MAX1715EEI+TG035

19-1541; Rev 2; 8/05 KIT ATION EVALU LE B A IL A AV Ultra-High Efficiency, Dual Step-Down Controller for Notebook Computers Features The MAX1715 PWM controller provides the high efficiency, excellent transient response, and high DC output accuracy needed for stepping down high-voltage batteries to generate low-voltage CPU core, I/O, and chipset RAM supplies in notebook computers. Maxim’s proprietary Quick-PWM™ quick-response, constant-on-time PWM control scheme handles wide input/output voltage ratios with ease and provides 100ns “instant-on” response to load transients while maintaining a relatively constant switching frequency. ♦ Ultra-High Efficiency The MAX1715 achieves high efficiency at a reduced cost by eliminating the current-sense resistor found in traditional current-mode PWMs. Efficiency is further enhanced by its ability to drive very large synchronousrectifier MOSFETs. Single-stage buck conversion allows this device to directly step down high-voltage batteries for the highest possible efficiency. Alternatively, two-stage conversion (stepping down the +5V system supply instead of the battery) at a higher switching frequency allows the minimum possible physical size. ♦ 200/300/420/540kHz Nominal Switching Frequency The MAX1715 is intended for CPU core, chipset, DRAM, or other low-voltage supplies as low as 1V. The MAX1715 is available in a 28-pin QSOP package. For applications requiring VID compliance or DAC control of output voltage, refer to the MAX1710/MAX1711 data sheet. For a single-output version, refer to the MAX1714 data sheet. ♦ No Current-Sense Resistor (lossless ILIMIT) ♦ Quick-PWM with 100ns Load-Step Response ♦ 1% VOUT Accuracy over Line and Load ♦ Dual-Mode Fixed 1.8V/3.3V/Adj or 2.5V/Adj Outputs ♦ Adjustable 1V to 5.5V Output Range ♦ 2V to 28V Battery Input Range ♦ Over/Undervoltage Protection ♦ 1.7ms Digital Soft-Start ♦ Drives Large Synchronous-Rectifier FETs ♦ Power-Good Indicator Ordering Information TEMP RANGE PIN-PACKAGE MAX1715EEI PART -40°C to +85°C 28 QSOP MAX1715EEI+ -40°C to +85°C 28 QSOP + Denotes lead-free package. Minimal Operating Circuit Applications Notebook Computers CPU Core Supply 5V INPUT Chipset/RAM Supply as Low as 1V V+ VCC 1.8V and 2.5V I/O Supply MAX1715 ILIM1 ILIM2 ON1 ON2 OUTPUT1 1.8V Pin Configuration appears at end of data sheet. BATTERY 4.5V TO 28V VDD BST1 BST2 DH1 DH2 LX1 LX2 DL1 DL2 TON PGND OUTPUT2 2.5V OUT1 OUT2 PGOOD SKIP REF FB1 AGND FB2 Quick-PWM is a trademark of Maxim Integrated Products. ________________________________________________________________ Maxim Integrated Products 1 For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. MAX1715 General Description MAX1715 Ultra-High Efficiency, Dual Step-Down Controller for Notebook Computers ABSOLUTE MAXIMUM RATINGS V+ to AGND..............................................................-0.3 to +30V VDD , VCC to AGND ..................................................-0.3V to +6V PGND to AGND or VCC to VDD ...........................................±0.3V PGOOD, OUT_ to AGND..........................................-0.3V to +6V ILIM_, FB_, REF, SKIP, TON, ON_ to AGND ...........................................-0.3V to (VDD + 0.3V) DL_ to PGND ..............................................-0.3V to (VDD + 0.3V) BST_ to AGND........................................................-0.3V to +36V DH1 to LX1 ...............................................-0.3V to (BST1 + 0.3V) DH2 to LX2 ...............................................-0.3V to (BST2 + 0.3V) LX1 to BST1..............................................................-6V to +0.3V LX2 to BST2..............................................................-6V to +0.3V REF Short Circuit to AGND.........................................Continuous Continuous Power Dissipation (TA = +70°C) 28-Pin QSOP (derate 8.0mW/°C above +70°C).....640mW/°C Operating Temperature Range ..........................-40°C to +85°C Junction Temperature ......................................................+150°C Storage Temperature Range ............................-65°C to +150°C Lead Temperature (soldering, 10s) .................................+300°C 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, 4A components from Table 1, VCC = VDD = +5V, SKIP = AGND, V+ = 15V, TA = 0°C to +85°C, unless otherwise noted.) (Note 1) PARAMETER Input Voltage Range MIN Battery voltage, V+ VDD, VCC TYP MAX 2 28 4.5 5.5 Output 1 Error Comparator Threshold (DC Output Voltage Accuracy) (Note 2) V+ = 2V to 28V, SKIP = VCC, TA = +25°C ILOAD = 0 to 4A FB1 = OUT1 0.99 1.00 1.01 FB1 = AGND 1.782 1.8 1.818 FB1 = VCC 3.267 3.3 3.333 Output 1 Error Comparator Threshold (DC Output Voltage Accuracy) (Note 2) V+ = 2V to 28V, SKIP = VCC, TA = 0°C to +85°C ILOAD = 0 to 4A FB1 = OUT1 0.985 1.00 1.105 FB1 = AGND 1.773 1.8 1.827 FB1 = VCC 3.250 3.3 3.350 Output 2 Error Comparator Threshold (DC Output Voltage Accuracy) (Note 2) V+ = 2V to 28V, SKIP = VCC, TA = +25°C ILOAD = 0 to 4A FB2 = OUT2 0.99 1.00 1.01 FB2 = GND 2.475 2.5 2.525 Output 2 Error Comparator Threshold (DC Output Voltage Accuracy) (Note 2) V+ = 2V to 28V, SKIP = VCC, TA = 0°C to +85°C ILOAD = 0 to 4A FB2 = OUT2 0.985 1.00 1.105 FB2 = GND 2.463 2.5 2.538 Load Regulation Error ILOAD = 0 to 4A, each output 0.4 Line Regulation Error VCC = 4.5V to 5.5V, V+ = 4.5V to 28V 0.2 Output Voltage Range Adjustable mode, each output OUT_ Input Resistance FB_ = AGND 75k FB_ Input Bias Current VOUT_ = AGND -0.1 Soft-Start Ramp Time Rising edge of ON_ to full current limit On-Time (PWM1) On-Time (PWM2) 2 CONDITIONS V+ = 24V, OUT1 = 2V V+ = 24V, OUT2 = 2V UNITS V V V V V 1 % % 5.5 V 0.1 µA Ω 1.7 ms TON = GND 112 136 160 TON = REF 142 173 205 TON = open 210 247 280 TON = VDD 300 353 407 TON = GND 154 182 215 TON = REF 198 234 270 TON = open 292 336 380 TON = VDD 420 484 550 _______________________________________________________________________________________ ns ns Ultra-High Efficiency, Dual Step-Down Controller for Notebook Computers (Circuit of Figure 1, 4A components from Table 1, VCC = VDD = +5V, SKIP = AGND, V+ = 15V, TA = 0°C to +85°C, unless otherwise noted.) (Note 1) PARAMETER Minimum Off-Time CONDITIONS MIN (Note 3) Quiescent Battery Current (V+) TYP MAX UNITS 400 500 ns 25 70 µA 1100 1600 µA Quiescent Supply Current (VCC + VDD) FB1 and FB2 forced above the regulation point Shutdown Supply Current (VCC + VDD) ON1 = ON2 = 0