given in the Absolute Maximum Ratings, whichever is lower. Note 4: The package material for these devices allows much improved heat transfer over our standard ceramic packages. In order to take full advantage of this improved heat transfer, heat sinking must be provided between the package base (directly beneath the die), and either metal traces on, or thermal vias through, the printed circuit board. Without this additional heat sinking, device power dissipation must be calculated using JA, rather than JC, thermal resistance. It must not be assumed that the device leads will provide substantial heat transfer out of the package, since the thermal resistance of the lead frame material is very poor, relative to the material of the package base. The stated JC thermal resistance is for the package material only, and does not account for the additional thermal resistance between the package base and the printed circuit board. The user must determine the value of the additional thermal resistance and must combine this with the stated value for the package, to calculate the total allowed power dissipation for the device. Note 5: Human body model, 1.5 k in series with 100 pF. Note 6: Functional test go-no-go only. Note 7: Condition for VIN Note 8: Limit = mV per volt of VO. Note 9: %/V = % of VIN per Volt of VO. Note 10: These parts are tested on a wafer by wafer basis at high and low dose rates according to MIL-STD-883 Test Method 1019 Conditions A and D with no enhanced low dose rate sensitivity (ELDRS). Pre and post irradiation limits are identical to those listed under AC and DC electrical characteristics. 5 www.national.com LM2941QML Typical Performance Characteristics Dropout Voltage Dropout Voltage vs. Temperature 20158512 20158511 Output Voltage Quiescent Current vs. Temperature 20158513 20158514 Quiescent Current Quiescent Current 20158515 www.national.com 20158516 6 LM2941QML Line Transient Response Load Transient Response 20158518 20158517 Ripple Rejection Output Impedance 20158519 20158520 Low Voltage Behavior Low Voltage Behavior 20158521 20158522 7 www.national.com LM2941QML Output Capacitor ESR Output at Voltage Extremes 20158524 20158523 Output at Voltage Extremes Peak Output Current 20158525 www.national.com 20158526 8 LM2941QML Typical Applications 5V to 20V Adjustable Regulator 20158503 Note: Using 1K for R1 will ensure that the input bias current error of the adjust pin will be negligible. Do not bypass R1 or R2. This will lead to instabilities. * Required if regulator is located far from power supply filter. ** CO must be at least 22F to maintain stability. May be increased without bound to maintain regulation during transients. Locate as close as possible to the regulator. This capacitor must be rated over the same operating temperature range as the regulator and the ESR is critical; see curve. 1A Switch 20158506 *** To assure shutdown, select Resistor R3 to guarantee at least 300A of pull-up current when S1 is open. (Assume 2V at the ON/OFF pin.) 9 www.national.com LM2941QML Revision History Section Released 08/25/09 www.national.com Revision A Section Changes New Release, Corporate format 10 1 MDS data sheet converted into one Corp. data sheet format. Added Radiation products to ordering table. MNLM2941-X Rev 4A1 will be archived. LM2941QML Physical Dimensions inches (millimeters) unless otherwise noted 16LD Ceramic SOIC NS Package Number WG16A 11 www.national.com LM2941QML 1A Low Dropout Adjustable Regulator Notes For more National Semiconductor product information and proven design tools, visit the following Web sites at: Products Design Support Amplifiers www.national.com/amplifiers WEBENCH(R) Tools www.national.com/webench Audio www.national.com/audio App Notes www.national.com/appnotes Clock and Timing www.national.com/timing Reference Designs www.national.com/refdesigns Data Converters www.national.com/adc Samples www.national.com/samples Interface www.national.com/interface Eval Boards www.national.com/evalboards LVDS www.national.com/lvds Packaging www.national.com/packaging Power Management www.national.com/power Green Compliance www.national.com/quality/green Switching Regulators www.national.com/switchers Distributors www.national.com/contacts LDOs www.national.com/ldo Quality and Reliability www.national.com/quality LED Lighting www.national.com/led Feedback/Support www.national.com/feedback Voltage Reference www.national.com/vref Design Made Easy www.national.com/easy www.national.com/powerwise Solutions www.national.com/solutions Mil/Aero www.national.com/milaero PowerWise(R) Solutions Serial Digital Interface (SDI) www.national.com/sdi Temperature Sensors www.national.com/tempsensors SolarMagicTM www.national.com/solarmagic Wireless (PLL/VCO) www.national.com/wireless www.national.com/training PowerWise(R) Design University THE CONTENTS OF THIS DOCUMENT ARE PROVIDED IN CONNECTION WITH NATIONAL SEMICONDUCTOR CORPORATION ("NATIONAL") PRODUCTS. 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