Dual, 4A/2A, 4MHz, Step-Down MAX15021 DC-DC Regulator withTracking/ Sequencing Capability General Description Benefits and Features The MAX15021 is a dual-output, pulse-width-modulated Integration Reduces Power-Supply Footprint for Space- (PWM), step-down DC-DC regulator with tracking (coin- Constrained Designs cident and ratiometric) and sequencing options. The Dual-Output Synchronous Buck Regulators device operates from 2.5V to 5.5V and each output can Integrated Switches for 4A and 2A Output Currents be adjusted from 0.6V to the input supply (V ). The AVIN Programmable Switching Frequency from 500kHz MAX15021 delivers up to 4A (regulator 1) and 2A (reg- to 4MHz ulator 2) of output current. This device offers the ability 28-Pin TQFN Package (5mm x 5mm) to adjust the switching frequency from 500kHz to 4MHz 180 Out-Of-Phase Operation Reduces Input and provides the capability of optimizing the design in Ripple Current and Thus the Size of the Input terms of size and performance. Bypass Capacitors The MAX15021 utilizes a voltage-mode control scheme Sophisticated Tracking/Sequencing Functions with external compensation to provide good noise Facilitate Reliable Processor Operation immunity and maximum flexibility in selecting inductor Digital Soft-Start and Soft-Stop for Tracking values and capacitor types. The dual switching regula- Applications tors operate 180 out-of-phase, thereby reducing the Digital Soft-Start into a Prebiased Load for RMS input ripple current and thus the size of the input Sequencing Applications bypass capacitor significantly. Sequencing or Coincident/Ratiometric Tracking The MAX15021 offers the ability to track (coincident or Flexible Enough for Use in a Range of Designs ratiometric) or sequence during power-up and power- 2.5V to 5.5V Input Voltage Range down operation. When sequencing, it powers up glitch- Output-Voltage Adjustable from 0.6V to V free into a prebiased output. AVIN External Compensation for Maximum Flexibility Additional features include an internal undervoltage 100% Maximum Duty Cycle lockout with hysteresis and a digital soft-start/soft-stop Integrated Protection Features Save Space and for glitch-free power-up and power-down. Protection Increase Reliability features include lossless cycle-by-cycle current limit, hiccup-mode output short-circuit protection, and ther- Lossless, Cycle-by-Cycle Current Sensing mal shutdown. Thermal Shutdown and Hiccup-Mode Short-Circuit Protection The MAX15021 is available in a space-saving, 5mm x 5mm, 28-pin TQFN-EP package and is specified for 20A Shutdown Current Extends Battery Life in operation from -40C to +125C temperature range. Portable Applications Applications Pin Configuration RFID Reader Cards TOP VIEW Power-over-Ethernet (PoE) IP Phones Automotive Multimedia 21 20 19 18 17 16 15 Multivoltage Supplies N.C. 22 14 N.C. COMP2 23 13 N.C. Networking/Telecom FB2 24 12 COMP1 MAX15021 25 11 FB1 EN2 Ordering Information SGND 26 10 EN1 AVIN 27 9 DVDD1 PART TEMP RANGE PIN-PACKAGE *EP + RT 28 8 PGND1 MAX15021ATI/V+ -40C to +125C 28 TQFN-EP* 1 2 3 4 56 7 /V denotes an automotive qualified part. +Denotes a lead(Pb)-free/RoHS-compliant package. *EP = Exposed pad. *EP = EXPOSED PAD. 19-4106 Rev 2 4/15 SEL N.C. PGND1 N.C. LX1 PVIN2 PVIN1 LX2 PVIN1 PGND2 LX1 DVDD2 N.C. PGND1Dual, 4A/2A, 4MHz, Step-Down MAX15021 DC-DC Regulator withTracking/ Sequencing Capability Absolute Maximum Ratings AVIN, PVIN , DVDD , EN , FB , RT, Continuous Power Dissipation (T = +70C) A SEL to SGND.........................................................-0.3V to +6V 28-Pin TQFN (derate 34.5mW/C above +70C) .....2758.6mW COMP to SGND .....................................-0.3V to (V + 0.3V) Junction-to-Case Thermal Resistance ( )(Note 2) .........2C/W AVIN JC PGND to SGND ...................................................-0.3V to +0.3V Junction-to-Ambient Thermal Resistance ( )(Note 2) ..29C/W JA LX Current (Note 1) Operating Temperature Range .........................-40C to +125C Regulator 1...............................................................................6A Maximum Junction Temperature .....................................+150C Regulator 2...............................................................................3A Storage Temperature Range .............................-60C to +150C Current into Any Pin other than PVIN , Lead Temperature (soldering, 10s) .................................+300C 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. 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 see www.maximintegrated.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 = 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 20 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 POWER MOSFETs Regulator 1 p-Channel MOSFET V = 5V 50 90 m DVDD1 Regulator 1 n-Channel MOSFET V = 5V 30 50 m DVDD1 Regulator 1 Gate Charge V = 5V 8 nC DVDD1 Maximum LX1 RMS Current 4A Regulator 2 p-Channel MOSFET V = 5V 100 180 m DVDD2 Regulator 2 n-Channel MOSFET V = 5V 60 100 m DVDD2 Regulator 2 Gate Charge V = 5V 4 nC DVDD2 Maximum LX2 RMS Current 2A www.maximintegrated.com Maxim Integrated 2