LMS5214 80mA, Low Dropout Voltage Regulator with Auto Discharge Function in SC70 General Description Features The LMS5214 is a µCap, low dropout voltage regulator with very low quiescent current, 110µA typical, at 80mA load. It also has very low dropout voltage, typically 2mV at light load and 300mV at 80mA. The LMS5214 is an enhanced version of the industry standard LMS5213 with auto discharge function which actively discharges the output voltage to ground when the device is placed in shutdown mode. It provides up to 80mA and consumes a typical of 10nA in disable mode, which helps to extend the battery life. (Typical unless noted) n Space saving SC70 package n Low quiescent current: 70µA n Low dropout voltage: 2mV n Stability with low-ESR ceramic capacitors n Auto discharge n Fast turn-on n Low temperature coefficient n Current and thermal limiting n Zero current in shutdown mode n Pin-to-pin compatible with LMS5213 The LMS5214 is optimized to work with low value, low cost ceramic capacitors. The output typically requires only 470nF of output capacitance for stability. The enable pin can be tied to VIN for easy device layout. Low ground current at full load and small package makes the LMS5214 ideal for portable, battery powered equipment applications with small space requirements. The LMS5214 is available in a space saving 5-pin SC70 package. Performance is specified for the −40˚C to +125˚C temperature range and is available in 2.5V, 2.6V, 2.8V, 2.9V, 3.0V and 3.3V fixed voltages. For other output voltage options, please contact National Semiconductor. Applications n n n n n Cellular Phones Battery-powered equipment Bar code scanner Laptops, notebooks, PDA’s High-efficiency linear power supplies Typical Application 20043120 © 2002 National Semiconductor Corporation DS200431 www.national.com LMS5214 80mA, Low Dropout Voltage Regulator with Auto Discharge Function in SC70 August 2002 LMS5214 Simplified Schematic 20043101 Pin Description Pin Number Pin Name 1 VEN Enable Input Logic, Logic High = Enabled Logic Low = Shutdown 2 NC Not internally connected 3 GND Ground 4 VOUT Output Voltage 5 VIN Input Voltage www.national.com Pin Function 2 LMS5214 Connection Diagram SC70-5 20043121 Top View Ordering Information (For other output voltage options, please contact National Semiconductor). Package Part Number LMS5214IMG-2.5 LMS5214IMGX-2.5 LMS5214IMG-2.6 LMS5214IMGX-2.6 5-Pin SC70 LMS5214IMG-2.8 LMS5214IMGX-2.8 LMS5214IMG-2.9 LMS5214IMGX-2.9 LMS5214IMG-3.0 LMS5214IMGX-3.0 LMS5214IMG-3.3 LMS5214IMGX-3.3 Package Marking Transport Media NSC Drawing 1k Units Tape and Reel L0T 3k Units Tape and Reel 1k Units Tape and Reel L0U 3k Units Tape and Reel 1k Units Tape and Reel L0V MAA05A 3k Units Tape and Reel 1k Units Tape and Reel L0X 3k Units Tape and Reel 1k Units Tape and Reel L0Y 3k Units Tape and Reel 1k Units Tape and Reel L0Z 3k Units Tape and Reel 3 www.national.com LMS5214 Absolute Maximum Ratings (Note 1) Operating Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltages ESD Tolerance (Note 2) VIN Human Body Model VEN 2000V Machine Model Storage Temperature Range 150˚C VIN, VOUT, VEN −40˚C to +125˚C −65˚C to 150˚C Package Thermal Resistance −0.3 TO 6.5V SC70-5 Soldering Information Infrared or Convection (20 sec) Wave Soldering (10 sec) 0V to VIN Junction Temp. Range (Note 3) 200V Junction Temperature 2.5V to 6V 478˚C/W 235˚C 260˚C (lead temp) Electrical Characteristics Unless otherwise specified, all limits guaranteed for TJ = 25˚C, VIN = VOUT + 1V, IL = 1mA, CL = 0.47µF, VEN ≥ 2.0V. Boldface limits apply at the temperature extremes. Symbol Parameter Conditions Min (Note 5) Typ (Note 4) Max (Note 5) Units 3 4 % 50 200 ppm/˚C VO Output Voltage Accuracy -3 -4 ∆VO/∆T Output Voltage Temp. Coefficient (Note 10) ∆VO/VO Line Regulation VIN = VOUT +1V to 6V 0.008 0.3 0.5 % ∆VO/VO Load Regulation IL = 0.1mA to 80mA (Note 6) 0.08 0.3 0.5 % VIN-VO Dropout Voltage (Note 7) IL = 100µA 2 IL = 20mA 70 IL = 50mA 180 150 mV IL = 80mA 300 500 IQ Quiescent Current VEN ≤ 0.4V (Shutdown) 10 100 nA IGND Ground Pin Current IL = 100µA, VEN ≥ 2.0V (active) 70 IL = 20mA, VEN ≥ 2.0V (active) 80 135 µA IL = 80mA, VEN ≥ 2.0V (active) 110 200 400 ILIMIT Current Limit VOUT = 0V 200 ∆VO/∆PD Thermal Regulation (Note 9) 0.05 mA %W Enable Input VIL Enable Input Voltage Level Logic Low (off) Enable Input Current VIL ≤ 0.6V VIH ≥ 2.0V VIH IIL Logic High (on) IIH 0.6 V 0.01 1 µA 0.01 5 µA 2.0 V Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is intended to be functional, but specific performance is not guaranteed. For guaranteed specifications and the test conditions, see the Electrical Characteristics. Note 2: Human body model, 1.5kΩ in series with 100pF. Note 3: The maximum power dissipation is a function of TJ(MAX) , θJA, and TA. The maximum allowable power dissipation at any ambient temperature is PD = (TJ(MAX)–T A)/θJA. All numbers apply for packages soldered directly into a PC board. Note 4: Typical Values represent the most likely parametric norm. Note 5: All limits are guaranteed by testing or statistical analysis. Note 6: Regulation is measured at constant junction temperature using low duty cycle pulse testing. Changes in output voltage due to heating effects are covered by the thermal regulation specification. Note 7: Dropout voltage is defined as the input to output differential at which the output voltage drops 2% below its nominal value measured at 1V differential. Note 8: Ground pin current is the regulator quiescent current plus pass transistor base current. The total current drawn from the supply is the sum of the load current plus the ground pin current. Note 9: Thermal regulation is defined as the change in output voltage at a time “t” after a change in power dissipation is applied, excluding load or line regulation effects. Specifications are for an 80mA load pulse at VIN = 6V for t = 16ms. Note 10: Output voltage temperature coefficient is defined as the worst-case voltage change divided by the total temperature range. www.national.com 4 LMS5214 Typical Characteristics Unless otherwise specified, TA = 25˚C, VOUT = 2.8V, CL = 0.47µF Dropout Voltage vs. Output Current Dropout Voltage vs. Temperature 20043130 20043131 Dropout Characteristics Dropout Characteristics 20043109 20043110 Ground Current vs. Output Current Ground Current vs. Input Voltage 20043127 20043125 5 www.national.com LMS5214 Typical Characteristics Unless otherwise specified, TA = 25˚C, VOUT = 2.8V, CL = 0.47µF Ground Current vs. Temperature (Continued) Short Circuit Current vs. Input Voltage 20043126 20043124 Short Circuit Current vs. Temperature Output Voltage vs. Temperature 20043128 20043129 Load Transient Load Transient 20043106 20043105 www.national.com 6 Line Transient (Continued) Ripple Voltage vs. Frequency 20043102 20043132 Ripple Voltage vs. Frequency Noise Characteristics 20043133 20043108 Enable Characteristics Start Up Characteristics 20043107 20043103 7 www.national.com LMS5214 Typical Characteristics Unless otherwise specified, TA = 25˚C, VOUT = 2.8V, CL = 0.47µF LMS5214 Typical Characteristics Unless otherwise specified, TA = 25˚C, VOUT = 2.8V, CL = 0.47µF (Continued) Start Up Characteristics 20043104 The LMS5214 is designed to work with high quality tantalum capacitors and small ceramic output capacitors. Ceramic capacitors ranging between 470nF to 4.7µF are the smallest and least expensive. Application Information The LMS5214 is a low dropout, linear regulator designed primarily for battery-powered applications. The LMS5214 can be used with low cost ceramic capacitors, typical value of 470nF. No-Load Stability The LMS5214 will remain stable and in regulation with no-load (other than the internal voltage divider). This is especially important in CMOS RAM keep-alive applications. The LMS5214 is an enhanced version of the LMS5213 with auto discharge function which actively discharges the output voltage to ground when the device is placed in shutdown mode As illustrated in the simplified schematics, the LMS5214 consists of a 1.25V reference, error amplifier, P-channel pass transistor and internal feedback voltage divider. The 1.25V reference is connected to the input of the error amp. The error amp compares this reference with the feedback voltage. If the feedback voltage is lower than the reference, the pass transistor gate is pulled lower allowing more current to pass and increasing the output voltage. If the feedback voltage is too high, the pass transistor gate is pulled up allowing less current to pass to the output. The output voltage is fedback through the resistor divider. Additional blocks include short circuit current protection and thermal protection. The LMS5214 features an 80mA P-channel MOSFET transistor. This provides several advantages over similar designs using PNP pass transistors including longer battery life. The P-channel MOSFET requires no base drive, which reduces quiescent current considerably. PNP based regulators waste considerable amounts of current in dropout when the pass transistor saturates. They also have high base drive currents under large loads. The LMS5214 does not suffer from these problems and consumes only the specified quiescent current under light and heavy loads. External Capacitors Like any low-dropout regulators, the LMS5214 requires external capacitors for regulator stability. The LMS5214 is specially designed for portable applications requiring minimum board space and the smallest components. A 1µF capacitor should be placed from VIN to GND if there is more than 10 inches of wire between the input and AC filter or when a battery is used as the input. This capacitor must be located a distance of not more than 1cm from the input pin and returned to a clean analog ground. www.national.com Enable Input The LMS5214 is shut off by pulling the VEN pin below 0.6V; all internal circuitry is powered off and the quiescent current is typically 10nA. Pulling the VEN high above 2V re-enables the device and allows operation. If the shut down feature is not used, the VEN pin should be tied to VIN to keep the regulator output on all the time. Thermal Behavior The LMS5214 regulator has internal thermal shutdown to protect the device from over heating. Under all operating conditions, the maximum junction temperature of the LMS5214 must be below 125˚C. Maximum power dissipation can be calculated based on the output current and the voltage drop across the part. The maximum power dissipation is PD(MAX) = (TJ(MAX) - TA)/θJA θJA is the junction-to-ambient thermal resistance, 478˚C/W for the LMS5214 in the SC70 package. TA is the maximum ambient temperature TJ(MAX) is the maximum junction temperature of the die, 125˚C When operating the LMS5214 at room temperature, the maximum power dissipation is 209mW. The actual power dissipated by the regulator is PD = (VIN-VOUT) IL + VIN IGND The figure below shows the voltage and currents, which are present in the circuit. 8 Fixed Voltage Regulator (Continued) The LMS5214 offers a smaller system solution that is ideal for general-purpose voltage regulation in any handheld device. 20043122 FIGURE 1. Power Dissipation Diagram Substituting PD(MAX), determined above, for PD and solving for the operating condition that are critical to the application will give the maximum operating conditions for the regulator circuit. To prevent the device from entering thermal shutdown, maximum power dissipation cannot be exceeded. 20043120 FIGURE 2. Single-Cell Regulator 9 www.national.com LMS5214 Application Information LMS5214 80mA, Low Dropout Voltage Regulator with Auto Discharge Function in SC70 Physical Dimensions inches (millimeters) unless otherwise noted 5-Pin SC70-5 NSC Package Number MAA05A 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 AND GENERAL COUNSEL 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 Email: [email protected] www.national.com National Semiconductor Europe Fax: +49 (0) 180-530 85 86 Email: [email protected] Deutsch Tel: +49 (0) 69 9508 6208 English Tel: +44 (0) 870 24 0 2171 Français Tel: +33 (0) 1 41 91 8790 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. National Semiconductor Asia Pacific Customer Response Group Tel: 65-2544466 Fax: 65-2504466 Email: [email protected] National Semiconductor Japan Ltd. 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