SSPP66113377 Wide Input, 900kHz Synchronous PWM Step Down Wide Input, 900kHz Synchronous PWM Step Down CCoonnttrroolllleerr January 2009 Rev. 2.0.0 GENERAL DESCRIPTION APPLICATIONS The SP6137 is a 900kHz constant frequency, 12V DPA voltage mode, synchronous PWM step down Communications Systems controller optimized for high efficiency. Graphics Cards The SP6137 is adequately suited for split plane applications utilizing a low power 5V rail to power the controller circuitry, minimizing FEATURES power dissipation. Its wide input voltage range 2.5V to 20V Step Down Achieved Using of 3V to 15V allows for conversions from the Dual Input standard 3.3V, 5V, 9.6V and 12V power rails to an output voltage adjustable down to 0.8V. On-Board 1.5 sink (2 source) NFET Developed around a wide bandwidth internal Drivers amplifier, the SP6137 can accommodate type Up to 10A Output Capability II and type III compensation schemes. UVLO Detects Both VCC and VIN Protection features include a programmable UVLO, thermal shutdown and output short Short-Circuit Protection with Auto- circuit protection. Restart The SP6137 is part of a larger family of step Supports Type II or III Compensation down controllers operating at various Programmable Soft Start switching frequencies up to 1300kHz and input voltages up to 28V. Refer to Exars SP6132, Fast Transient Response SP6132H, SP6134, SP6134H and SP6139 for High Efficiency: Greater than 94% complete details. Non-synchronous Start-Up The SP6137 is available in lead free, RoHS compliant, space saving 10-pin MSOP Small 10-Pin MSOP Package package. U.S. Patent 6,922,041 TYPICAL APPLICATION DIAGRAM V IN 2.5V -20V C1 C2 22F 22F 8 7 6 5 16V 16V V = 5V 30mA CC FDS6676S QT GND 14.5A, 6m 4 C1, C2 RLF 1 2 3 Ceramic 3.0,5% 1210 X5R CBST 0.1F U1 DBST V V OUT IN MBR0530 R5 L1 SC5018-2R7M 3.3V 10A RZ3 1 10 Bead 8 7 6 5 2.7H 12A VCC BST 4.64k, 1% SP6137 DCR=4.30m 2 C 9 VCC GND 3 GL GH C3 C4 QB R1 10F 47F 47F 3 8 GND SWN 68.1k, 1% 6.3V 4 6.3V CZ3 R3 6.3V 4 7 221k, 1% VFB SS SS 220pF 0.8V 1 2 3 5 6 COMP UVIN FDS6676S C 14.5A, 6.0m UV VCC IN CSS GND2 Ceramic CZ2 RZ2 47nF 8050 R2 820pF 40.2k, 1% R4 21.5k, 1% X5R C3, C4 100k, 1% CP1 Ceramic 1210 CF1 56pF X5R 100pF Fig. 1: SP6137 Application Diagram Exar Corporation www.exar.com 48720 Kato Road, Fremont CA 94538, USA Tel. +1 510 668-7000 Fax. +1 510 668-7001 SSPP66113377 Wide Input, 900kHz Synchronous PWM Step Down Wide Input, 900kHz Synchronous PWM Step Down CCoonnttrroolllleerr ABSOLUTE MAXIMUM RATINGS These are stress ratings only and functional operation of GH, GL peak output current <10us..............................2A the device at these ratings or any other above those Storage Temperature ..............................-65C to 150C indicated in the operation sections of the specifications Power Dissipation.................................Internally Limited below is not implied. Exposure to absolute maximum ESD Rating BST Pin (HBM - Human Body Model)...... 1.5kV rating conditions for extended periods of time may affect ESD Rating All Other Pins (HBM)...............................2kV reliability. Thermal Resistance ....................................41.9C/W JA V .......................................................................... 7V cc Operating Voltage Range ..............................2.5V to 20V BST ...................................................................... 27V BST-SWN ......................................................-0.3 to 7V SWN ............................................................-1V to 20V GH................................................... -0.3V to BST+0.3V GH-SWN.................................................................. 7V All other pins ..................................... -0.3V to V +0.3V CC ELECTRICAL SPECIFICATIONS Specifications with standard type are for an Operating Junction Temperature of T = 25C only limits applying over the full J 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 T = 25C, and are provided for J reference purposes only. Unless otherwise indicated, V = 4.5V to 5.5V, BST= V , SWN=GND=0V, UVIN=3V, CV = 10F, cc cc cc C =0.1uF, CGH=CGL=3.3nF, C =50nF, T = 40C to 85C (SP6137EU) or T = 0C to 70C (SP6137CU).. COMP SS A A Parameter Min. Typ. Max. Units Conditions V Supply Current 1.5 3 mA VFB =0.9V (No switching) CC BST Supply Current 0.2 0.4 mA VFB =0.9V (No switching) V UVLO Start Threshold 4.00 4.25 4.50 V CC V UVLO Hysteresis 100 200 300 mV CC UVIN Start Threshold 2.30 2.50 2.65 V UVIN Hysteresis 260 300 390 mV UVIN Input Current 1 uA UVIN=3.0V 2X Gain Config., Measure VFB, V =5V, CC Error Amplifier Reference 0.792 0.800 0.808 V T=25C Error Amplifier Reference 0.788 0.800 0.812 V Over Line and Temperature Error Amplifier 6 mS Transconductance Error Amplifier Gain 60 dB No Load COMP Sink Current 150 uA VFB=0.9V, COMP=0.9V COMP Source Current 150 uA 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 Ramp Amplitude 0.92 1.10 1.28 V TA = 25C, RAMP COMP until GH starts RAMP Offset 1.1 V switching RAMP Offset Temp. Coefficient -2 mV/C GH Minimum Pulse Width 90 180 ns Maximum Controllable Duty Maximum Duty Ratio Measured just 92 97 % Ratio before pulse skipping begins Maximum Duty Ratio 100 % Valid for 20 Cycles Internal Oscillator Frequency 760 900 1040 kHz SS Charge Current: 10 uA 2008 Exar Corporation 2/15 Rev. 2.0.0