MAX15038 19-4320 Rev 3 12/10 4A, 2MHz Step-Down Regulator with Integrated Switches General Description Features Internal 31m R High-Side and 24m The MAX15038 high-efficiency switching regulator DS(ON) R Low-Side MOSFETs delivers up to 4A load current at output voltages from DS(ON) 0.6V to 90% of V . The IC operates from 2.9V to 5.5V, Continuous 4A Output Current Over Temperature IN making it ideal for on-board point-of-load and postregu- 1% Output Accuracy Over Load, Line, and lation applications. Total output error is less than 1% Temperature over load, line, and temperature ranges. Operates from 2.9V to 5.5V V Supply IN Adjustable Output from 0.6V to (0.9 x V ) IN The MAX15038 features fixed-frequency PWM mode Soft-Start Reduces Inrush Supply Current operation with a switching frequency range of 500kHz 500kHz to 2MHz Adjustable Switching Frequency to 2MHz set by an external resistor. The MAX15038 provides the option of operating in a skip mode to Compatible with Ceramic, Polymer, and improve light-load efficiency. High-frequency operation Electrolytic Output Capacitors allows for an all-ceramic capacitor design. The high Nine Preset and Adjustable Output Voltages operating frequency also allows for small-size external 0.6V, 0.7V, 0.8V, 1.0V, 1.2V, 1.5V, 1.8V, 2.0V, 2.5V, and Adjustable components. Monotonic Startup for Safe-Start into Prebiased The low-resistance on-chip nMOS switches ensure high Outputs efficiency at heavy loads while minimizing critical induc- Selectable Forced PWM or Skip Mode for Light tances, making the layout a much simpler task with Load Efficiency respect to discrete solutions. Following a simple layout Overcurrent and Overtemperature Protection and footprint ensures first-pass success in new designs. Output Current Sink/Source Capable with Cycle- The MAX15038 comes with a high bandwidth (28MHz) by-Cycle Protection voltage-error amplifier. The voltage-mode control archi- Open-Drain Power-Good Output tecture and the voltage-error amplifier permit a type III Lead-Free, 4mm x 4mm, 24-Pin Thin QFN Package compensation scheme to be utilized to achieve maxi- mum loop bandwidth, up to 20% of the switching fre- Ordering Information quency. High loop bandwidth provides fast transient PART TEMP RANGE PIN-PACKAGE response, resulting in less required output capacitance and allowing for all-ceramic-capacitor designs. MAX15038ETG+ -40C to +85C 24 Thin QFN-EP* The MAX15038 provides two three-state logic inputs to +Denotes a lead(Pb)-free/RoHS-compliant package. select one of nine preset output voltages. The preset *EP = Exposed pad. output voltages allow customers to achieve 1% out- Typical Operating Circuit put-voltage accuracy without using expensive 0.1% resistors. In addition, the output voltage can be set to INPUT any customer value by either using two external resis- 2.9V TO 5.5V IN BST tors at the feedback with a 0.6V internal reference or applying an external reference voltage to the REFIN OUTPUT MAX15038 EN 1.8V, 4A input. The MAX15038 offers programmable soft-start LX time using one capacitor to reduce input inrush current. V DD OUT Applications PGND Server Power Supplies CTL2 POLs FB CTL1 ASIC/CPU/DSP Core and I/O Voltages FREQ DDR Power Supplies REFIN Base-Station Power Supplies V SS DD COMP Telecom and Networking Power Supplies RAID Control Power Supplies MODE PWRGD GND Pin Configuration appears at end of 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 AVAILABLE4A, 2MHz Step-Down Regulator with Integrated Switches ABSOLUTE MAXIMUM RATINGS IN, PWRGD to GND..................................................-0.3V to +6V V Output Short-Circuit Duration .............................Continuous DD V to GND..................-0.3V to the lower of +4V or (V + 0.3V) Converter Output Short-Circuit Duration....................Continuous DD IN COMP, FB, MODE, REFIN, CTL1, CTL2, SS, Continuous Power Dissipation (T = +70C) A FREQ to GND ..........................................-0.3V to (V + 0.3V) 24-Pin TQFN (derate 27.8mW/C above +70C) ........2222mW DD OUT, EN to GND ......................................................-0.3V to +6V Thermal Resistance (Note 2) BST to LX..................................................................-0.3V to +6V .................................................................................36C/W JA BST to GND............................................................-0.3V to +12V ..................................................................................6C/W JC PGND to GND .......................................................-0.3V to +0.3V Operating Temperature Range ...........................-40C to +85C LX to PGND ..................-0.3V to the lower of +6V or (V + 0.3V) Junction Temperature......................................................+150C IN LX to PGND ..........-1V to the lower of +6V or (V + 1V) for 50ns Storage Temperature Range .............................-65C to +150C IN I (Note 1)......................................................................4A Lead Temperature (soldering, 10s) .................................+300C LX(RMS) Soldering Temperature (reflow) .......................................+260C Note 1: LX has internal clamp diodes to PGND and IN. Applications that forward bias these diodes should take care not to exceed the ICs package power dissipation limits. Note 2: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four- layer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial. 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 = V = 5V, C = 2.2F, T = T = -40C to +85C, typical values are at T = +25C, circuit of Figure 1, unless otherwise IN EN VDD A J A noted.) (Note 3) PARAMETER CONDITIONS MIN TYP MAX UNITS IN IN Voltage Range 2.9 5.5 V V = 3.3V 4.7 8 IN IN Supply Current f = 1MHz, no load mA S V = 5V 5 8.5 IN V = 5V, V = 0V 10 20 IN EN Total Shutdown Current from IN A V = V = 3.3V, V = 0V 45 IN DD EN 3.3V LDO (V ) DD V rising 2.6 2.8 DD V V falling 2.35 2.55 V Undervoltage Lockout DD DD LX starts/stops switching Threshold Minimum glitch-width 10 s rejection V Output Voltage V = 5V, I = 0 to 10mA 3.1 3.3 3.5 V DD IN VDD V Dropout V = 2.9V, I = 10mA 0.08 V DD IN VDD V Current Limit V = 5V, V = 0V 25 40 mA DD IN DD BST BST Supply Current V = V = 5V, V = 0 or 5V, V = 0V 0.025 A BST IN LX EN PWM COMPARATOR PWM Comparator Propagation 10mV overdrive 20 ns Delay PWM Peak-to-Peak Ramp 1V Amplitude PWM Valley Amplitude 0.8 V 2 MAX15038