LP3995 Micropower 150mA CMOS Voltage Regulator with Active Shutdown General Description Key Specifications The LP3995 linear regulator is designed to meet the requirements of portable battery-powered applications and will provide an accurate output voltage with low noise and low quiescent current. Ideally suited for powering RF/Analog devices, this device will also be used to meet more general circuit needs in which a fast turn-off is essential. n n n n n n n n n For battery powered applications the low dropout and low ground current provided by the device allows the lifetime of the battery to be maximized. The Enable(/Disable) control allows the system to further extend the battery lifetime by reducing the power consumption to virtually zero. The Enable(/Disable) function on the device incorporates an active discharge circuit on the output for faster device shutdown. Where the fast turn-off is not required the LP3999 linear regulator is recommended. The LP3995 also features internal protection against shortcircuit currents and over-temperature conditions. The LP3995 is designed to be stable with small 1.0 µF ceramic capacitors. The small outline of the LP3995 micro SMD package with the required ceramic capacitors can realize a system application within minimal board area. Performance is specified for a −40˚C to +125˚C temperature range. The device is available in micro SMD package and LLP package. For other package options contact your local NSC sales office. The device is available in fixed output voltages in the ranges 1.5V to 3.3V. For availability, please contact your local NSC sales office. 2.5V to 6.0V Input Range Accurate Output Voltage; ± 75mV / 2% 60 mV Typical Dropout with 150 mA Load Virtually Zero Quiescent Current when Disabled Low Output Voltage Noise Stable with a 1 µF Output Capacitor Guaranteed 150 mA Output Current Fast Turn-on; 30 µs (Typ.) Fast Turn-off; 175 µs (Typ.) Features n n n n n n n n 5 pin micro SMD Package 6 pin LLP Package Stable with Ceramic Capacitor Logic Controlled Enable Fast Turn-on Active Disable for Fast Turn-off. Thermal-overload and Short-circuit Protection −40 to +125˚C Junction Temperature Range for Operation Applications n n n n n GSM Portable Phones CDMA Cellular Handsets Wideband CDMA Cellular Handsets Bluetooth Devices Portable Information Appliances Typical Application Circuit 20034901 © 2004 National Semiconductor Corporation DS200349 www.national.com LP3995 Micropower 150mA CMOS Voltage Regulator with Active Shutdown August 2004 LP3995 Block Diagram 20034902 Pin Description 5 pin micro SMD and LLP - 6 Pin No. Symbol micro SMD LLP A1 3 VEN Name and Function Enable Input; Disables the Regulator when ≤ 0.4V. Enables the regulator when ≥ 0.9V B2 2 GND Common Ground C1 6 VOUT Voltage output. Connect this output to the load circuit. C3 1 VIN A3 4 CBYPASS Voltage Supply Input Bypass Capacitor connection. Connect a 0.01 µF capacitor for noise reduction. 5 N/C No internal connection. There should not be any board connection to this pin. Pad GND Ground connection. Connect to ground plane for best thermal conduction. Connection Diagrams micro SMD, 5 Bump Package 20034903 Top View See NS Package Number TLA05 www.national.com 2 LP3995 Connection Diagrams (Continued) LLP- 6 Package (SOT23 Footprint) 20034904 Top View See NS Package Number LDE06A 3 www.national.com LP3995 Ordering Information For micro SMD Package Output Voltage (V) Grade LP3995 Supplied as 250 Units, Tape and Reel LP3995 Supplied as 3000 Units, Tape and Reel 1.5 STD LP3995ITL-1.5 LP3995ITLX-1.5 1.6 STD LP3995ITL-1.6 LP3995ITLX-1.6 1.8 STD LP3995ITL-1.8 LP3995ITLX-1.8 1.9 STD LP3995ITL-1.9 LP3995ITLX-1.9 2.1 STD LP3995ITL-2.1 LP3995ITLX-2.1 2.5 STD LP3995ITL-2.5 LP3995ITLX-2.5 2.8 STD LP3995ITL-2.8 LP3995ITLX-2.8 2.85 STD LP3995ITL-2.85 LP3995ITLX-2.85 3.0 STD LP3995ITL-3.0 LP3995ITLX-3.0 Package Marking For micro SMD Package unleaded Output Voltage (V) Grade LP3995 Supplied as 250 Units, Tape and Reel LP3995 Supplied as 3000 Units, Tape and Reel 1.5 (Note 2) STD LP3995ITL-1.5 LP3995ITLX-1.5 1.6 (Note 2) STD LP3995ITL-1.6 LP3995ITLX-1.6 1.8 (Note 2) STD LP3995ITL-1.8 LP3995ITLX-1.8 1.9 (Note 2) STD LP3995ITL-1.9 LP3995ITLX-1.9 2.1 (Note 2) STD LP3995ITL-2.1 LP3995ITLX-2.1 2.5 (Note 2) STD LP3995ITL-2.5 LP3995ITLX-2.5 2.8 (Note 2) STD LP3995ITL-2.8 LP3995ITLX-2.8 3.0 (Note 2) STD LP3995ITL-3.0 LP3995ITLX-3.0 Package Marking For LLP- 6 Package Output Voltage (V) Grade LP3995 Supplied as 1000 Units, Tape and Reel LP3995 Supplied as 4500 Units, Tape and Reel Package Marking 1.5 STD LP3995ILD-1.5 LP3995ILDX-1.5 LO20B 1.6 STD LP3995ILD-1.6 LP3995ILDX-1.6 LO21B 1.8 STD LP3995ILD-1.8 LP3995ILDX-1.8 LO22B 1.9 (Note 2) STD LP3995ILD-1.9 LP3995ILDX-1.9 LO23B 2.1 (Note 2) STD LP3995ILD-2.1 LP3995ILDX-2.1 LO24B 2.5 (Note 2) STD LP3995ILD-2.5 LP3995ILDX-2.5 LO25B 2.8 STD LP3995ILD-2.8 LP3995ILDX-2.8 LO26B 3.0 STD LP3995ILD-3.0 LP3995ILDX-3.0 LO30B 3.3 (Note 2) STD LP3995ILD-3.3 LP3995ILDX-3.3 LO31B Note 1: Available in sample quantities only Note 2: For availability contact your local sales office www.national.com 4 Operating Ratings (Note 3) (Notes 3, 4) Input Voltage (VIN) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Enable Input Voltage Input Voltage (VIN) −0.3 to 6.5V Output Voltage −0.3 to (VIN + 0.3V) to 6.5V (max) Enable Input Voltage 0 to 6.0V Junction Temperature −40 to +125˚C Ambient Temperature Range(Note 7) -40 to 85˚C Thermal Properties(Note 8) −0.3 to 6.5V Junction Temperature 2.5 to 6.0V Junction to Ambient Thermal Resistance 150˚C Lead/Pad Temperature (Note 5) θJA (LLP pkg.) micro SMD 260˚C LLP 235˚C Storage Temperature 88˚C/W θJA (micro SMD pkg.) 255˚C/W −65 to +150˚C Continuous Power Dissipation(Note 7) Internally Limited ESD (Note 9) Human Body Model 2 kV Machine Model 200V Electrical Characteristics Unless otherwise noted, VEN = 1.5, VIN = VOUT + 1.0V, CIN = 1 µF, IOUT = 1 mA, COUT = 1 µF, cBP = 0.01 µF. Typical values and limits appearing in normal type apply for TJ = 25˚C. Limits appearing in boldface type apply over the full temperature range for operation, −40 to +125˚C. (Notes 14, 15) Symbol VIN Parameter Conditions Typical Input Voltage Limit Min Max 2.5 6.0 -50 50 -75 75 -3.5 3.5 Units V DEVICE OUTPUT: 1.5 ≤ VOUT < 1.8V ∆VOUT PSRR Output Voltage Tolerance IOUT = 1 mA Line Regulation Error VIN = (VOUT(NOM)+1.0V) to 6.0V, IOUT = 1 mA micro SMD Load Regulation Error IOUT = 1 mA to 150 mA LLP Load Regulation Error IOUT = 1 mA to 150 mA Power Supply Rejection Ratio (Note 11) 10 75 70 125 f = 1 kHz, IOUT = 1 mA 55 f = 10 kHz, IOUT = 1 mA 53 mV mV/V µV/mA µV/mA dB DEVICE OUTPUT: 1.8 ≤ VOUT < 2.5V ∆VOUT PSRR Output Voltage Tolerance IOUT = 1 mA -50 50 −75 75 mV microSMDLine Regulation Error VIN = (VOUT(NOM)+1.0V) to 6.0V, IOUT = 1 mA −2.5 2.5 mV/V LLP Line Regulation Error VIN = (VOUT(NOM)+1.0V) to 6.0V, IOUT = 1 mA −3.5 3.5 mV/V micro SMD Load Regulation Error IOUT = 1 mA to 150 mA LLP Load Regulation Error IOUT = 1 mA to 150 mA Power Supply Rejection Ratio (Note 11) f = 1 kHz, IOUT = 1 mA 55 f = 10 kHz, IOUT = 1 mA 50 5 10 75 80 125 µV/mA µV/mA dB www.national.com LP3995 Absolute Maximum Ratings LP3995 Electrical Characteristics (Continued) Unless otherwise noted, VEN = 1.5, VIN = VOUT + 1.0V, CIN = 1 µF, IOUT = 1 mA, COUT = 1 µF, cBP = 0.01 µF. Typical values and limits appearing in normal type apply for TJ = 25˚C. Limits appearing in boldface type apply over the full temperature range for operation, −40 to +125˚C. (Notes 14, 15) Symbol Parameter Conditions Typical Limit Min Max Units DEVICE OUTPUT: 2.5 ≤ VOUT ≤ 3.3V ∆VOUT PSRR Output Voltage Tolerance IOUT = 1 mA -2 2 −3 3 % of VOUT(NOM) −0.1 0.1 %/V 0.0004 0.002 %/mA 0.002 0.005 %/mA Line Regulation Error VIN = (VOUT(NOM)+1.0V) to 6.0V, IOUT = 1 mA micro SMD Load Regulation Error IOUT = 1 mA to 150 mA LLP Load Regulation Error IOUT = 1 mA to 150 mA Dropout Voltage IOUT = 1 mA 0.4 2 IOUT = 150 mA 60 100 f = 1 kHz, IOUT = 1 mA 60 f = 10 kHz, IOUT = 1 mA 50 Power Supply Rejection Ratio (Note 11) mV dB FULL VOUT RANGE ILOAD Load Current (Notes 10, 11) IQ Quiescent Current VEN = 1.5V, IOUT = 0 mA 85 150 VEN = 1.5V, IOUT = 150 mA 140 200 0.003 1.5 0 VEN = 0.4V µA µA ISC Short Circuit Current Limit 450 mA EN Output Noise Voltage ((Note 11)) BW = 10 Hz to 100 kHz, VIN = 4.2V, IOUT = 1mA 25 µVrms TSHUTDOWN Thermal Shutdown Temperature 160 ˚C Hysteresis 20 ENABLE CONTROL CHARACTERISTICS IEN Maximum Input Current at VEN Input VIL Low Input Threshold VIH High Input Threshold VEN = 0.0V and VIN = 6.0V 0.001 µA 0.4 0.9 V V TIMING CHARACTERISTICS TON Turn On Time (Note 11) To 95% Level (Note 12) 30 µs TOFF Turn Off Time (Note 11) To 5% Level (Note 13) 175 µs Note 3: Absolute Maximum Ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions under which operation of the device is guaranteed. Operating Ratings do not imply guaranteed performance limits. For guaranteed performance limits and associated test conditions, see the Electrical Characteristics tables. Note 4: All voltages are with respect to the potential at the GND pin. Note 5: For information regarding micro SMD and LLP packages please refer to the following application notes; AN-1112 Micro SMD Package Wafer Level Chip Scale Package, AN-1187. Leadless Leadframe Package. Note 6: Internal Thermal shutdown circuitry protects the device from permanent damage. Note 7: In applications where high power dissipation and/or poor thermal resistance is present, the maximum ambient temperature may have to be derated. Maximum ambient temperature (TA(max)) is dependant on the maximum operating junction temperature (TJ(max-op)), the maximum power dissipation (PD(max)), and the junction to ambient thermal resistance in the application (θJA). This relationship is given by :- TA(max) = TJ(max-op) − (PD(max) x θJA) Note 8: Junction to ambient thermal resistance is highly dependant on the application and board layout. In applications where high thermal dissipation is possible, special care must be paid to thermal issues in the board design. Note 9: The human body model is an 100 pF discharge through a 1.5 kΩ resistor into each pin. The machine model is a 200 pF capacitor discharged directly into each pin. Note 10: The device maintains a stable, regulated output voltage without load. Note 11: This electrical specification is guaranteed by design. Note 12: Time from VEN = 0.9V to VOUT = 95% (VOUT(NOM)) Note 13: Time from VEN = 0.4V to VOUT = 5% (VOUT(NOM)) www.national.com 6 (Continued) Note 14: All limits are guaranteed. All electrical characteristics having room-temperature limits are tested during production at TJ = 25˚C or correlated using Statistical Quality Control methods. Operation over the temperature specification is guaranteed by correlating the electrical characteristics to process and temperature variations and applying statistical process control. Note 15: VOUT(NOM) is the stated output voltage option for the device. Recommended Output Capacitor Symbol COUT Parameter Output Capacitor Conditions Capacitance (Note 16) VALUE 1.0 ESR Limit Min Max 0.70 5 Units µF 500 mΩ Note 16: The capacitor tolerance should be ± 30% or better over the temperature range. The recommended capacitor type is X7R however, dependant on the application X5R, Y5V, and Z5U can also be used. Input Test Signals 20034906 FIGURE 1. Line Transient Response Input Test Signal 20034907 FIGURE 2. PSRR Input Test Signal 7 www.national.com LP3995 Electrical Characteristics LP3995 Typical Performance Characteristics Unless otherwise specified, CIN = COUT = 1.0 µF Ceramic, VIN = VOUT + 1.0V, TA = 25˚C, Enable pin is tied to VIN. Ground Current vs Load Current (1.8V VOUT) Output Voltage Change vs Temperature 20034910 20034911 Ground Current vs VIN @ 25˚C Ground Current vs Load Current (2.8V VOUT) 20034912 20034913 Ground Current vs VIN @ 125˚C Dropout vs Load Current 20034915 20034914 www.national.com 8 = VOUT + 1.0V, TA = 25˚C, Enable pin is tied to VIN. (Continued) Short Circuit Current Line Transient Response (VOUT = 2.8V) 20034916 20034917 Ripple Rejection (VOUT = 1.8V) Ripple Rejection (VOUT = 2.8V) 20034918 20034919 Enable Start-Up Time (VOUT = 2.8V) Enable Start-Up Time (VOUT = 2.8V) 20034920 20034921 9 www.national.com LP3995 Typical Performance Characteristics Unless otherwise specified, CIN = COUT = 1.0 µF Ceramic, VIN LP3995 Typical Performance Characteristics Unless otherwise specified, CIN = COUT = 1.0 µF Ceramic, VIN = VOUT + 1.0V, TA = 25˚C, Enable pin is tied to VIN. (Continued) Enable Start-Up Time (VOUT = 1.8V) Enable Start-Up Time (VOUT = 1.8V) 20034922 20034923 Turn-Off Time (VOUT = 2.8V) Turn-Off Time (VOUT = 1.8V) 20034924 20034925 Load Transient Response (VOUT = 2.8V) Load Transient Response (VOUT = 1.8V) 20034926 20034927 www.national.com 10 POWER DISSIPATION AND DEVICE OPERATION The permissible power dissipation for any package is a measure of the capability of the device to pass heat from the power source, the junctions of the IC, to the ultimate heat sink, the ambient environment. Thus the power dissipation is dependent on the ambient temperature and the thermal resistance across the various interfaces between the die and ambient air. The Thermal Resistance figure It may also be possible to use tantalum or film capacitors at the device output, VOUT, but these are not as attractive for reasons of size and cost (see the section Capacitor Characteristics). Re-stating the equation in (Note 7) in the electrical specification section, the allowable power dissipation for the device in a given package can be calculated: The output capacitor must meet the requirement for the minimum value of capacitance and also have an ESR value that is within the range 5 mΩ to 500 mΩ for stability. NO-LOAD STABILITY The LP3995 will remain stable and in regulation with no external load. This is an important consideration in some circuits, for example CMOS RAM keep-alive applications. With a θJA = 255˚C/W, the device in the micro SMD package returns a value of 392 mW with a maximum junction temperature of 125˚C. With a θJA = 88˚C/W, the device in the LLP package returns a value of 1.136 mW with a maximum junction temperature of 125˚C. The actual power dissipation across the device can be represented by the following equation: PD = (VIN − VOUT) x IOUT. This establishes the relationship between the power dissipation allowed due to thermal consideration, the voltage drop across the device, and the continuous current capability of the device. These two equations should be used to determine the optimum operating conditions for the device in the application. CAPACITOR CHARACTERISTICS The LP3995 is designed to work with ceramic capacitors on the output to take advantage of the benefits they offer. For capacitance values in the range of 1 µF to 4.7 µF, ceramic capacitors are the smallest, least expensive and have the lowest ESR values, thus making them best for eliminating high frequency noise. The ESR of a typical 1 µF ceramic capacitor is in the range of 20 mΩ to 40 mΩ, which easily meets the ESR requirement for stability for the LP3995. The temperature performance of ceramic capacitors varies by type. Most large value ceramic capacitors ( ≥ 2.2 µF) are manufactured with Z5U or Y5V temperature characteristics, which results in the capacitance dropping by more than 50% as the temperature goes from 25˚C to 85˚C. A better choice for temperature coefficient in a ceramic capacitor is X7R. This type of capacitor is the most stable and holds the capacitance within ± 15% over the temperature range. Tantalum capacitors are less desirable than ceramic for use as output capacitors because they are more expensive when comparing equivalent capacitance and voltage ratings in the 1 µF to 4.7 µF range. Another important consideration is that tantalum capacitors have higher ESR values than equivalent size ceramics. This means that while it may be possible to find a tantalum capacitor with an ESR value within the stable range, it would have to be larger in capacitance (which means bigger and more costly) than a ceramic capacitor with the same ESR value. It should also be noted that the ESR of a typical tantalum will increase about 2:1 as the temperature goes from 25˚C down to −40˚C, so some guard band must be allowed. EXTERNAL CAPACITORS In common with most regulators, the LP3995 requires external capacitors to ensure stable operation. The LP3995 is specifically designed for portable applications requiring minimum board space and smallest components. These capacitors must be correctly selected for good performance. INPUT CAPACITOR An input capacitor is required for stability. It is recommended that a 1.0 µF capacitor be connected between the LP3995 input pin and ground (this capacitance value may be increased without limit). This capacitor must be located a distance of not more than 1 cm from the input pin and returned to a clean analogue ground. Any good quality ceramic, tantalum, or film capacitor may be used at the input. Important: Tantalum capacitors can suffer catastrophic failures due to surge current when connected to a lowimpedance source of power (like a battery or a very large capacitor). If a tantalum capacitor is used at the input, it must be guaranteed by the manufacturer to have a surge current rating sufficient for the application. There are no requirements for the ESR (Equivalent Series Resistance) on the input capacitor, but tolerance and temperature coefficient must be considered when selecting the capacitor to ensure the capacitance will remain ≅ 1.0 µF over the entire operating temperature range. NOISE BYPASS CAPACITOR A bypass capacitor should be connected between the CBP pin and ground to significantly reduce the noise at the regulator output. This device pin connects directly to a high impedance node within the bandgap reference circuitry. Any significant loading on this node will cause a change on the regulated output voltage. For this reason, DC leakage current through this pin must be kept as low as possible for best output voltage accuracy. The use of a 0.01uF bypass capacitor is strongly recommended to prevent overshoot on the output during start-up. 11 www.national.com LP3995 OUTPUT CAPACITOR The LP3995 is designed specifically to work with very small ceramic output capacitors. A ceramic capacitor (dielectric types Z5U, Y5V or X7R) in the 1.0 [to 10 µF] range, and with ESR between 5 mΩ to 500 mΩ, is suitable in the LP3995 application circuit. For this device the output capacitor should be connected between the VOUT pin and ground. Application Hints LP3995 Application Hints within the reference block allowing a very fast ramp of the output voltage to reach the target voltage. (Continued) The types of capacitors best suited for the noise bypass capacitor are ceramic and film. High quality ceramic capacitors with NPO or COG dielectric typically have very low leakage. Polypropolene and polycarbonate film capacitors are available in small surface-mount packages and typically have extremely low leakage current. micro SMD MOUNTING The micro SMD package requires specific mounting techniques which are detailed in National Semiconductor Application Note AN-1112. Referring to the section Surface Mount Technology (SMT) Assembly Considerations, it should be noted that the pad style which must be used with the 5 pin package is NSMD (non-solder mask defined) type. For best results during assembly, alignment ordinals on the PC board may be used to facilitate placement of the micro SMD device. Unlike many other LDO’s, the addition of a noise reduction capacitor does not effect the transient response of the device. ENABLE OPERATION The LP3995 may be switched ON or OFF by a logic input at the ENABLE pin, VEN. A high voltage at this pin will turn the device on. When the enable pin is low, the regulator output is off and the device typically consumes 3 nA. If the application does not require the shutdown feature, the VEN pin should be tied to VIN to keep the regulator output permanently on. To ensure proper operation, the signal source used to drive the VEN input must be able to swing above and below the specified turn-on/off voltage thresholds listed in the Electrical Characteristics section under VIL and VIH. micro SMD LIGHT SENSITIVITY Exposing the micro SMD device to direct sunlight will cause incorrect operation of the device. Light sources such as halogen lamps can affect electrical performance if they are situated in proximity to the device. Light with wavelengths in the red and infra-red part of the spectrum have the most detrimental effect thus the fluorescent lighting used inside most buildings has very little effect on performance. Tests carried out on a micro SMD test board showed a negligible effect on the regulated output voltage when brought within 1 cm of a fluorescent lamp. A deviation of less than 0.1% from nominal output voltage was observed. FAST TURN OFF AND ON The controlled switch-off feature of the device provides a fast turn off by discharging the output capacitor via an internal FET device. This discharge is current limited by the RDSon of this switch. Fast turn-on is guaranteed by control circuitry www.national.com 12 LP3995 Physical Dimensions inches (millimeters) unless otherwise noted micro SMD, 5 Bump, Package (TLA05) NS Package Number TLA05ADA The dimensions for X1, X2 and X3 are given as: X1 = 1.006 +/− 0.03mm X2 = 1.438 +/− 0.03mm X3 = 0.600 +/− 0.075mm 13 www.national.com LP3995 Micropower 150mA CMOS Voltage Regulator with Active Shutdown Physical Dimensions inches (millimeters) unless otherwise noted (Continued) LLP, 6 Lead, Package (SOT23 Land) NS Package Number LDE06A 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. 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. BANNED SUBSTANCE COMPLIANCE National Semiconductor certifies that the products and packing materials meet the provisions of the Customer Products Stewardship Specification (CSP-9-111C2) and the Banned Substances and Materials of Interest Specification (CSP-9-111S2) and contain no ‘‘Banned Substances’’ as defined in CSP-9-111S2. National Semiconductor Americas Customer Support Center Email: [email protected] Tel: 1-800-272-9959 www.national.com National Semiconductor Europe Customer Support Center 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 National Semiconductor Asia Pacific Customer Support Center Email: [email protected] National Semiconductor Japan Customer Support Center Fax: 81-3-5639-7507 Email: [email protected] Tel: 81-3-5639-7560 National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.