LP3986 Dual Micropower 150 mA Ultra Low-Dropout CMOS Voltage Regulators in micro SMD Package General Description Features The LP3986 is a 150 mA dual low dropout regulator designed for portable and wireless applications with demanding performance and board space requirements. The LP3986 is stable with a small 1 µF ± 30% ceramic output capacitor requiring smallest possible board space. n Miniature 8-I/O micro SMD package n Stable with 1µF ceramic and high quality tantalum output capacitors n Fast turn-on n Two independent regulators n Logic controlled enable n Over current and thermal protection The LP3986’s performance is optimized for battery powered systems to deliver ultra low noise, extremely low dropout voltage and low quiescent current independent of load current. Regulator ground current increases very slightly in dropout, further prolonging the battery life. Optional external bypass capacitor reduces the output noise further without slowing down the load transient response. Fast start-up time is achieved by utilizing a speed-up circuit that actively precharges the bypass capacitor. Power supply rejection is better than 60 dB at low frequencies and 55 dB at 10 kHz. High power supply rejection is maintained at low input voltage levels common to battery operated circuits. The LP3986 is available in a micro SMD package. Performance is specified for a −40˚C to +125˚C temperature range. For single LDO applications, please refer to the LP3985 datasheet. Key Specifications n Guaranteed 150 mA output current per regulator n 1nA typical quiescent current when both regulators in shutdown mode n 60 mV typical dropout voltage at 150 mA output current n 115 µA typical ground current n 40 µV typical output noise n 200 µs fast turn-on circuit n −40˚C to +125˚C junction temperature Applications n n n n CDMA cellular handsets GSM cellular handsets Portable information appliances Portable battery applications Typical Application Circuit 20003401 © 2003 National Semiconductor Corporation DS200034 www.national.com LP3986 Dual Micropower 150 mA Ultra Low-Dropout CMOS Voltage Regulators in micro SMD Package May 2003 LP3986 Block Diagram LP3986 20003402 Pin Description Name *micro SMD VOUT2 A1 Function Output Voltage of the second LDO EN2 B1 Enable input for the second LDO BYPASS C1 Bypass capacitor for the bandgap GND C2 Common ground GND C3 Common ground EN1 B3 Enable input for the first LDO VOUT1 A3 Output Voltage of the first LDO VIN A2 Common input for both LDOs * Note: The pin numbering scheme for the micro SMD package was revised in April 2002 to conform to JEDEC standard. Only the pin numbers were revised. No changes to the physical location of the inputs/outputs were made. For reference purposes, the obsolete numbering scheme had VOUT2 as pin 1, EN2 as pin 2, BYPASS as pin 3, GND as pins 4 and 5, EN1 as pin 6, VOUT1 as pin 7, and VIN as pin 8. Connection Diagram 20003404 Top View 8 Bump micro SMD Package See NS Package Number BLA08 www.national.com 2 LP3986 Ordering Information For micro SMD Package (BL has thickness of 0.995mm) Output Voltage (V) Grade Package Marking LP3986 Supplied as 250 Units, Tape and Reel LP3986 Supplied as 3000 Units, Tape and Reel 2.52.8 STD 14 LP3986BL-2528 2.82.8 STD 10 LP3986BL-2828 LP3986BLX-2828 2.852.85 STD 11 LP3986BL-285285 LP3986BLX285285 2.92.9 STD 15 LP3986BL-2929 LP3986BLX-2929 3.03.0 STD 12 LP3986BL-3030 LP3986BLX-3030 3.13.1 STD 13 LP3986BL-3131 LP3986BLX-3131 3.13.3 STD 16 LP3986BL-3133 LP3986BLX-3133 3.33.3 STD 17 LP3986BL-3333 LP3986BLX-3333 LP3986BLX-2528 For micro SMD Package (TL has thickness of 0.600mm) Output Voltage (V) Grade Package Marking 2.52.8 STD 14 LP3986 Supplied as 250 Units, Tape and Reel LP3986TL-2528 LP3986 Supplied as 3000 Units, Tape and Reel LP3986TLX-2528 2.82.8 STD 10 LP3986TL-2828 LP3986TLX-2828 2.852.85 STD 11 LP3986TL-285285 LP3986TLX285285 2.92.9 STD 15 LP3986TL-2929 LP3986TLX-2929 3.03.0 STD 12 LP3986TL-3030 LP3986TLX-3030 3.13.1 STD 13 LP3986TL-3131 LP3986TLX-3131 3.13.3 STD 16 LP3986TL-3133 LP3986TLX-3133 3.33.3 STD 17 LP3986TL-3333 LP3986TLX-3333 20003403 3 www.national.com LP3986 Absolute Maximum Ratings ESD Rating (Note 5) Human Body Model Machine Model (Notes 1, 2) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. VIN, VEN Operating Ratings (Notes 1, 2) −0.3 to 6.5V −0.3 to (VIN+0.3V) ≤ 6.5V VOUT Junction Temperature 150˚C Storage Temperature −65˚C to +150˚C Pad Temp. (Note 3) VIN 364mW 2.5 to 6V 0 to (VIN+ 0.3V) ≤ 6V VEN Junction Temperature −40˚C to +125˚C Thermal Resistance 235˚C Maximum Power Dissipation (Note 4) 2kV 200V θJA 220˚C/W Maximum Power Dissipation (Note 6) 250mW Electrical Characteristics Unless otherwise specified: VIN = VOUT(nom) + 0.5V, CIN = 1 µF, IOUT = 1mA, COUT = 1 µF, CBYPASS = 0.01µF. Typical values and limits appearing in standard typeface are for TJ = 25˚C. Limits appearing in boldface type apply over the entire junction temperature range for operation, −40˚C to +125˚C. (Note 7) (Note 8) Symbol ∆VOUT Parameter Conditions Typ Max −2.5 −3.0 2.5 3.0 % of VOUT(nom) 0.092 0.128 %/V IOUT = 1mA Line Regulation Error (Note 9) VIN = (VOUT(nom) + 0.5V) to 6.0V, IOUT = 1 mA 0.006 Load Regulation Error (Note 10) IOUT = 1mA to 150 mA 0.003 Output AC Line Regulation VIN = VOUT(nom) + 1V, IOUT = 150 mA (Figure 1) 1.5 VIN = 3.1V, f = 1 kHz, IOUT = 50 mA (Figure 2) 60 VIN = 3.1V, f = 10 kHz, IOUT = 50 mA (Figure 2) 50 Both Regulators ON VEN = 1.4V, IOUT = 0 mA 115 200 Both Regulators ON VEN = 1.4V, IOUT = 0 to 150 mA 220 320 One Regulator ON VEN = 1.4V IOUT = 0 mA 75 130 One Regulator ON VEN = 1.4V IOUT = 0 to 150 mA 130 200 VEN = 0.4V, Both Regulators OFF (shutdown) 0.001 2 4 2 100 Power Supply Rejection Ratio IQ Quiescent Current Dropout Voltage (Note 11) IOUT = 1 mA IOUT = 150 mA 0.4 60 ISC Short Circuit Current Limit Output Grounded 600 IOUT(PK) Peak Output Current VOUT ≥ VOUT(nom) - 5% 500 TON Turn-On Time (Note 12) CBYPASS = 0.01 µF 200 4 Units Min Output Voltage Tolerance PSRR www.national.com Limit 0.006 0.01 %/mA mVP-P dB µA mV mA 300 mA µs (Continued) Unless otherwise specified: VIN = VOUT(nom) + 0.5V, CIN = 1 µF, IOUT = 1mA, COUT = 1 µF, CBYPASS = 0.01µF. Typical values and limits appearing in standard typeface are for TJ = 25˚C. Limits appearing in boldface type apply over the entire junction temperature range for operation, −40˚C to +125˚C. (Note 7) (Note 8) Symbol Parameter Conditions Typ Limit Min Max Units en Output Noise Voltage BW = 10 Hz to 100 kHz, COUT = 1µF 40 µVrms ρn(1/f) Output Noise Density f = 120 Hz, COUT = 1µF 1 µV/ IEN Maximum Input Current at EN VEN = 0.4 and VIN = 6V VIL Maximum Low Level Input Voltage at EN VIN = 2.5 to 6V VIH Minimum High Level Input Voltage at EN VIN = 2.5 to 6V Xtalk COUT Crosstalk Rejection ± 10 nA 0.4 1.4 ∆ILoad1 = 150 mA at 1KHz rate ∆ILoad2 = 1 mA ∆VOUT2/∆VOUT1 −60 ∆ILoad2 = 150 mA at 1KHz rate ∆ILoad1 = 1 mA ∆VOUT2/∆VOUT1 −60 V V dB Capacitance (Note 13) 1 22 µF ESR (Note 14) 5 500 mΩ Note 1: 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 2: All voltages are with respect to the potential at the GND pin. Note 3: Additional information on pad temperature can be found in National Semiconductor Application Note (AN-1112). Note 4: The Absolute Maximum power dissipation depends on the ambient temperature and can be calculated using the formula: PD = (TJ - TA)/θJA, Where TJ is the junction temperature, TA is the ambient temperature, and θJA is the junction-to-ambient thermal resistance. The 364mW rating appearing under Absolute Maximum Ratings results from substituting the Absolute Maximum junction temperature, 150˚C, for TJ, 70˚C for TA, and 220˚C/W for θJA. More power can be dissipated safely at ambient temperatures below 70˚C . Less power can be dissipated safely at ambient temperatures above 70˚C. The Absolute Maximum power dissipation can be increased by 4.5mW for each degree below 70˚C, and it must be derated by 4.5mW for each degree above 70˚C. Note 5: The human body model is 100pF discharged through a 1.5kΩ resistor into each pin. The machine model is a 200pF capacitor discharged directly into each pin. Note 6: Like the Absolute Maximum power dissipation, the maximum power dissipation for operation depends on the ambient temperature. The 250mW rating appearing under Operating Ratings results from substituting the maximum junction temperature for operation, 125˚C, for TJ, 70˚C for TA, and 220˚C/W for θJA into (1) above. More power can be dissipated at ambient temperatures below 70˚C . Less power can be dissipated at ambient temperatures above 70˚C. The maximum power dissipation for operation can be increased by 4.5mW for each degree below 70˚C, and it must be derated by 4.5mW for each degree above 70˚C. Note 7: All limits are guaranteed. All electrical characteristics having room temperature limits are tested during production with TJ = 25˚C or correlated using Statistical Quality Control (SQC) methods. All hot and cold limits are guaranteed by correlating the electrical characteristics to process and temperature variations and applying statistical process control. Note 8: The target output voltage, which is labeled VOUT(nom), is the desired voltage option. Note 9: The output voltage changes slightly with line voltage. An increase in the line voltage results in a slight increase in the output voltage and vice versa. Note 10: The output voltage changes slightly with load current. An increase in the load current results in a slight decrease in the output voltage and vice versa. Note 11: Dropout voltage is the input-to-output voltage difference at which the output voltage is 100mV below its nominal value. Note 12: Turn-on time is that between the enable input just exceeding VIH and the output voltage just reaching 95% of its nominal value. Note 13: Range of capacitor values for which the device will remain stable. This electrical specification is guaranteed by design. Note 14: Range of capacitor ESR values for which the device will remain stable. This electrical specification is guaranteed by design. 5 www.national.com LP3986 Electrical Characteristics LP3986 20003408 FIGURE 1. Line Regulation Input Test Signal 20003409 FIGURE 2. PSRR Input Test Signal www.national.com 6 Power Supply Rejection Ratio (CBP = 0.001µF) BP= Power Supply Rejection Ratio (CBP = 0.01µF) 20003410 20003447 Power Supply Rejection Ratio (CBP = 0.1µF) Output Noise Spectral Density 20003448 20003451 Line Transient Response (CBP = 0.001µF) Line Transient Response (CBP = 0.01µF) 20003413 20003449 7 www.national.com LP3986 Typical Performance Characteristics Unless otherwise specified, CIN= COUT 1µF Ceramic, C 0.01µ F, VIN = VOUT + 0.5, TA= 25˚C, both enable pins are tied to VIN LP3986 Typical Performance Characteristics Unless otherwise specified, CIN= COUT 1µF Ceramic, C 0.01µ F, VIN = VOUT + 0.5, TA= 25˚C, both enable pins are tied to VIN (Continued) Load Transient & Cross Talk (VIN = VOUT + 0.2V) Load Transient & Cross Talk (VIN = VOUT + 0.2V) 20003417 20003416 Start-Up Time (CBP = 0.001, 0.01, 0.1µF) Enable Response ( VIN = 4.2V ) 20003411 20003414 Enable Response (VIN = VOUT+ 0.2V) Enable Response 20003450 20003415 www.national.com BP= 8 Output Short Circuit Current at VIN = 6V BP= Output Short Circuit Current at VIN = 3.3V 20003465 20003466 9 www.national.com LP3986 Typical Performance Characteristics Unless otherwise specified, CIN= COUT 1µF Ceramic, C 0.01µ F, VIN = VOUT + 0.5, TA= 25˚C, both enable pins are tied to VIN (Continued) LP3986 Application Hints X7R is recommended over Z5U and Y5 in applications where the ambient temperature will change significantly above or below 25˚C. 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 1µF to 4.7µF 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 Like any low-dropout regulator, the LP3986 requires external capacitors for regulator stability. The LP3986 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 capacitance of ) 1µF is required between the LP3986 input pin and ground (the amount of the capacitance may be increased without limit). This capacitor must be located a distance of not more than 1cm from the input pin and returned to a clean analog 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. NOISE BYPASS CAPACITOR Connecting a 0.01µF capacitor between the CBYPASS pin and ground significantly reduces noise on the regulator output. This cap is connected directly to a high impedance node in the band gap reference circuit. 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 this 0.01µF bypass capacitor is strongly recommended to prevent overshoot on the output during start up. The types of capacitors best suited for the noise bypass capacitor are ceramic and film. High-quality ceramic capacitors with either 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. Unlike many other LDO’s, addition of a noise reduction capacitor does not effect the transient response of the device. There are no requirements for the ESR on the input capacitor, but tolerance and temperature coefficient must be considered when selecting the capacitor to ensure the capacitance will be ) 1µF over the entire operating temperature range. OUTPUT CAPACITOR The LP3986 is designed specifically to work with very small ceramic output capacitors, any ceramic capacitor (temperature characteristics X7R, X5R, Z5U or Y5V) in 1 to 22 µF range with 5mΩ to 500mΩ ESR range is suitable in the LP3986 application circuit. It may also be possible to use tantalum or film capacitors at the output, but these are not as attractive for reasons of size and cost (see next section Capacitor Characteristics). The output capacitor must meet the requirement for minimum amount of capacitance and also have an ESR (Equivalent Series Resistance) value which is within a stable range. ON/OFF INPUT OPERATION The LP3986 is turned off by pulling the VEN pin low, and turned on by pulling it high. If this feature is not used, the VEN pin 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 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. NO-LOAD STABILITY The LP3986 will remain stable and in regulation with no-load (other than the internal voltage divider). This is specially important in CMOS RAM keep-alive applications. CAPACITOR CHARACTERISTICS The LP3986 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 1µF to 4.7µF range, ceramic capacitors are the smallest, least expensive and have the lowest ESR values (which makes them best for eliminating high frequency noise). The ESR of a typical 1µF ceramic capacitor is in the range of 20 mΩ to 40 mΩ, which easily meets the ESR requirement for stability by the LP3986. The ceramic capacitor’s capacitance can vary with temperature. The capacitor type X7R, which operates over a temperature range of -55˚C to +125˚C, will only vary the capacitance to within ± 15%. Most large value ceramic capacitors () 2.2µF) are manufactured with Z5U or Y5V temperature characteristics. Their capacitance can drop by more than 50% as the temperature goes from 25˚C to 85˚C. Therefore, www.national.com FAST ON-TIME The LP3986 outputs are turned on after Vref voltage reaches its final value (1.23V nominal). To speed up this process, the noise reduction capacitor at the bypass pin is charged with an internal 70µA current source. The current source is turned off when the bandgap voltage reaches approximately 95% of its final value. The turn on time is determined by the time constant of the bypass capccitor. The smaller the capacitor value, the shorter the turn on time, but less noise gets reduced. As a result, turn on time and noise reduction need to be taken into design consideration when choosing the value of the bypass capacitor. 10 The wavelengths which have most detrimental effect are reds and infra-reds, which means that the fluorescent lighting used inside most buildings has very little effect on performance. A micro SMD test board was brought to within 1cm of a fluorescent desk lamp and the effect on the regulated output voltage was negligible, showing a deviation of less than 0.1% from nominal. (Continued) 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. For best results during assembly, alignment ordinals on the PC board may be used to facilitate placement of the micro SMD device. MICRO SMD LIGHT SENSITIVITY Exposing the micro SMD device to direct sunlight will cause misoperation of the device. Light sources such as halogen lamps can effect electrical performance if brought near to the device. 11 www.national.com LP3986 Application Hints LP3986 Physical Dimensions inches (millimeters) unless otherwise noted micro SMD, 8 Bump NS Package Number BLA08CCC The dimensions for X1, X2 and X3 are as follows: X1 = 1.55mm X2 = 1.55mm X3 = 0.995mm www.national.com 12 inches (millimeters) unless otherwise noted (Continued) micro SMD, 8 Bump NS Package Number ATL08CCA The dimensions for X1, X2 and X3 are as follows: X1 = 1.55mm X2 = 1.55mm X3 = 0.600mm 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 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 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 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. LP3986 Dual Micropower 150 mA Ultra Low-Dropout CMOS Voltage Regulators in micro SMD Package Physical Dimensions