LP2986 Micropower, 200 mA Ultra Low-Dropout Fixed or Adjustable Voltage Regulator General Description Features The LP2986 is a 200 mA precision LDO voltage regulator which offers the designer a higher performance version of the industry standard LP2951. n n n n n n n n n n Using an optimized VIP™ (Vertically Integrated PNP) process, the LP2986 delivers superior performance: Dropout Voltage: Typically 180 mV @ 200 mA load, and 1 mV @ 1 mA load. Ground Pin Current: Typically 1 mA @ 200 mA load, and 200 µA @ 10 mA load. Sleep Mode: The LP2986 draws less than 1 µA quiescent current when shutdown pin is pulled low. Error Flag: The built-in error flag goes low when the output drops approximately 5% below nominal. Precision Output: The standard product versions available can be pin-strapped (using the internal resistive divider) to provide output voltages of 5.0V, 3.3V, or 3.0V with guaranteed accuracy of 0.5% (“A” grade) and 1% (standard grade) at room temperature. Ultra low dropout voltage Guaranteed 200 mA output current SO-8 and mini-SO8 surface mount packages < 1 µA quiescent current when shutdown Low ground pin current at all loads 0.5% output voltage accuracy (“A” grade) High peak current capability (400 mA typical) Wide supply voltage range (16V max) Overtemperature/overcurrent protection −40˚C to +125˚C junction temperature range Applications n Cellular Phone n Palmtop/Laptop Computer n Camcorder, Personal Stereo, Camera Block Diagram DS012935-1 VIP™ is a trademark of National Semiconductor Corporation. © 1999 National Semiconductor Corporation DS012935 www.national.com LP2986 Micropower, 200 mA Ultra Low-Dropout Fixed or Adjustable Voltage Regulator March 1999 Connection Diagram and Ordering Information Surface Mount Packages: Mini SO-8 Package Type MM: See NS Package Drawing Number MUA08A SO-8 Package Type M: See NS Package Drawing Number M08A DS012935-2 Top View For ordering information, refer to Table 1 of this document. Basic Application Circuits Application Using Internal Resistive Divider DS012935-3 www.national.com 2 Basic Application Circuits (Continued) Application Using External Divider DS012935-4 Ordering Information TABLE 1. Package Marking and Ordering Information Output Voltage Grade Order Information Package Marking Supplied as: 5 A LP2986AIMMX-5.0 L41A 3.5k Units on Tape and Reel 5 A LP2986AIMM-5.0 L41A 250 Units on Tape and Reel 5 STD LP2986IMMX-5.0 L41B 3.5k Units on Tape and Reel 5 STD LP2986IMM-5.0 L41B 250 Units on Tape and Reel 3.3 A LP2986AIMMX-3.3 L40A 3.5k Units on Tape and Reel 3.3 A LP2986AIMM-3.3 L40A 250 Units on Tape and Reel 3.3 STD LP2986IMMX-3.3 L40B 3.5k Units on Tape and Reel 3.3 STD LP2986IMM-3.3 L40B 250 Units on Tape and Reel 3.0 A LP2986AIMMX-3.0 L39A 3.5k Units on Tape and Reel 3.0 A LP2986AIMM-3.0 L39A 250 Units on Tape and Reel 3.0 STD LP2986IMMX-3.0 L39B 3.5k Units on Tape and Reel 3.0 STD LP2986IMM-3.0 L39B 250 Units on Tape and Reel 5 A LP2986AIMX-5.0 2986AIM5.0 2.5k Units on Tape and Reel 5 A LP2986AIM-5.0 2986AIM5.0 Shipped in Anti-Static Rails 5 STD LP2986IMX-5.0 2986IM5.0 2.5k Units on Tape and Reel 5 STD LP2986IM-5.0 2986IM5.0 Shipped in Anti-Static Rails 3.3 A LP2986AIMX-3.3 2986AIM3.3 2.5k Units on Tape and Reel 3.3 A LP2986AIM-3.3 2986AIM3.3 Shipped in Anti-Static Rails 3.3 STD LP2986IMX-3.3 2986IM3.3 2.5k Units on Tape and Reel 3.3 STD LP2986IM-3.3 2986IM3.3 Shipped in Anti-Static Rails 3.0 A LP2986AIMX-3.0 2986AIM3.0 2.5k Units on Tape and Reel 3.0 A LP2986AIM-3.0 2986AIM3.0 Shipped in Anti-Static Rails 3.0 STD LP2986IMX-3.0 2986IM3.0 2.5k Units on Tape and Reel 3.0 STD LP2986IM-3.0 2986IM3.0 Shipped in Anti-Static Rails 3 www.national.com Absolute Maximum Ratings (Note 1) Input Supply Voltage (Operating) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. −0.3V to +16V Feedback Pin −0.3V to +5V Storage Temperature Range −65˚C to +150˚C Operating Junction Temperature Range Output Voltage (Survival) (Note 4) −40˚C to +125˚C IOUT (Survival) Lead Temperature (Soldering, 5 seconds) −0.3V to +16V Short Circuit Protected Input-Output Voltage (Survival) (Note 5) 260˚C ESD Rating (Note 2) 2.1V to +16V Shutdown Pin −0.3V to +16V 2 kV Power Dissipation (Note 3) Internally Limited Input Supply Voltage (Survival) −0.3V to +16V Electrical Characteristics Limits in standard typeface are for T J = 25˚C, and limits in boldface type apply over the full operating temperature range. Unless otherwise specified: VIN = VO(NOM) + 1V, IL = 1 mA, COUT = 4.7 µF, CIN = 2.2 µF, VS/D = 2V. Symbol VO Parameter Output Voltage (5.0V Versions) Output Voltage (3.3V Versions) Output Voltage (3.0V Versions) VIN–VO Conditions Typical 5.0 0.1 mA < IL < 200 mA 3.3 0.1 mA < IL < 200 mA Output Voltage Line Regulation VO(NOM) + 1V ≤ VIN ≤ 16V Dropout Voltage (Note 7) IL = 100 µA 3.0 LM2986I-X.X (Note 6) Min Min 5.025 4.950 5.050 5.040 4.920 5.080 4.910 5.090 4.860 5.140 3.283 3.317 3.267 3.333 3.274 3.326 3.247 3.353 3.241 3.359 3.208 3.392 2.985 3.015 2.970 3.030 2.976 3.024 2.952 3.048 3.054 2.916 3.084 2.946 0.007 180 100 IL = 75 mA 500 IL = 200 mA 1 Units Max 4.975 90 IL = 100 µA Max 4.960 1 IL = 200 mA Ground Pin Current 3.3 3.0 0.1 mA < IL < 200 mA IL = 75 mA IGND 5.0 LM2986AI-X.X (Note 6) 0.014 0.014 0.032 0.032 2.0 2.0 3.5 3.5 120 120 170 170 230 230 350 350 120 120 150 150 800 800 1400 1400 2.1 2.1 3.7 3.7 V %/V mV µA mA VS/D < 0.3V 0.05 IO(PK) Peak Output Current VOUT ≥ VO(NOM) − 5% 400 IO(MAX) Short Circuit Current RL = 0 (Steady State) (Note 11) 400 en Output Noise Voltage (RMS) BW = 300 Hz to 50 kHz, COUT = 10 µF 160 µV(RMS) Ripple Rejection f = 1 kHz, COUT = 10 µF 65 dB www.national.com 4 1.5 250 1.5 µA 250 mA Electrical Characteristics (Continued) Limits in standard typeface are for T J = 25˚C, and limits in boldface type apply over the full operating temperature range. Unless otherwise specified: VIN = VO(NOM) + 1V, IL = 1 mA, COUT = 4.7 µF, CIN = 2.2 µF, VS/D = 2V. Symbol Parameter Output Voltage Temperature Coefficient Conditions Typical (Note 9) LM2986AI-X.X (Note 6) LM2986I-X.X (Note 6) Min Min Max Units Max 20 ppm/˚C FEEDBACK PIN VFB Feedback Pin Voltage 1.23 (Note 10) IFB FB Pin Voltage Temperature Coefficient (Note 9) Feedback Pin Bias Current IL = 200 mA FB Pin Bias Current Temperature Coefficient (Note 9) 1.23 1.21 1.25 1.20 1.26 1.20 1.26 1.19 1.27 1.19 1.28 1.18 1.29 20 V ppm/˚C 150 330 330 760 760 0.1 nA nA/˚C SHUTDOWN INPUT VS/D IS/D S/D Input Voltage (Note 8) S/D Input Current VH = O/P ON 1.4 VL = O/P OFF 0.55 1.6 0.18 1.6 0.18 VS/D = 0 0 −1 −1 VS/D = 5V 5 15 15 1 1 2 2 220 220 350 350 V µA ERROR COMPARATOR IOH VOL Output “HIGH” Leakage Output “LOW” Voltage VOH = 16V 0.01 VIN = VO(NOM) − 0.5V, IO(COMP) = 300 µA 150 VTHR (MAX) Upper Threshold Voltage −4.6 VTHR (MIN) Lower Threshold Voltage −6.6 HYST Hysteresis 2.0 µA −5.5 −3.5 −5.5 −3.5 −7.7 −2.5 −7.7 −2.5 −8.9 −4.9 −8.9 −4.9 −13.0 −3.3 −13.0 −3.3 mV %VOUT Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the component may occur. Electrical specifications do not apply when operating the device outside of its rated operating conditions. Note 2: The ESD rating of the Feedback pin is 500V and the Tap pin is 1.5 kV. Note 3: The maximum allowable power dissipation is a function of the maximum junction temperature, TJ(MAX), the junction-to-ambient thermal resistance, θJ−A, and the ambient temperature, TA. The maximum allowable power dissipation at any ambient temperature is calculated using: The value of θJ−A for the SO-8 (M) package is 160˚C/W, and the mini SO-8 (MM) package is 200˚C/W. Exceeding the maximum allowable power dissipation will cause excessive die temperature, and the regulator will go into thermal shutdown. Note 4: If used in a dual-supply system where the regulator load is returned to a negative supply, the LM2986 output must be diode-clamped to ground. Note 5: The output PNP structure contains a diode between the V IN and VOUT terminals that is normally reverse-biased. Forcing the output above the input will turn on this diode and may induce a latch-up mode which can damage the part (see Application Hints). Note 6: Limits are 100% production tested at 25˚C. Limits over the operating temperature range are guaranteed through correlation using Statistical Quality Control (SQC) methods. The limits are used to calculate National’s Average Outgoing Quality Level (AOQL). Note 7: Dropout voltage is defined as the input to output differential at which the output voltage drops 100 mV below the value measured with a 1V differential. Note 8: To prevent mis-operation, the Shutdown input must be driven by a signal that swings above VH and below VL with a slew rate not less than 40 mV/µs (see Application Hints). Note 9: Temperature coefficient is defined as the maximum (worst-case) change divided by the total temperature range. Note 10: VFB ≤ VOUT ≤ (VIN − 1), 2.5V ≤ VIN ≤ 16V, 100 µA ≤ IL ≤ 200 mA, TJ ≤ 125˚C. Note 11: See Typical Performance Characteristics curves. 5 www.national.com Typical Performance Characteristics Unless otherwise specified: TA = 25˚C, COUT = 4.7 µF, CIN = 2.2 µF, S/D is tied to VIN, VIN = VO(NOM) + 1V, IL = 1 mA. VOUT vs Temperature Dropout Voltage vs Temperature DS012935-8 DS012935-9 Dropout Characteristics Dropout Voltage vs Load Current DS012935-10 Ground Pin Current vs Temperature and Load DS012935-13 Ground Pin Current vs Load Current DS012935-12 www.national.com DS012935-11 6 Typical Performance Characteristics Unless otherwise specified: TA = 25˚C, COUT = 4.7 µF, CIN = 2.2 µF, S/D is tied to VIN, VIN = VO(NOM) + 1V, IL = 1 mA. (Continued) Input Current vs VIN Input Current vs VIN DS012935-15 DS012935-14 Load Transient Response Load Transient Response DS012935-17 DS012935-16 Line Transient Response Line Transient Response DS012935-20 DS012935-18 7 www.national.com Typical Performance Characteristics Unless otherwise specified: TA = 25˚C, COUT = 4.7 µF, CIN = 2.2 µF, S/D is tied to VIN, VIN = VO(NOM) + 1V, IL = 1 mA. (Continued) Turn-Off Waveform Turn-On Waveform DS012935-23 DS012935-21 Short Circuit Current Short Circuit Current DS012935-24 Short Circuit Current vs Output Voltage DS012935-25 Instantaneous Short Circuit Current vs Temperature DS012935-27 DS012935-26 www.national.com 8 Typical Performance Characteristics Unless otherwise specified: TA = 25˚C, COUT = 4.7 µF, CIN = 2.2 µF, S/D is tied to VIN, VIN = VO(NOM) + 1V, IL = 1 mA. (Continued) Feedback Bias Current vs Load DC Load Regulation DS012935-29 DS012935-28 Shutdown Pin Current vs Shutdown Pin Voltage Feedback Bias Current vs Temperature DS012935-31 DS012935-30 Input to Output Leakage vs Temperature Shutdown Voltage vs Temperature DS012935-37 DS012935-32 9 www.national.com Typical Performance Characteristics Unless otherwise specified: TA = 25˚C, COUT = 4.7 µF, CIN = 2.2 µF, S/D is tied to VIN, VIN = VO(NOM) + 1V, IL = 1 mA. (Continued) Output Impedance vs Frequency Output Noise Density DS012935-35 DS012935-34 Ripple Rejection Output Impedance vs Frequency DS012935-36 www.national.com DS012935-33 10 when selecting an output capacitor so that the minimum required amount of output capacitance is provided over the full operating temperature range. A good Tantalum capacitor will show very little variation with temperature, but a ceramic may not be as good (see next section). Application Hints EXTERNAL CAPACITORS Like any low-dropout regulator, external capacitors are required to assure stability. These capacitors must be correctly selected for proper performance. INPUT CAPACITOR: An input capacitor (≥ 2.2 µF) is required between the LP2986 input and ground (amount of capacitance may be increased without limit). CAPACITOR CHARACTERISTICS TANTALUM: The best choice for size, cost, and performance are solid tantalum capacitors. Available from many sources, their typical ESR is very close to the ideal value required on the output of many LDO regulators. Tantalums also have good temperature stability: a 4.7 µF was tested and showed only a 10% decline in capacitance as the temperature was decreased from +125˚C to −40˚C. The ESR increased only about 2:1 over the same range of temperature. However, it should be noted that the increasing ESR at lower temperatures present in all tantalums can cause oscillations when marginal quality capacitors are used (where the ESR of the capacitor is near the upper limit of the stability range at room temperature). This capacitor must be located a distance of not more than 0.5” from the input pin and returned to a clean analog ground. Any good quality ceramic or tantalum may be used for this capacitor. OUTPUT CAPACITOR: The output capacitor must meet the requirement for minimum amount of capacitance and also have an appropriate E.S.R. (equivalent series resistance) value. Curves are provided which show the allowable ESR range as a function of load current for various output voltages and capacitor values (see ESR curves below). CERAMIC: For a given amount of a capacitance, ceramics are usually larger and more costly than tantalums. Be warned that the ESR of a ceramic capacitor can be low enough to cause instability: a 2.2 µF ceramic was measured and found to have an ESR of about 15 mΩ. ESR Curves For 5V Output If a ceramic capacitor is to be used on the LP2986 output, a 1Ω resistor should be placed in series with the capacitor to provide a minimum ESR for the regulator. Another disadvantage of ceramic capacitors is that their capacitance varies a lot with temperature: Large ceramic capacitors are typically manufactured with the Z5U temperature characteristic, which results in the capacitance dropping by a 50% as the temperature goes from 25˚C to 80˚C. This means you have to buy a capacitor with twice the minimum COUT to assure stable operation up to 80˚C. ALUMINUM: The large physical size of aluminum electrolytics makes them unattractive for use with the LP2986. Their ESR characteristics are also not well suited to the requirements of LDO regulators. The ESR of an aluminum electrolytic is higher than a tantalum, and it also varies greatly with temperature. A typical aluminum electrolytic can exhibit an ESR increase of 50X when going from 20˚C to −40˚C. Also, some aluminum electrolytics can not be used below −25˚C because the electrolyte will freeze. DS012935-6 ESR Curves For 2.5V Output USING AN EXTERNAL RESISTIVE DIVIDER The LP2986 output voltage can be programmed using an external resistive divider (see Basic Application Circuits). The resistor connected between the Feedback pin and ground should be 51.1k. The value for the other resistor (R1) connected between the Feedback pin and the regulated output is found using the formula: VOUT = 1.23 x (1 + R1/51.1k) DS012935-7 IMPORTANT: The output capacitor must maintain its ESR in the stable region over the full operating temperature range of the application to assure stability. The minimum required amount of output capacitance is 4.7 µF. Output capacitor size can be increased without limit. It is important to remember that capacitor tolerance and variation with temperature must be taken into consideration It should be noted that the 25 µA of current flowing through the external divider is approximately equal to the current saved by not connecting the internal divider, which means the quiescent current is not increased by using external resistors. 11 www.national.com Application Hints It is also important that the turn-on (and turn-off) voltage signals applied to the Shutdown input have a slew rate which is not less than 40 mV/µs. (Continued) A lead compensation capacitor (CF) must also be used to place a zero in the loop response at about 50 kHz. The value for C F can be found using: CAUTION: the regulator output state can not be guaranteed if a slow-moving AC (or DC) signal is applied that is in the range between VH and VL. CF = 1/(2π x R1 x 50k) A good quality capacitor must be used for CF to ensure that the value is accurate and does not change significantly over temperature. Mica or ceramic capacitors can be used, assuming a tolerance of ± 20% or better is selected. If a ceramic is used, select one with a temperature coefficient of NPO, COG, Y5P, or X7R. Capacitor types Z5U, Y5V, and Z4V can not be used because their value varies more that 50% over the −25˚C to +85˚C temperature range. REVERSE INPUT-OUTPUT VOLTAGE The PNP power transistor used as the pass element in the LP2986 has an inherent diode connected between the regulator output and input. During normal operation (where the input voltage is higher than the output) this diode is reverse-biased. However, if the output is pulled above the input, this diode will turn ON and current will flow into the regulator output. SHUTDOWN INPUT OPERATION In such cases, a parasitic SCR can latch which will allow a high current to flow into VIN (and out the ground pin), which can damage the part. The LP2986 is shut off by driving the Shutdown input low, and turned on by pulling it high. If this feature is not to be used, the Shutdown input should be tied to VIN to keep the regulator output on at all times. To assure proper operation, the signal source used to drive the Shutdown input must be able to swing above and below the specified turn-on/turn-off voltage thresholds listed as VH and VL, respectively (see Electrical Characteristics). www.national.com In any application where the output may be pulled above the input, an external Schottky diode must be connected from VIN to VOUT (cathode on VIN, anode on VOUT), to limit the reverse voltage across the LP2986 to 0.3V (see Absolute Maximum Ratings). 12 Physical Dimensions inches (millimeters) unless otherwise noted 8-Lead Mini-Small Outline Molded Package, JEDEC NS Package Number MUA08A 13 www.national.com LP2986 Micropower, 200 mA Ultra Low-Dropout Fixed or Adjustable Voltage Regulator Physical Dimensions inches (millimeters) unless otherwise noted (Continued) 8-Lead (0.150” Wide) Molded Small Outline Package, JEDEC NS Package Number M08A LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. National Semiconductor Corporation Americas Tel: 1-800-272-9959 Fax: 1-800-737-7018 Email: [email protected] www.national.com National Semiconductor Europe Fax: +49 (0) 1 80-530 85 86 Email: [email protected] Deutsch Tel: +49 (0) 1 80-530 85 85 English Tel: +49 (0) 1 80-532 78 32 Français Tel: +49 (0) 1 80-532 93 58 Italiano Tel: +49 (0) 1 80-534 16 80 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. 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