MAX1710/MAX1711/MAX1712 19-4781 Rev 1 7/00 High-Speed, Digitally Adjusted Step-Down Controllers for Notebook CPUs General Description Features The MAX1710/MAX1711 step-down controllers are Ultra-High Efficiency intended for core CPU DC-DC converters in notebook No Current-Sense Resistor (Lossless I ) LIMIT computers. They feature a triple-threat combination of ultra-fast transient response, high DC accuracy, and Quick-PWM with 100ns Load-Step Response high efficiency needed for leading-edge CPU core 1% V Accuracy over Line and Load OUT power supplies. Maxims proprietary Quick-PWM 4-Bit On-Board DAC (MAX1710) quick-response, constant-on-time PWM control scheme handles wide input/output voltage ratios with ease and 5-Bit On-Board DAC (MAX1711/MAX1712) provides 100ns instant-on response to load transients 0.925V to 2V Output Adjust Range while maintaining a relatively constant switching fre- (MAX1711/MAX1712) quency. High DC precision is ensured by a 2-wire remote-sens- 2V to 28V Battery Input Range ing scheme that compensates for voltage drops in both 200/300/400/550kHz Switching Frequency the ground bus and supply rail. An on-board, digital-to- Remote GND and V Sensing analog converter (DAC) sets the output voltage in com- OUT pliance with Mobile Pentium II CPU specifications. Over/Undervoltage Protection The MAX1710 achieves high efficiency at a reduced 1.7ms Digital Soft-Start cost by eliminating the current-sense resistor found in Drive Large Synchronous-Rectifier FETs traditional current-mode PWMs. Efficiency is further enhanced by an ability to drive very large synchronous- 2V 1% Reference Output rectifier MOSFETs. Power-Good Indicator Single-stage buck conversion allows these devices to Small 24-Pin QSOP Package directly step down high-voltage batteries for the highest possible efficiency. Alternatively, 2-stage conversion Ordering Information (stepping down the +5V system supply instead of the battery) at a higher switching frequency allows the mini- PART TEMP. RANGE PIN-PACKAGE mum possible physical size. MAX1710EEG -40C to +85C 24 QSOP The MAX1710/MAX1711 are identical except that the MAX1711EEG -40C to +85C 24 QSOP MAX1711 have 5-bit DACs and the MAX1710 has a 4- bit DAC. Also, the MAX1711 has a fixed overvoltage protection threshold at V = 2.25V and undervoltage OUT Minimal Operating Circuit protection at V = 0.8V whereas the MAX1710 has OUT variable thresholds that track V . The MAX1711 is OUT BATTERY 4.5V TO 28V intended for applications where the DAC code may +5V INPUT change dynamically. V OVP* V CC DD Applications V+ SHDN FBS Notebook Computers BST ILIM Docking Stations DH GNDS OUTPUT 0.925V TO 2V CPU Core DC-DC Converters (MAX1711/MAX1712) MAX1710 Single-Stage (BATT to V Converters CORE) MAX1711 REF LX MAX1712 Two-Stage (+5V to V ) Converters CORE CC DL D0 PGND D1 D/A Quick-PWM is a trademark of Maxim Integrated Products. D2 INPUTS FB D3 Mobile Pentium II is a registered trademark of Intel Corp. SKIP D4** GND Pin Configurations appear at end of data sheet. *MAX1710 ONLY **MAX1711/MAX1712 ONLY Maxim Integrated Products 1 For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642, or visit Maxims website at www.maxim-ic.com. EVALUATION KIT AVAILABLEHigh-Speed, Digitally Adjusted Step-Down Controllers for Notebook CPUs ABSOLUTE MAXIMUM RATINGS V+ to GND..............................................................-0.3V to +30V DH to LX .....................................................-0.3V to (BST + 0.3V) V , V to GND .....................................................-0.3V to +6V LX to BST..................................................................-6V to +0.3V CC DD PGND to GND.....................................................................0.3V REF Short Circuit to GND...........................................Continuous SHDN, PGOOD to GND ...........................................-0.3V to +6V Continuous Power Dissipation (T = +70C) A OVP, ILIM, FB, FBS, CC, REF, D0D4, 24-Pin QSOP (derate 9.5mW/C above +70C)..........762mW GNDS, TON to GND..............................-0.3V to (V + 0.3V) Operating Temperature Range ...........................-40C to +85C CC SKIP to GND (Note 1).................................-0.3V to (V + 0.3V) Junction Temperature......................................................+150C CC DL to PGND................................................-0.3V to (V + 0.3V) Storage Temperature Range .............................-65C to +165C DD BST to GND............................................................-0.3V to +36V Lead Temperature (soldering, 10s) .................................+300C Note 1: SKIP may be forced below -0.3V, temporarily exceeding the absolute maximum rating, for the purpose of debugging proto- type breadboards using the no-fault test mode. Limit the current drawn to -5mA maximum. 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, V = 15V, V = V = 5V, SKIP = GND, T = 0C to +85C, unless otherwise noted.) BATT CC DD A PARAMETER CONDITIONS MIN TYP MAX UNIT Battery voltage, V+ 228 Input Voltage Range V V V 4.5 5.5 CC, DD DAC codes from 1.3V to 2V -1 1 V = 4.5V to 28V, includes BATT DC Output Voltage Accuracy % DAC codes from 0.925V load regulation error -1.2 1.2 to 1.275V Load Regulation Error I = 0 to 7A 9 mV LOAD Remote-Sense Voltage Error FB - FBS or GNDS - GND = 0 to 25mV 3 mV Line Regulation Error V = 4.5V to 5.5V, V = 4.5V to 28V 5 mV CC BATT FB Input Bias Current FB (MAX1710 only) or FBS -0.2 0.2 A FB Input Resistance 130 180 240 k (MAX1711/MAX1712) GNDS Input Bias Current -1 1 A Soft-Start Ramp Time Rising edge of SHDN to full I 1.7 ms LIM TON = GND (550kHz) 140 160 180 V = 24V, BATT TON = REF (400kHz) 175 200 225 On-Time FB = 2V ns TON = open (300kHz) 260 290 320 (Note 2) TON = V (200kHz) 380 425 470 CC Minimum Off-Time (Note 2) 400 500 ns Quiescent Supply Current (V ) Measured at V , FB forced above the regulation point 600 950 A CC CC Quiescent Supply Current (V ) Measured at V , FB forced above the regulation point <1 5 A DD DD Quiescent Battery Supply Current Measured at V+ 25 40 A Shutdown Supply Current (V ) SHDN = 0 <1 5 A CC Shutdown Supply Current (V ) <1 5 A DD SHDN = 0 Shutdown Battery Supply SHDN = 0, measured at V+ = 28V, V = V = 0 or 5V <1 5 A CC DD Current Reference Voltage V = 4.5V to 5.5V, no external REF load 1.98 2 2.02 V CC Reference Load Regulation I = 0 to 50A 0.01 V REF REF Sink Current REF in regulation 10 A REF Fault Lockout Voltage Falling edge, hysteresis = 40mV 1.6 V 2 MAX1710/MAX1711/MAX1712