MAX1960/MAX1961/MAX1962 19-2740 Rev 1 6/09 2.35V to 5.5V, 0.5% Accurate, 1MHz PWM Step-Down Controllers with Voltage Margining General Description Features The MAX1960/MAX1961/MAX1962 high-current, high- 0.5% Accurate Output efficiency voltage-mode step-down DC-DC controllers Operates from 2.35V to 5.5V Supply operate from a 2.35V to 5.5V input and generate output Generates Low Output Voltage Down to 0.8V voltages down to 0.8V at up to 20A. An on-chip charge pump generates a regulated 5V for MOSFET drive. On-Chip Charge Pump Provides 5V Gate Drive Additionally, adaptive dead-time drivers allow a Ceramic or Electrolytic Capacitors wide variety of MOSFETs to be used without risking 94% Efficiency shoot-through. External Synchronization from 450kHz to 1.2MHz Fixed-frequency PWM operation and external synchro- nization make these controllers suitable for telecom 500kHz/1MHz Fixed-Frequency PWM Operation and datacom applications. The operating frequency is Fast Transient Response programmable to either 500kHz or 1MHz, or from Two Converters Can Operate 180 Out-of-Phase 450kHz to 1.2MHz with an external clock. A clock output is provided to synchronize another converter for 180 4% Voltage Margining for System Test out-of-phase operation. A high closed-loop bandwidth 10% Accurate Current Sensing (MAX1962) provides excellent transient response for applications Adaptive Dead Time Prevents Shoot-Through with dynamic loads. Lossless current sensing in the MAX1960 and Ordering Information MAX1961 is achieved by monitoring the drain-to-source voltage of the low-side external FET. The current limit is PART TEMP RANGE PIN-PACKAGE scalable to accommodate a wide variety of MOSFETs MAX1960EEP -40C to +85C 20 QSOP and load currents. The MAX1962 has 10% accurate MAX1961EEP -40C to +85C 20 QSOP sense-resistor-based current limiting. MAX1962EEP -40C to +85C 20 QSOP The MAX1960 and MAX1962 have an adjustable output voltage from 0.8V to 4.95V. The MAX1961 and MAX1962 have four preset output voltages (1.5V, 1.8V, Typical Operating Circuit 2.5V, and 3.3V) and feature 0.5% voltage accuracy over temperature, line, and load variations. The MAX1960 and MAX1961 also feature voltage-margining control inputs that shift the output voltage up or down C+ C- INPUT by 4% for system testing. 2.35V TO 5.5V AV V DD CC MAX1960 VDD CTL1 VOLTAGE MARGINING BST Applications AND ON/OFF CTL2 DH COMP ASIC, FPGA, DSP, and CPU Core and I/O Voltages OUTPUT 0.8 TO 0.87 V IN UP TO 20A Cellular Base Stations REF LX Telecom and Network Equipment DL Server and Storage Systems GND PGND ILIM FSET/SYNC OPTIONAL SYNCHRONIZATION CLKOUT Pin Configurations and Selector Guide appear at the end 180 OUT-OF-PHASE FB CLKOUT of the data sheet. 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 AVAILABLE2.35V to 5.5V, 0.5% Accurate, 1MHz PWM Step-Down Controllers with Voltage Margining ABSOLUTE MAXIMUM RATINGS V , CTL , CS, FSET/SYNC, SEL, EN, Continuous Power Dissipation (T = +70C) CC A OUT to GND ..........................................................-0.3V to +6V 20-Pin QSOP (derate up to +70C)..............................727mW ILIM, COMP, REF, FB, CLKOUT, 20-Pin QSOP (derate above +70C)........................9.1mW/C C- to GND ..............................................-0.3V to V + 0.3V Operating Temperature Range (Extended).........-40C to +85C AVDD C+ to GND.............-0.3V to higher of V + 1V or V + 0.3V Junction Temperature......................................................+150C VCC VDD V , AV to GND..............-0.3V to higher of V - 0.3V or 6V Storage Temperature Range .............................-65C to +150C DD DD VCC DL to PGND ................................................-0.3V to V + 0.3V Lead Temperature (soldering, 10s) .................................+300C VDD BST to GND............................................................-0.3V to +12V DH to LX ...................................................................-0.3V to +6V LX to BST..................................................................-6V to +0.3V PGND to GND, or V to AV ............................-0.3V to +0.3V DD DD 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 (V = 3.3V, Circuits of Figures 912, T = 0C to +85C. Typical values are at T = +25C, unless otherwise noted.) VCC A A PARAMETER CONDITIONS MIN TYP MAX UNITS V Input Voltage Range 2.35 5.5 V CC V Input Voltage UVLO Rising or falling, hysteresis = 33mV (typ) 1.95 2.3 V CC V Input Voltage UVLO Rising or falling, hysteresis = 44mV (typ) 3.9 4.45 V DD Output Voltage 0.8 V MAX1960/MAX1962 (measured at FB) 0.796 0.800 0.804 SEL = GND 1.492 1.500 1.508 MAX1961/ DC Output Accuracy SEL = REF 1.791 1.800 1.809 V MAX1962 (FB = V ), DD SEL not connected 2.487 2.500 2.514 measured at output SEL = V 3.272 3.300 3.336 DD Positive Voltage-Margining Shift MAX1960/MAX1961 +3.8 +4 +4.2 % Negative Voltage-Margining Shift MAX1960/MAX1961 -3.8 -4 -4.2 % Load Regulation Error 0V to full load 0.08 % Line Regulation Error V = 2.7V to 5.5V 0.1 % VCC FB Input Bias Current -0.2 +0.2 A Feedback Transconductance 1 2 3 mS COMP Discharge Resistance In shutdown 10 100 DC-DC Soft-Start Time 1280 cycles FSET/SYNC = GND 450 500 550 Switching Frequency kHz FSET/SYNC = V 880 1000 1120 CC SYNC Frequency Range 450 1200 kHz Maximum Duty Cycle f = 1MHz 80 83 % Maximum Duty Cycle f = 500kHz 90 92 % Quiescent Supply Current 11 15 mA Shutdown Supply Current 15 A 2 MAX1960/MAX1961/MAX1962