Solved by SP7651 TM Wide Input Voltage Range 3Amp 900kHz Buck Regulator FEATURES SP7651 2.5V to 20V Step Down Achieved Using Dual Input DFN PACKAGE 7mm x 4mm Output Voltage down to 0.8V PGND 3A Output Capability (Up to 5A with Air Flow) 26 1 LX BOTTOM VIEW Built in Low R Power FETs (40 m typ) 25 2 PGND DSON LX Heatsink Pad 1 24 Connect to Lx 3 PGND Highly Integrated Design, Minimal Components LX Pin 27 23 4 GND 900 kHz Fixed Frequency Operation LX 22 5 VFB UVLO Detects Both V and V VCC CC IN 6 21 COMP Over Temperature Protection GND Heatsink Pad 2 20 7 Connect to GND UVIN Short Circuit Protection with Auto-Restart GND Solved by 8 19 GND Wide BW Amp Allows Type II or III Compensation GND Pin 28 18 9 SS Programmable Soft Start BST 17 10 VIN Fast Transient Response NC Heatsink Pad 3 16 11 VIN High Efficiency: Greater than 92% Possible LX Connect to VIN 15 12 LX VIN Asynchronous Start-Up into a Pre-Charged Output Pin 29 14 13 LX VIN Small 7mm x 4mm DFN Package TM U.S. Patent 6,922,04 DESCRIPTION The SP7651 is a high voltage synchronous step-down switching regulator optimized for high efficiency. The part is designed to be especially attractive for dual supply, 2V step down with 5V used to power the controller. This lower V voltage minimizes power dissipation in the part. The SP765 is designed to provide a fully integrated CC buck regulator solution using a fixed 900kHz frequency, PWM voltage mode architecture. Protection features include UVLO, thermal shutdown and output short circuit protection. The SP765 is available in the space saving 7mm X 4mm DFN package. TYPICAL APPLICATION CIRCUIT U SP7651 L 26 PGND LX VOUT 4.7uH, Irate=3.87A 2 25 Rz3 Rz2 PGND LX 3.3V Cz2 7. 5k , 3 24 0-3A PGND LX +5V 1% , 000pF 5 k,1% C3 4 23 GND LX VCC R 22uF CP 5 22 68. k , % VFB VCC 6.3V Cz3 22pF 6 2 5 0pF COMP GND CVCC 7 20 2.2uF UVIN GND CF ENABLE 8 9 0 0pF GND GND DBST 9 8 RSET SS BST 2 .5k , % 0 7 VIN NC SD101AWS CSS (note 2) 5 nF 6 VIN LX CBST 2 5 VIN LX 6800pF 3 4 VIN LX VIN 12V fs=900Khz C Notes: 22uF 1. U1 Bottom-Side Layout should 16V have three contacts isolated from one another: Vin, SWNODE, and GND. GND 2. RSET=54.48/(Vout-0.8V) (KOhm) Rev J: 3/4/07 SP765 Wide Input Voltage Range 3A, 900kHz, Buck Regulator Copyright 2007 Sipex Corporation ABSOLUTE MAXIMUM 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. All other pins ............................................................-0.3V to V +0.3V CC V .................................................................................................. 7V CC V .................................................................................................. 22V IN Storage Temperature ................................................... -65C to 150C I .................................................................................................... 5A LX Power Dissipation ..................................................... Internally Limited BST ................................................................................................ 35V ESD Rating ........................................................................... 2kV HBM LX-BST ...............................................................................-0.3V to 7V LX ........................................................................................- V to 20V Thermal Resistance ........................................................... 5C/W JC ELECTRICAL CHARACTERISTICS Unless otherwise specified: -40C < T < 85C, -40C< Tj <125C, 4.5V < V < 5.5V, 3V< Vin < 20V, BST=LX + 5V, AMB CC LX = GND = 0.0V, UVIN = 3.0V, CV = F, C = 0.F , C = 50nF, Typical measured at V = 5V. CC COMP SS CC The denotes the specifications which apply over the full temperature range, unless otherwise specified. PARAMETER MIN. TYP. MAX. UNITS CONDITIONS QUIESCENT CURRENT Vcc Supply Current (No switching) .5 3 mA Vfb =0.9V Vcc Supply Current (switching) 8 2 mA BST Supply Current (No switching) 0.2 0.4 mA Vfb =0.9V BST Supply Current (switching) 4 6 mA PROTECTION: UVLO Vcc UVLO Start Threshold 4.00 4.25 4.5 V Vcc UVLO Hysteresis 00 200 300 mV UVIN Start Threshold 2.3 2.5 2.65 V UVIN Hysteresis 200 300 400 mV UVIN Input Current A UVIN= 3.0V ERROR AMPLIFIER REFERENCE 2X Gain Config., Measure Error Amplifier Reference 0.792 0.800 0.808 V Vfb Vcc =5 V, T=25C Error Amplifier Reference Over Line and Temperature 0.788 0.800 0.8 2 V Error Amplifier Transconductance 6 mA/V Error Amplifier Gain 60 dB No Load COMP Sink Current 50 A Vfb =0.9V, COMP= 0.9V COMP Source Current 50 A Vfb =0.7V, COMP= 2.2V Vfb Input Bias Current 50 200 nA Vfb = 0.8V Internal Pole 4 MHz COMP Clamp 2.5 V Vfb =0.7V, TA=25C COMP Clamp Temp. Coefficient -2 mV/C Rev J: 3/4/07 SP765 Wide Input Voltage Range 3A, 900kHz, Buck Regulator Copyright 2007 Sipex Corporation 2