SP6669AEK-L/TRR3

SP6669 800mA 1.5MHz Synchronous Step Down Converter December 2017 Rev. 3.0.0 GENERAL DESCRIPTION APPLICATIONS • Portable Equipment The SP6669 is a synchronous current mode PWM step down (buck) converter capable of delivering up to 800mA of current. It features a pulse skip mode (PSM) for light load efficiency and a LDO mode for 100% duty cycle. • Battery Operated Equipment • Audio-Video Equipment • Networking & Telecom Equipment With a 2.5V to 6.0V input voltage range and a 1.5MHz switching frequency, the SP6669 allows the use of small surface mount inductors and capacitors ideal for battery powered portable applications. The internal synchronous switch increases efficiency and eliminates the need for an external Schottky diode. Low output voltages are easily supported with the 0.6V feedback reference voltage. FEATURES • Guaranteed 800mA Output Current − Input Voltage: 2.5V to 6.0V • 1.5MHz PWM Current Mode Control − 100% Duty Cycle LDO Mode Operations − Achieves 97% Efficiency Built-in over temperature and output over voltage lock-out protections insure safe operations under abnormal operating conditions. • 0.6V 2% Accurate Reference The SP6669 is offered in a RoHS compliant, “green”/halogen free 5-pin SOT23 package. • 18µA Quiescent Current • Excellent Line/Load Transient Response • Over Temperature Protection • RoHS Compliant “Green”/Halogen Free 5-Pin SOT23 Package TYPICAL APPLICATION DIAGRAM Fig. 1: SP6669 Application Diagram (Adj. version shown) 1/11 Rev.3.0.0 SP6669 800mA 1.5MHz Synchronous Step Down Converter ABSOLUTE MAXIMUM RATINGS OPERATING RATINGS These are stress ratings only and functional operation of the device at these ratings or any other above those indicated in the operation sections of the specifications below is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability. Input Voltage Range VIN ............................... 2.5V to 6.0V Operating Temperature Range ................... -40°C to 85°C Operating Junction Temperature1 ...........................125°C Thermal Resistance θJA .................................. 134.5°C/W Thermal Resistance θJc....................................... 81°C/W Input Voltage VIN ....................................... -0.3V to 6.6V Enable VFB Voltage ....................................... -0.3V to VIN SW Voltage ...................................... -0.3V to (VIN+0.3V) Peak Switch Sink/Source Current ............................ 1.3A Junction Temperature .......................................... 150°C Storage Temperature .............................. -65°C to 150°C Lead Temperature (Soldering, 10 sec) ................... 260°C ESD Rating (HBM - Human Body Model) .................... 2kV ESD Rating (MM - Machine Model) ...........................200V Note 1: TJ is a function of the ambient temperature TA and power dissipation PD (TJ= TA + PD x θJA). ELECTRICAL SPECIFICATIONS Specifications with standard type are for an Operating Junction Temperature of TJ = 25°C only; limits applying over the full Operating Junction Temperature range are denoted by a “•”. Minimum and Maximum limits are guaranteed through test, design, or statistical correlation. Typical values represent the most likely parametric norm at TA = 25°C, and are provided for reference purposes only. Unless otherwise indicated, VIN = 3.6V. Parameter Min. Typ. Max. Units ±30 nA 0.588 0.600 0.612 V • 0.4 %/V • 80 mV 0.6 %/V Feedback Current IVFB Regulated Feedback Voltage VFB Reference Voltage Line Regulation ΔVFB Output Over-Voltage Lockout ΔVOVL 20 50 Output Voltage Line Regulation ΔVOUT Peak Inductor Current IPK 1.2 Output Voltage Load Regulation VLOADREG 2.3 A 0.5 % Conditions VIN=2.5V to 5.5V ΔVOVL = VOVL – VFB (Adj.) • VIN=2.5V to 5.5V VIN=3V, VFB=0.5V Quiescent Current1 IQ 18 Shutdown Current ISHTDWN 0.1 1 µA 1.5 1.8 MHz • VFB=0.6V 750 kHz • VFB=0V or VOUT=0V RDS(ON) of PMOS RPFET 0.24 Ω ISW=100mA RDS(ON) of NMOS RNFET 0.24 Ω ISW=100mA Oscillator Frequency fOSC 1.2 µA VFB=0.65V VEN=0V, VIN=4.2V SW Leakage ILSW ±1 µA Enable Threshold VEN 1.2 V • V • ±1 µA • Shutdown Threshold VEN EN Leakage Current IEN 0.4 VEN=0V, VSW=0V or 5V, VIN=5V Note 1: The dynamic quiescent current is higher due to the gate charge being delivered at the switching frequency. 2/11 Rev. 3.0.0 SP6669 800mA 1.5MHz Synchronous Step Down Converter BLOCK DIAGRAM Fig. 2: SP6669 Block Diagram PIN ASSIGNMENT Fig. 3: SP6669 Pin Assignment 3/11 Rev. 3.0.0 SP6669 800mA 1.5MHz Synchronous Step Down Converter PIN DESCRIPTION Name Pin Number Description EN 1 Enable Pin. Do not leave the pin floating. VEN1.2V: Device enabled GND 2 Ground Signal SW 3 VIN 4 Switching Node Power Supply Pin. Must be decoupled to ground with a 4.7µF or greater ceramic capacitor. VFB 5 Feedback Input Pin. Connect VFB to the center point of the resistor divider. ORDERING INFORMATION(1) Part Number SP6669AEK-L/TRR3 SP6669EB Operating Temperature Range -40°C≤TA≤+85°C Lead-free Package SOT23-5 Yes(2) SP6669 Evaluation Board Packing Method Tape & Reel Note: 1. Refer to www.exar.com/SP6669 for most up-to-date Ordering Information 2. Visit www.exar.com for additional information on Environmental Rating Note that the SP6669 series is packaged in Tape and Reel with a reverse part orientation as per the following diagram 4/11 Rev. 3.0.0 SP6669 800mA 1.5MHz Synchronous Step Down Converter TYPICAL PERFORMANCE CHARACTERISTICS All data taken at VIN = 2.7V to 5.5V, TJ = TA = 25°C, unless otherwise specified - Schematic and BOM from Application Information section of this datasheet. Fig. 4: Efficiency vs Output Current VOUT = 1.2V Fig. 5: Oscillator Frequency vs. Input Voltage Fig. 6: EN Pin Threshold vs. Input Voltage Fig. 7: EN Pin Threshold vs. Temperature Fig. 8: UVLO Threshold vs. Temperature Fig. 9: Output Voltage vs Temperature 5/11 Rev. 3.0.0 SP6669 800mA 1.5MHz Synchronous Step Down Converter Fig. 10: Line Regulation Fig. 11: Load Regulation Fig. 12: Load Transient Response, Iout 250mA to 500mA, Vout = 1.2V Fig. 13: Load Transient Response, Iout 10mA to 500mA, Vout = 1.2V Fig. 14: PSM / PWM Boundaries Fig. 15: Output Voltage Ripple vs Output Current 6/11 Rev. 3.0.0 SP6669 800mA 1.5MHz Synchronous Step Down Converter Fig. 16: Power-ON from EN Pin Fig. 17: Power-OFF from EN Pin Fig. 18: PWM Operation Fig. 19: Short Circuit Response 7/11 Rev. 3.0.0 SP6669 800mA 1.5MHz Synchronous Step Down Converter THEORY OF OPERATION stability, its value can be optimized to balance very low output ripple and circuit size. It is recommended to use an X5R or X7R rated capacitors which have the best temperature and voltage characteristics of all the ceramics for a given value and size. APPLICATIONS SETTING OUTPUT VOLTAGE The output voltage is determined by:  Eq. 4: VOUT = 0.6V ⋅ 1 +  Fig. 20: Typical Application Circuit  THERMAL CONSIDERATIONS INDUCTOR SELECTION Although the SP6669 has an on board over temperature circuitry, the total power dissipation it can support is based on the package thermal capabilities. The formula to ensure safe operation is given in note 1. Inductor ripple current and core saturation are two factors considered to select the inductor value. Eq. 1: ∆I L = R2   R1   V 1 VOUT 1 − OUT f ⋅L VIN     PCB LAYOUT Equation 1 shows the inductor ripple current as a function of the frequency, inductance, VIN and VOUT. It is recommended to set the ripple current between 30% to 40% of the maximum load current. A low ESR inductor is preferred. The following PCB layout guidelines should be taken into account to ensure proper operation and performance of the SP6669: 1- The GND, SW and VIN traces should be kept short, direct and wide. CIN AND COUT SELECTION 2- VFB pin must be connected directly to the feedback resistors. The resistor divider network must be connected in parallel to the COUT capacitor. A low ESR input capacitor can prevent large voltage transients at VIN. The RMS current rating of the input capacitor is required to be larger than IRMS calculated by: Eq. 2: I RMS ≅ I OMAX 3- The input capacitor CIN must be kept as close as possible to the VIN pin. VOUT (VIN − VOUT ) 4- The SW and VFB nodes should be kept as separate as possible to minimize possible effects from the high frequency and voltage swings of the SW node. VIN The ESR rating of the capacitor is an important parameter to select COUT. The output ripple VOUT is determined by:  Eq. 3: ∆VOUT ≅ ∆I L  ESR +   1 8 ⋅ f ⋅ COUT 5- The ground plates of CIN and COUT should be kept as close as possible.    Higher values, lower cost ceramic capacitors are now available in smaller sizes. These capacitors have high ripple currents, high voltage ratings and low ESR that makes them ideal for switching regulator applications. As COUT does not affect the internal control loop 8/11 Rev. 3.0.0 SP6669 800mA 1.5MHz Synchronous Step Down Converter OUTPUT VOLTAGE RIPPLE FOR VIN CLOSE TO VOUT DESIGN EXAMPLE In a single Lithium-Ion battery powered application, the VIN range is about 2.7V to 4.2V. The desired output voltage is 1.8V. When the input voltage VIN is close to the output voltage VOUT, the SP6669 transitions smoothly from the switching PWM converter mode into a LDO mode. The following diagram shows the output voltage ripple versus the input voltage for a 3.3V output setting and a 200mA current load. The inductor value needed can be calculated using the following equation L=  V 1 VOUT 1 − OUT VIN f ⋅ ∆I L     Substituting VOUT=1.8V, VIN=4.2V, ΔIL=180mA to 240mA (30% to 40%) and f=1.3MHz gives 𝐿𝐿 = 2.86𝜇𝜇𝜇𝜇 𝑡𝑡𝑡𝑡 3.81𝜇𝜇𝜇𝜇 A 3.3µH inductor can be chosen with this application. An inductor of greater value with less equivalent series resistance would provide better efficiency. The CIN capacitor requires an RMS current rating of at least ILOAD(MAX)/2 and low ESR. In most cases, a ceramic capacitor will satisfy this requirement. Fig. 20: VOUT Ripple Voltage for VIN decreasing close to VOUT 9/11 Rev. 3.0.0 SP6669 800mA 1.5MHz Synchronous Step Down Converter MECHANICAL DIMENSIONS 5-PIN SOT23 10/11 Rev. 3.0.0 SP6669 800mA 1.5MHz Synchronous Step Down Converter REVISION HISTORY Revision Date 2.0.0 07/15/2011 2.1.0 02/07/2012 2.2.0 11/08/2012 2.2.1 05/13/2016 Reformat of datasheet (New logo) Changed oscillator frequency unit 12/07/2017 Updated IOUT, VIN range, thermal resistance, ∆VOUT, VFB temperature condition, IPK, IQ, fOSC, RDS(ON), package drawing (now Mechanical Dimensions), format and Ordering Information. Added PSM and new graphs. Updated to MaxLinear logo. Removed fixed voltage options. New graphs. 3.0.0 Description Reformat of datasheet Updated package specification Updated Typical Application schematics and Design example Reformat of datasheet (New logo) Updated Absolute Maximum Ratings, Lead Temperature (Soldering, 10 sec) to 260°C Corporate Headquarters: 5966 La Place Court Suite 100 Carlsbad, CA 92008 Tel.:+1 (760) 692-0711 Fax: +1 (760) 444-8598 www.maxlinear.com High Performance Analog 1060 Rincon Circle San Jose, CA 95131 Tel.: +1 (669) 265 6100 Fax: +1 (669) 265 6101 Email: powertechsupport@exar.com www.exar.com The content of this document is furnished for informational use only, is subject to change without notice, and should not be construed as a commitment by MaxLinear, Inc.. MaxLinear, Inc. assumes no responsibility or liability for any errors or inaccuracies that may appear in the informational content contained in this guide. Complying with all applicable copyright laws is the responsibility of the user. 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