MAX17020 19-4118 Rev 2 2/09 Dual Quick-PWM Step-Down Controller with Low-Power LDO, RTC Regulator General Description Features The MAX17020 is a dual Quick-PWM step-down Dual Quick-PWM power-supply (SMPS) controller with synchronous rec- Internal 100mA 5V or Adjustable Linear Regulator tification, intended for main 5V/3.3V or I/O 1.5V/1.05V Independent LDO Bypass Input power generation in battery-powered systems. Low- Internal Boost Diodes side MOSFET sensing provides a simple low-cost, highly efficient current sense for valley current-limit Secondary Feedback Input Maintains Charge Pump protection. Combined with the output overvoltage and 3.3V 5mA RTC Power (Always On) undervoltage protection features, this current limit OUT1: 5V or 1.5V Fixed or 0.7V Adjustable ensures robust output supplies. Feedback The 5V/3.3V or 1.5V/1.05V SMPS outputs can save OUT2: 3.3V or 1.05V Fixed or Dynamic Adjustable power by operating in pulse-skipping mode or in ultra- sonic mode to avoid audible noise. Ultrasonic mode Dynamic 0V to 2V REFIN2 Input on Second SMPS forces the controller to maintain switching frequencies 2V 1% 50A Reference greater than 20kHz at light loads. 6V to 24V Input Range (28V max) An internal 100mA linear regulator can be used to Ultrasonic Mode either generate the 5V bias needed for power-up or other lower power always-on suspend supplies. An Independent SMPS and LDO Enable Controls independent bypass input allows automatic bypassing Independent SMPS Power-Good Outputs of the linear regulator when the SMPS is active. Minimal Component Count This main controller also includes a secondary feed- back input that triggers an ultrasonic pulse (DL1 turned Ordering Information on) if the SECFB voltage drops below its threshold volt- age. This refreshes an external charge pump driven by PART TEMP RANGE PIN-PACKAGE DL1 without overcharging the output voltage. M AX 17020ETJ + -40C to +85C 32 TQFN The device includes independent shutdown controls to +Denotes a lead(Pb)-free/RoHS-compliant package. simplify power-up and power-down sequencing. To *EP = Exposed pad. prevent current surges at startup, the internal voltage target is slowly ramped up from zero to the final target Pin Configuration over a 1ms period. To prevent the output from ringing below ground in shutdown, the internal voltage target is ramped down from its previous value to zero over a TOP VIEW 1ms period. Two independent power-good outputs 24 23 22 21 20 19 18 17 simplify the interface with external controllers. LX2 25 16 LX1 The MAX17020 is a pin-for-pin replacement of the DH1 DH2 26 15 MAX8778. 27 14 ON1 ON2 Applications 28 13 PGOOD1 PGOOD2 Notebook Computers MAX17020 29 12 SKIP ILIM1 Main System Supply (5V and 3.3V Supplies) FB1 OUT2 30 11 I/O System Supply (1.5V and 1.05V Supplies) ILIM2 31 10 OUT1 Graphic Cards REFIN2 32 + 9 BYP 12 3 45 6 7 8 DDR1, DDR2, DDR3 Power Supplies Game Consoles Low-Power I/O and Chipset Supplies THIN QFN (T3255-4) Two-to-Four Li+ Cell Battery-Powered Devices 5mm x 5mm A SIGN FIRST-PIN INDICATOR DENOTES A LEAD-FREE PACKAGE. PDAs and Mobile Communicators Telecommunication Quick-PWM is a trademark of Maxim Integrated Products, Inc. Maxim Integrated Products 1 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com. EVALUATION KIT AVAILABLE REF BST2 TON DL2 V CC PGND ONLDO AGND RTC SECFB IN V DD DL1 LDO BST1 LDOREFINDual Quick-PWM Step-Down Controller with Low-Power LDO, RTC Regulator ABSOLUTE MAXIMUM RATINGS IN, ONLDO to GND ................................................-0.3V to +28V BST1 to LX1..............................................................-0.3V to +6V V , V to GND .....................................................-0.3V to +6V DH2 to LX2 ..............................................-0.3V to (V + 0.3V) DD CC BST2 RTC, LDO to GND ....................................................-0.3V to +6V BST2 to LX2..............................................................-0.3V to +6V OUT to GND ...........................................................-0.3V to +6V LDO, RTC, REF Short Circuit to GND.........................Momentary ON1, ON2 to GND....................................................-0.3V to +6V RTC Current Continuous.....................................................+5mA PGOOD to GND........................................-0.3V to (V + 0.3V) LDO Current (Internal Regulator) CC REF, ILIM , TON, SKIP to GND..................-0.3V to (V + 0.3V) Continuous..................................................................+100mA CC FB1, REFIN2, LDOREFIN to GND ............................-0.3V to +6V LDO Current (Switched Over) Continuous .....................+200mA SECFB to GND .........................................................-0.3V to +6V Continuous Power Dissipation (T = +70C) A BYP to GND..............................................-0.3V to (V + 0.3V) 32-Pin 5mm x 5mm TQFN LDO GND to PGND .......................................................-0.3V to +0.3V (derate 34.5mW/C above +70C).................................2.76W DL to PGND..............................................-0.3V to (V + 0.3V) Operating Temperature Range ...........................-40C to +85C DD BST to GND ..........................................................-0.3V to +34V Junction Temperature......................................................+150C BST to V ............................................................-0.3V to +28V Storage Temperature Range .............................-65C to +150C DD DH1 to LX1 ..............................................-0.3V to (V + 0.3V) Lead Temperature (soldering, 10s) .................................+300C BST1 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. ELECTRICAL CHARACTERISTICS (Circuit of Figure 1, no load on LDO, RTC, OUT1, OUT2, and REF, V = 12V, V = V = V = 5V, V = 1.0V, BYP = IN DD CC SECFB REFIN2 LDOREFIN = GND, ONLDO = IN, ON1 = ON2 = V , T = 0C to +85C, unless otherwise noted. Typical values are at T = +25C.) CC A A (Note 3) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS INPUT SUPPLIES V = 6V to 24V, ON1 = ON2 = GND, IN IN Standby Supply Current I 85 175 A IN(STBY) ONLDO = V CC V = 4.5V to 24V, IN IN Shutdown Supply Current I 50 70 A IN(SHDN) ON1 = ON2 = ONLDO = GND ON1 = ON2 = REFIN2 = V , CC IN Supply Current I 0.1 0.2 mA IN SKIP = FB1 = GND, V = 3.5V, V = 5.3V OUT2 OUT1 ON1 = ON2 = REFIN2 = V , CC V Supply Current I 1.0 1.5 mA CC CC SKIP = FB1 = GND, V = 3.5V, V = 5.3V OUT2 OUT1 PWM CONTROLLERS 5V preset output: FB1 = GND, 4.95 5.00 5.05 V = 12V, SKIP = V IN CC V OUT1 OUT1 Output Voltage Accuracy 1.5V preset output: FB1 = V (5V), CC V 1.485 1.50 1.515 (Note 1) V = 12V, SKIP = V IN CC Adjustable feedback output, V 0.693 0.700 0.707 FB1 V = 12V, SKIP = V IN CC OUT1 Voltage Adjust Range 0.7 5.5 V Low 0.04 0.110 FB1 Dual-Mode Threshold V V - V - CC CC Voltage Levels High 1.6V 0.7V FB1 Input Bias Current I V = 0.8V, T = +25C -0.2 +0.2 A FB1 FB1 A Dual Mode is a trademark of Maxim Integrated Products, Inc. 2 MAX17020