MAX15022 19-4107 Rev 1 7/11 Dual, 4A/2A, 4MHz, Step-Down DC-DC Regulator with Dual LDO Controllers General Description Features The MAX15022 is a dual-output, pulse-width-modulated 2.5V to 5.5V Input-Voltage Range (PWM), step-down DC-DC regulator with dual LDO con- Dual-Output Synchronous Buck Regulators trollers. The device operates from 2.5V to 5.5V and Integrated Switches for 4A and 2A Output each output can be adjusted from 0.6V to the input Currents supply (V ). The MAX15022 delivers up to 4A (regu- AVIN lator 1) and 2A (regulator 2) of output current with two 180 Out-Of-Phase Operation LDO controllers that can be used to drive two external Output Voltage Adjustable from 0.6V to V AVIN PNP transistors to provide two additional outputs. This Two LDO Controllers device offers the ability to adjust the switching frequen- cy from 500kHz to 4MHz and provides the capability of Lossless, Cycle-by-Cycle Current Sensing optimizing the design in terms of size and performance. External Compensation for Maximum Flexibility The MAX15022 utilizes a voltage-mode control scheme Digital Soft-Start and Soft-Stop for Tracking with external compensation to provide good noise Applications immunity and maximum flexibility in selecting inductor Digital Soft-Start into a Prebiased Load for values and capacitor types. The dual switching regula- Sequencing Applications tors operate 180 out-of-phase, thereby reducing the RMS input ripple current and thus the size of the input Sequencing or Coincident/Ratiometric Tracking bypass capacitor significantly. Programmable Switching Frequency from 500kHz The MAX15022 offers the ability to track (coincident or to 4MHz ratiometric) or sequence during power-up and power- Thermal Shutdown and Hiccup-Mode Short- down operation. When sequencing, it powers up glitch- Circuit Protection free into a prebiased output. 30A Shutdown Current Additional features include an internal undervoltage 100% Maximum Duty Cycle lockout with hysteresis and a digital soft-start/soft-stop for glitch-free power-up and power-down. Protection Space-Saving (5mm x 5mm) 28-Pin TQFN features include lossless cycle-by-cycle current limit, Package hiccup-mode output short-circuit protection, and ther- mal shutdown. Pin Configuration The MAX15022 is available in a space-saving, 5mm x 5mm, 28-pin TQFN-EP package and is specified for TOP VIEW operation from -40C to +125C temperature range. 21 20 19 18 17 16 15 Applications B4 22 14 FB3 RFID Reader Cards 13 B3 COMP2 23 Power-over-Ethernet (PoE) IP Phones 24 12 COMP1 FB2 Automotive Multimedia FB1 25 11 EN2 Multivoltage Supplies MAX15022 26 10 SGND EN1 Networking/Telecom AVIN 27 9 DVDD1 *EP + Ordering Information RT 28 8 PGND1 PART TEMP RANGE PIN-PACKAGE 1 2 3 4 56 7 MAX15022ATI+ -40C to +125C 28 TQFN-EP* MAX15022ATI/V+ -40C to +125C 28 TQFN-EP* +Denotes a lead(Pb)-free/RoHS-compliant package. THIN QFN (5mm x 5mm) *EP = Exposed pad. /V denotes an automotive qualified part. *EP = EXPOSED PAD. 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 SEL FB4 PGND1 EN4 LX1 PVIN2 PVIN1 LX2 PVIN1 PGND2 LX1 DVDD2 PGND1 EN3Dual, 4A/2A, 4MHz, Step-Down DC-DC Regulator with Dual LDO Controllers ABSOLUTE MAXIMUM RATINGS AVIN, PVIN , B , DVDD , EN , FB , RT, Continuous Power Dissipation (T = +70C) A SEL to SGND.........................................................-0.3V to +6V TQFN (derate 34.5mW/C above +70C) ................2758.6mW COMP to SGND .....................................-0.3V to (V + 0.3V) Operating Temperature Range .........................-40C to +125C AVIN PGND to SGND ...................................................-0.3V to +0.3V Junction Temperature......................................................+150C LX Current (Note 1) Storage Temperature Range .............................-60C to +150C Regulator 1...............................................................................6A Lead Temperature (soldering, 10s) .................................+300C Regulator 2...............................................................................3A Soldering Temperature (reflow) .......................................+260C Current into Any Pin Other than PVIN , LX and PGND .............................................................50mA Note 1: LX has internal diodes to PGND and PVIN . Applications that forward bias these diodes should take care not to exceed the ICs package power dissipation limits. 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. PACKAGE THERMAL CHARACTERISTICS (Note 2) TQFN Junction-to-Ambient Thermal Resistance ( )...............29C/W JA Junction-to-Case Thermal Resistance ( )......................2C/W JC 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. ELECTRICAL CHARACTERISTICS (V = V = V = 3.3V, V = V = 0V, R = 25k , and T = T = -40C to +125C, unless otherwise noted. AVIN PVIN DVDD PGND SGND T A J Typical values are at T = +25C.) (Note 3) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS SYSTEM SPECIFICATIONS V = V = V = V = AVIN PVIN1 PVIN2 DVDD1 Input-Voltage Range 2.5 5.5 V V DVDD2 Undervoltage Lockout Threshold AVIN rising 2.1 2.2 2.3 V Undervoltage Lockout Hysteresis 0.12 V Operating Supply Current V = 1.3V, V = 0.8V 3.5 6 mA EN FB Shutdown Supply Current V = 0V 30 65 A EN PWM DIGITAL SOFT-START/SOFT-STOP Clock Soft-Start/Soft-Stop Duration 4096 Cycles Reference Voltage Steps 64 Steps PWM ERROR AMPLIFIERS FB1, FB2 Input Bias Current -1 +1 A FB1, FB2 Voltage Set-Point 0.593 0.599 0.605 V COMP1, COMP2 Voltage Range I = -250A to +250A 0.3 V - 0.5 V COMP AVIN Error-Amplifier Open-Loop Gain 80 dB Error-Amplifier Unity-Gain 12 MHz Bandwidth 2 MAX15022