SI9176DM-T1

Si9176 Vishay Siliconix High Performance Step-Down DC-DC Converter With Adjustable Output Voltage D D D D D D D D D D D D D FEATURES 2-MHz PWM Operation Integrated MOSFET Switches 2.6-V to 6.0-V Input Voltage Range Minimal Number of External Components Up to 96% conversion efficiency 600-mA Load Capability 100% Duty Cycle Allows Low Dropout Integrated Compensation Circuit Over-Current Protection Shutdown Current < 2 mA Thermal Shutdown Integrated UVLO 10-Pin MSOP and Space Saving MLP33 Packaging D User Selectable PWM, PSM, or AUTO Mode D PSM Frequency w20 kHz for Inaudible Harmonics APPLICATIONS D D D D D D D D D W-CDMA Cell Phone PDAs/Palmtop PCs LCD Modules Portable Image Scanners GPS Receivers Smart Phones MP3 Players 3G Cell Phone Digital Cameras DESCRIPTION The Si9176 is a high efficiency 600-mA step down converter with internal low on resistance power MOSFET switch and synchronous rectifier transistors. It is designed to convert one cell LiIon battery or three cell alkaline battery voltages to a dynamically adjustable dc output. The integrated high frequency error amplifier with internal compensation minimizes external components. In order to insure efficient conversion throughout the entire load range, PWM (pulse width modulation), PSM (pulse skipping mode) or Auto mode can be selected. In PWM mode, 2-MHz switching permits use of small external inductor and capacitor sizes allowing one of the smallest solutions. PSM mode provides increased efficiency at light loads. In PSM mode the oscillator frequency is kept above 20 kHz to avoid audio band interference. When operating in Auto mode, the converter automatically selects operating in either PWM or PSM mode according to load current demand. The Si9176 is available in the10-pin MSOP and the even smaller MLP33 package and is specified to operate over the industrial temperature range of –40_C to 85_C. The Si9176 packaged in the MLP33 package is available in both standard and lead (Pb)-free. TYPICAL APPLICATIONS CIRCUIT BATTERY CIN 10 mF VIN VDD LX 2.2 mH VOUT Si9176 PGND COUT 4.7 mF R1 FB ENABLE PWM/PSM/AUTO SD MODE REF AGND REF R2 Document Number: 71753 S-41148—Rev. C, 14-Jun-04 www.vishay.com 1 Si9176 Vishay Siliconix ABSOLUTE MAXIMUM RATINGS Voltages Referenced to AGND = 0 V VIN, VDD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.2 V Lx, SD, MODE, FB, CREF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 to 6.2 V (or to VDD )0.3 V whichever is less) GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.3 to +0.3 V ESD Rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 kV Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −65 to 125_C Operating Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150_C Power Dissipation (Package)a 10-pin MSOPb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 481 mW 10-pin MLP33 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 915 mW Thermal Impedance (QJA) 10-Pin MSOP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135_C/W 10-Pin MLP33 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71_C/W Peak Inductor Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.8 A Notes a. Device mounted with all leads soldered or welded to PC board. b. Derate 7.4 mW/_C above 85_C. c. Derate 14 mW/_C above 85_C. Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. RECOMMENDED OPERATING RANGE VIN Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.6 V to 5.5 V CIN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 mF Ceramic COUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.7 mF Ceramic Inductor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.2 mH Operating Load Current PWM Mode . . . . . . . . . . . . . . . . . . . . . . 0 to 600 mA Operating Load Current PSM Mode . . . . . . . . . . . . . . . . . . . . . . . 0 to 150 mA SPECIFICATIONS Parameter Modef Symbol Test Conditions Unless Specified −40_C to 85_C, VIN = VDD,, CIN = 10 mF, COUT = 4.7 mF L = 2.2 mH, 2.6 V v VIN v 5.5 V, R1 = 11.3 kW, R2 = 20 kW Limits Mina Typb Maxa Unit Under Voltage Lockout (UVLO) Under Voltage Lockout (turn-on) Hysteresis VIN rising 2.3 0.1 2.5 V Shutdown (SD) Logic HIGH Logic LOW Delay to Outputc Pull Down VSDH VSDL ten ISD Settle Within $2% accuracy SD rising rising tr < 1 ms Input at VIN RL = 3.3 W RL = 51 W 100 1.6 0.4 100 V ms mA Mode Selection Tri-Level Logic (MODE) MODE Pin HIGH MODE Pin LOW Mode Pin Input Current PWM Auto MODE = GND MODE = VIN −5 5 VIN −0.4 VIN 0.4 V mA Oscillator Frequency fOSC 1.6 2 2.4 MHz Error Amplifier (FB Pin) FB Voltage Accuracy Power Supply Rejection Input Bias Current VFB PSRR IFB VIN = 2.6 V to 5.5 VDC VFB = 1.25 V −1 TA = 25_C TA = −40 to 85_C 1.190 1.173 60 0.01 1 1.215 1.240 1.257 V db mA www.vishay.com 2 Document Number: 71753 S-41148—Rev. C, 14-Jun-04 Si9176 Vishay Siliconix SPECIFICATIONS Parameter Modef Converter Operation Maximum Output Current Maximum Output Current Dropout Voltagee Closed Loop Bandwidth Load Regulationc Line Regulation PWM PSM PWM PSM IAUpk ILpk rDS( ) DS(on) VIN = 3.6 V 6 0.05 0 05 W COUT(ESR) VIN = 3.6 V, VOUT = 3.3 V 6V 3 IOUT w 30 mA IOUT = 600 mA IOUT = 30 mA IOUT = 600 mA IOUT = 30 mA 20 PWM PSM ILOAD ILOAD VDD BW VIN = 3.6 V .6 VOUT = 1.9 V @ 25_C IOUT = 30 mA to 600 mA IOUT = 30 mA to 75 mA VIN = 3.6 V VIN = 3.6 V VIN = 2.6 V, IOUT = 600 mA 190 300 0.5 0.25 "0.1 "0.1 200 1500 250 250 60 80 90 80 600 150 300 mA mA mV kHz % %/V mA mW mVp-p % kHz Test Conditions Unless Specified Symbol −40_C to 85_C, VIN = VDD,, CIN = 10 mF, COUT = 4.7 mF L = 2.2 mH, 2.6 V v VIN v 5.5 V, R1 = 11.3 kW, R2 = 20 kW Limits Mina Typb Maxa Unit VOUT = 3.0 V, VIN = 3.5 V to 5 5 V 0V 5 5.5 PWM/PSM Switch Threshold Current Maximum Inductor Peak Current Limit On Resistance Output Ripple Voltage Efficiency Frequency P-Channel N-Channel PWM PSM PWM PSM PSM Supply Current Input Supply Current Shutdown Supply Current PWM PSM ISUPPLY (VDD & VIN) ISD IOUT = 0 mA VIN = 3.6 V (not switching FB = GND) A, 6 switching, SD = Low 450 400 2 750 mA Thermal Shutdown Thermal Shutdown Temperaturec Thermal Hysteresisc TJ(S/D) 165 20 _C Notes a. The algebraic convention whereby the most negative value is a minimum and the most positive a maximum, is used in this data sheet. b. Typical values are for DESIGN AID ONLY, not guaranteed or subject to production testing. c. Guaranteed by design. d. Settling times, ts, apply after ten. e. Bypass is a device mode of operation, in which, the device is in 100% duty cycle. Bypass operation is possible in either PWM or PSM. f. Operating modes are controlled with the MODE pin where Auto mode = MODE = LOW, PWM Mode = MODE = HIGH, and PSM mode = MODE = OPEN. Document Number: 71753 S-41148—Rev. C, 14-Jun-04 www.vishay.com 3 Si9176 Vishay Siliconix PIN CONFIGURATION MSOP-10 LX AGND FB VDD REF 1 2 3 4 5 10 9 8 7 6 MLP33 PGND VIN AGND SD MODE LX AGND FB VDD REF 10 9 8 7 6 PGND VIN AGND SD MODE 2 3 4 5 Top View Top View PIN DESCRIPTION Pin Number 1 2 3 4 5 Name LX AGND FB VDD REF Inductor connection Low power analog ground Output voltage feedback Input supply voltage for the analog circuit. Function Internal reference, no connection should be made to this pin. Used to select switching mode of the buck converter PWM/PSM Pin Logic: 6 MODE MODE Pin VIN Open GND Operating Mode PWM PSM AUTO 7 8 9 10 SD AGND VIN PGND Logic low disables IC and reduces quiescent current to below 2 mA Must be connected to AGND. Input supply voltage Low impedance power ground ORDERING INFORMATION MSOP-10 Standard Part Number Si9176DH-T1 MLP33 Temperature −40 to 85_C Marking 9176 Standard Part Number Si9176DM-T1 Lead (Pb)-Free Part Number Si9176DM-T1—E3 Marking 9176 Temperature −40 to 85_C Additional voltage options are available. Eval Kit Si9176DB Temperature Range −40 to 85_C Board Surface Mount www.vishay.com 4 Document Number: 71753 S-41148—Rev. C, 14-Jun-04 Si9176 Vishay Siliconix FUNCTIONAL BLOCK DIAGRAM VDD Si9176 VIN PMOS Current Sense Error Amplifier − + Clamp − + FB REF PWM Comparator PWM and Pulse Skipping Logic LX To IC Bias Voltage Reference, UVLO 2 MHz Oscillator AGND AGND MODE SD PGND DETAIL DESCRIPTION General The Si9176 is a high efficiency synchronous dc-dc converter that is ideally suited for lithium ion battery or three cell alkaline applications, as well as step-down of 3.3-V or 5.0-V supplies. The major blocks of the Si9176 are shown in the Functional Block Diagram. The 0.25-W internal MOSFETs switching at a frequency of 2-MHz minimize PC board space while providing high conversion efficiency and performance. The high frequency error-amplifier with built-in loop compensation minimizes external components and provides rapid output settling times of