EVALUATION KIT AVAILABLE MAXM17503 4.5V to 60V, 2.5A High-Efficiency, DC-DC Step-Down Power Module with Integrated Inductor General Description The Himalaya series of voltage regulator ICs and Power Modules enable cooler, smaller and simpler power supply solutions. The MAXM17503 is an easy-to-use, step-down power module that combines a switching power supply controller, dual n-channel MOSFET power switches, fully shielded inductor, and the compensation components in a low-profile, thermally-efficient, system-in-package (SiP). The device operates over a wide input voltage range of 4.5V to 60V and delivers up to 2.5A continuous output current with excellent line and load regulation over an output voltage range of 0.9V to 12V. The device only requires five external components to complete the total power solution. The high level of integration significantly reduces design complexity, manufacturing risks, and offers a true plug-and-play power supply solution, reducing time-to-market. The device can be operated in the pulse-width modulation (PWM), pulse-frequency modulation (PFM), or discontinuous conduction mode (DCM) control schemes. The MAXM17503 is available in a low-profile, highly thermal-emissive, compact, 29-pin 9mm x 15mm x 2.8mm SiP package that reduces power dissipation in the package and enhances efficiency. The package is easily soldered onto a printed circuit board and suitable for automated circuit board assembly. The device can operate over the industrial temperature range from -40C to +125C. Applications Industrial Power Supplies Distributed Supply Regulation FPGA and DSP Point-of-Load Regulator Base Station Point-of-Load Regulator HVAC and Building Control Benefits and Features Reduces Design Complexity, Manufacturing Risks, and Time-to-Market * Integrated Switching Power Supply Controller and Dual-MOSFET Power Switches * Integrated Inductor * Integrated Compensation Components * Integrated Thermal-Fault Protection * Integrated Peak Current Limit Saves Board Space in Space-Constrained Applications * Complete Integrated Step-Down Power Supply in a Single Package * Small Profile 9mm x 15mm x 2.8mm SiP Package * Simplified PCB Design with Minimal External BOM Components Offers Flexibility for Power-Design Optimization * Wide Input Voltage Range from 4.5V to 60V * Output-Voltage Adjustable Range from 0.9V to 12V * Adjustable Frequency with External Frequency Synchronization (100kHz to 1.8MHz) * Soft-Start Programmable * Autoswitch PWM, PFM, or DCM Current-Mode Control * Optional Programmable EN/UVLO Typical Application Circuit EN 4.5V TO 60V SYNC MODE IN VIN CIN RT RT OUT VCC OUT OUT OPTIONAL VCC OUT MAXM17503 RESET VOUT OUT OUT OUT SS COUT RU EP3 CSS FB CF EP1 Ordering Information appears at end of data sheet. 19-7451; Rev 2; 11/16 SGND PGND PGND RB MAXM17503 4.5V to 60V, 2.5A High-Efficiency, DC-DC Step-Down Power Module with Integrated Inductor Absolute Maximum Ratings (Notes 1, 2) IN to PGND (Note 2)..............................................-0.3V to +65V EN to SGND (Note 2).............................................-0.3V to +65V VCC..............................................-0.3V to min (VIN + 0.3V, 6.5V) FB, RESET, SS, CF, MODE, SYNC, RT to SGND..........................................-0.3V to +6.5V OUT to PGND (VIN < 25V)..........................-0.3V to (VIN + 0.3V) OUT to PGND (VIN 25V).....................................-0.3V to +25V LX to PGND................................................-0.3V to (VIN + 0.3V) BST to PGND.........................................................-0.3V to +70V BST to VCC............................................................-0.3V to +65V BST to LX..............................................................-0.3V to +6.5V Operating Temperature Range.......................... -40C to +125C Junction Temperature.......................................................+125C Storage Temperature Range............................. -65C to +125C Lead Temperature (soldering, 10s).................................. +245C 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 3) Junction-to-Ambient Thermal Resistance (JA)............30.8C/W Note 1: SGND and PGND are internally connected. Note 2: See the Pin Description for the connection of the backside exposed pad. Note 3: Data taken using Maxim's evaluation kit, MAXM17503EVKIT#. Electrical Characteristics (VIN = VEN = 24V, RRT = 40.2k (500kHz) to SGND, VPGND = VMODE = VSYNC = VSGND = 0V, VCC = LX = SS = RESET = OUT = open, VBST to VLX = 5V, VFB = 1V, TA = TJ = -40C to +125C, unless otherwise noted. Typical values are at TA = +25C. All voltages are referenced to SGND, unless otherwise noted.) (Note 4) PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS 60 V 13 A INPUT SUPPLY (VIN) IN Input Voltage Range VIN Input Shutdown Current IIN_SH VEN = 0V 10.5 MODE = RT = open 125 IQ_DCM MODE = VCC 1.16 IQ_PWM Normal switching mode, no load 9.5 IQ_PFM_HIB Input Quiescent Current 4.5 A 1.8 mA mA LOGIC INPUTS EN Threshold Enable Pullup Resistor VENR VEN rising 1.192 1.215 1.26 VENF VEN falling 1.068 1.09 1.131 RENP Pullup resistor between IN and EN pins 3.15 3.3 3.45 M VCC 6V < VIN < 60V, 1mA < IVCC < 25mA 4.75 5 5.25 V 60 100 mA V LDO VCC Output Voltage Range VCC Current Limit VCC Dropout VCC UVLO IVCC_MAX VIN = 6V, VCC = 4.3V 26.5 VCC_DO VIN = 4.5V, IVCC = 20mA 4.2 VCC_UVR VCC rising 4.05 4.2 4.3 VCC_UVF VCC falling 3.65 3.8 3.9 V V OUTPUT SPECIFICATIONS Line Regulation Accuracy VIN = 6.5V to 60V, VOUT = 5V 0.1 mV/V Load Regulation Accuracy Tested with IOUT = 0A and 1A 1 mV/A www.maximintegrated.com Maxim Integrated 2 MAXM17503 4.5V to 60V, 2.5A High-Efficiency, DC-DC Step-Down Power Module with Integrated Inductor Electrical Characteristics (continued) (VIN = VEN = 24V, RRT = 40.2k (500kHz) to SGND, VPGND = VMODE = VSYNC = VSGND = 0V, VCC = LX = SS = RESET = OUT = open, VBST to VLX = 5V, VFB = 1V, TA = TJ = -40C to +125C, unless otherwise noted. Typical values are at TA = +25C. All voltages are referenced to SGND, unless otherwise noted.) (Note 4) PARAMETER SYMBOL FB Regulation Voltage VFB_REG FB Input Bias Current IFB FB Undervoltage Trip Level to Cause Hiccup CONDITIONS MIN MODE = SGND 0.887 MODE = open 0.890 0V < VFB < 1V, TA = +25C Hiccup Timeout MAX 0.910 0.915 -50 0.56 VFB_HICF TYP 0.58 0.936 UNITS V +50 nA 0.65 V 32,768 Cycles SOFT-START (SS) Charging Current ISS VSS = 0.5V 4.7 5 5.3 RRT = 210k 90 100 110 A RT AND SYNC Switching Frequency fSW RRT = 9.76k RRT = open 450 500 SYNC Pulse Width kHz 550 1.4x fSW 1.1x fSW SYNC Frequency Range SYNC Threshold 1800 50 ns 2.1 VIH kHz VIL 0.8 V MODE MODE Threshold VM_DCM MODE = VCC (DCM mode) VM_PFM MODE = open (PFM mode) VM_PWM MODE = GND (PWM mode) VCC - 1.6 V VCC/2 1.4 CURRENT LIMIT Average Current-Limit Threshold RESET IAVG_LIMIT VOUT = VFB = 0.8V, fSW = 200kHz 3.45 RESET Output Level Low IRESET = 10mA RESET Output Leakage Current VRESET = 5.5V, TA = TJ = +25C -0.1 A 0.4 V +0.1 A FB Threshold for RESET Assertion VFB_OKF VFB falling 90.5 92 94.6 % FB Threshold for RESET Deassertion VFB_OKR VFB rising 93.8 95 97.8 % RESET Deassertion Delay After FB Reaches 95% Regulation 1024 Cycles +165 C 10 C THERMAL SHUTDOWN Thermal-Shutdown Threshold Thermal-Shutdown Hysteresis Temperature rising Note 4: All limits are 100% tested at TA = +25C. Maximum and minimum limits are guaranteed by design and characterized over temperature. www.maximintegrated.com Maxim Integrated 3 MAXM17503 4.5V to 60V, 2.5A High-Efficiency, DC-DC Step-Down Power Module with Integrated Inductor Typical Operating Characteristics (VIN = 4.5V to 60V, VOUT = 0.9 to 12V, IOUT = 0A-2.5A, TA = +25C, unless otherwise noted.) EFFICIENCY vs. OUTPUT CURRENT VOUT = 12V, PFM MODE 60 VIN = 36V, 70 0 500 1000 2000 fSW = 1.33MHz VIN = 36V, fSW = 1.8MHz 50 1500 VIN = 48V, fSW = 1.8MHz 60 40 2500 0 500 1000 80 70 60 1500 2000 40 2500 fSW = 740kHz VIN = 24V, VIN = 48V, fSW = 740kHz fSW = 500kHz MODE = OPEN 0 500 1000 1500 2000 2500 OUTPUT CURRENT (mA) OUTPUT CURRENT (mA) OUTPUT CURRENT (mA) EFFICIENCY vs. OUTPUT CURRENT VOUT = 5V, PWM MODE EFFICIENCY vs. OUTPUT CURRENT VOUT = 3.3V, PFM MODE EFFICIENCY vs. OUTPUT CURRENT VOUT = 3.3V, PWM MODE toc04 toc05 100 90 80 80 80 VIN = 36V, VIN = 12V, fSW = 740kHz fSW = 740kHz 60 VIN = 24V, VIN = 48V, fSW = 740kHz 50 fSW = 500kHz 500 1000 1500 2000 60 40 2500 OUTPUT CURRENT (mA) VIN = 48V, VIN = 12V, fSW = 500kHz 0 500 1000 fSW = 366kHz VIN = 36V, 1500 2000 EFFICIENCY (%) VIN = 24V, VIN = 48V, VIN = 5V, fSW = 400kHz fSW = 400kHz fSW = 277kHz MODE = OPEN 0 500 1000 1500 2000 OUTPUT CURRENT (mA) www.maximintegrated.com 500 2500 1000 1500 2000 2500 EFFICIENCY vs. OUTPUT CURRENT VOUT = 2.5V, PWM MODE toc08 100 80 40 0 OUTPUT CURRENT (mA) 80 VIN = 36V, VIN = 12V, fSW = 400kHz fSW = 400kHz VIN = 48V, fSW = 366kHz VIN = 36V, VIN = 12V, fSW = 500kHz fSW = 500kHz MODE = SGND OUTPUT CURRENT (mA) 90 50 60 40 2500 90 60 VIN = 24V, fSW = 500kHz MODE = OPEN toc07 70 70 50 fSW = 500kHz EFFICIENCY vs. OUTPUT CURRENT VOUT = 2.5V, PFM MODE 100 EFFICIENCY (%) VIN = 24V, fSW = 500kHz 50 MODE = SGND 0 70 EFFICIENCY (%) 90 70 toc06 100 90 40 VIN = 36V, VIN = 12V, fSW = 740kHz 50 MODE = SGND MODE = OPEN 100 EFFICIENCY (%) fSW = 1.33MHz fSW = 1.8MHz 50 40 VIN = 48V, fSW = 1.8MHz VIN = 24V, EFFICIENCY (%) 70 80 EFFICIENCY (%) VIN = 24V, EFFICIENCY (%) EFFICIENCY (%) 80 toc03 90 90 90 EFFICIENCY vs. OUTPUT CURRENT VOUT = 5V, PFM MODE 100 toc02 100 toc01 100 EFFICIENCY vs. OUTPUT CURRENT VOUT = 12V, PWM MODE 70 VIN = 12V, fSW = 400kHz 60 50 40 VIN = 5V, fSW = 400kHz 0 500 VIN = 36V, fSW = 400kHz VIN = 48V, VIN = 24V, fSW = 400kHz fSW = 277kHz 1000 MODE = SGND 1500 2000 2500 OUTPUT CURRENT (mA) Maxim Integrated 4 MAXM17503 4.5V to 60V, 2.5A High-Efficiency, DC-DC Step-Down Power Module with Integrated Inductor Typical Operating Characteristics (continued) (VIN = 4.5V to 60V, VOUT = 0.9 to 12V, IOUT = 0A-2.5A, TA = +25C, unless otherwise noted.) toc09 VIN = 5V, fSW = 350kHz VIN = 24V, 80 70 60 40 VIN = 36V, VIN = 12V, 50 fSW = 200kHz fSW = 350kHz 0 500 1000 1500 2000 70 VIN = 24V, fSW = 285kHz 40 2500 MODE = SGND 0 500 toc12 100 3.6 3.5 70 VIN = 12V, fSW = 300kHz 60 VIN = 5V, fSW = 300kHz 50 40 0 500 MODE=SGND 1000 1500 2000 3 2500 LOAD REGULATION VOUT = 5V, PFM MODE 5.4 VIN = 12V, fSW = 500kHz VIN = 36V 1000 fSW = 500kHz fSW = 366kHz 500 1000 1500 2000 VIN = 5.0V 3.4 3.3 2000 3 2500 2500 toc14 VIN = 12V fSW = 500kHz VIN = 36V fSW = 500kHz VIN = 24V fSW = 500kHz 3.1 MODE = OPEN 0 500 VIN = 48V fSW = 366kHz MODE=SGN D 1500 2000 2500 1000 OUTPUT CURRENT (mA) LOAD REGULATION VOUT = 5V, PWM MODE 5.5 VIN = 12V, 5.3 4.9 1500 fSW = 500kHz 3.2 VIN = 48V VOUT (V) VOUT (V) 3.5 VIN = 12V 5.4 5 MODE = OPEN 500 3.6 fSW = 500kHz toc15 5.1 VIN = 36V, fSW = 740kHz 5.2 toc16 fSW = 740kHz 5.1 5 4.9 4.8 VIN = 48V, 4.7 fSW = 500kHz 4.6 4.5 toc13 fSW = 740kHz 5.2 0 LOAD REGULATION VOUT = 3.3V, PWM MODE VIN = 36V, fSW = 740kHz 5.3 fSW = 214kHz LOAD REGULATION VOUT = 3.3V, PFM MODE VIN = 24V 0 VIN = 24V, VIN = 5V, fSW = 300kHz OUTPUT CURRENT (mA) OUTPUT CURRENT (mA) 5.5 40 2500 3.3 3.1 VIN = 12V, fSW = 300kHz 60 OUTPUT CURRENT (mA) VIN = 5.0V 3.4 2000 70 OUTPUT CURRENT (mA) fSW = 500kHz 3.2 VIN = 24V, fSW = 214kHz 1500 VOUT (V) 80 VOUT (V) EFFICIENCY (%) 90 1000 80 50 fSW = 200kHz fSW = 350kHz OUTPUT CURRENT (mA) EFFICIENCY vs. OUTPUT CURRENT VOUT = 0.9V, PWM MODE VIN = 36V, VIN = 12V, 50 MODE = OPEN 90 80 60 toc11 100 VIN = 5V, fSW = 350kHz 90 fSW = 285kHz EFFICIENCY (%) EFFICIENCY (%) 90 toc10 100 EFFICIENCY (%) 100 EFFICIENCY vs. OUTPUT CURRENT VOUT = 0.9V, PFM MODE EFFICIENCY vs. OUTPUT CURRENT VOUT = 1.2V, PWM MODE EFFICIENCY vs. OUTPUT CURRENT VOUT = 1.2V, PFM MODE 0 500 4.8 VIN = 24V, MODE = OPEN 1000 1500 2000 OUTPUT CURRENT (mA) www.maximintegrated.com VIN = 24V, 4.7 fSW = 740kHz 2500 fSW = 740kHz 4.6 4.5 VIN = 48V, fSW = 500kHz MODE = SGND 0 500 1000 1500 2000 2500 OUTPUT CURRENT (mA) Maxim Integrated 5 MAXM17503 4.5V to 60V, 2.5A High-Efficiency, DC-DC Step-Down Power Module with Integrated Inductor Typical Operating Characteristics (continued) (VIN = 4.5V to 60V, VOUT = 0.9 to 12V, IOUT = 0A-2.5A, TA = +25C, unless otherwise noted.) LOAD REGULATION VOUT = 12V, PFM MODE 13 toc17 VOUT (V) 12.2 12 11.8 fSW = 1.33MHz 11.4 VIN = 36V, 12.20 12.00 0 500 1000 1500 2000 2500 0 500 1000 1500 2000 2s/div INPUT VOLTAGE RIPPLE VIN = 24V, VOUT = 5V, IOUT = 2.5A, MODE = SGND toc22 INPUT VOLTAGE RIPPLE VIN = 24V, VOUT = 3.3V, IOUT = 2.5A, MODE = SGND toc21 toc20 100mV/div (ACCOUPLED) VIN 2s/div 200mV/div (ACCOUPLED) VIN 2s/div 2s/div LOAD CURRENT TRANSIENT RESPONSE VIN = 24V, VOUT = 3.3V, IOUT = 0.05A - 1.25A, toc23 MODE = OPEN IOUT 1A/div VOUT 200mV/div (AC COUPLED) 200s/div www.maximintegrated.com 2500 OUTPUT CURRENT (mA) 20mV/div (ACCOUPLED) VOUT VIN = 36V, MODE = SGND OUTPUT CURRENT (mA) OUTPUT VOLTAGE RIPPLE VIN = 24V, VOUT = 5V, IOUT = 2.5A, MODE = SGND fSW = 1.33MHz fSW = 1.8MHz 11.20 11.00 VIN = 48V, VIN = 24V, fSW = 1.8MHz 11.40 MODE = OPEN 20mV/div (ACCOUPLED) VOUT 11.60 fSW = 1.8MHz 11.2 11 toc19 12.40 11.80 VIN = 48V, toc18 12.60 12.4 11.6 OUTPUT VOLTAGE RIPPLE VIN = 24V, VOUT = 3.3V, IOUT = 2.5A, MODE = SGND 12.80 fSW = 1.8MHz 12.6 VOUT (V) 13.00 VIN = 24V, 12.8 LOAD REGULATION VOUT = 12V, PWM MODE LOAD CURRENT TRANSIENT RESPONSE VIN = 24V, VOUT = 3.3V, IOUT = 0.05A - 1.25A, MODE = SGND toc24 IOUT 1A/div 200mV/div (AC COUPLED) VOUT 100s/div Maxim Integrated 6 MAXM17503 4.5V to 60V, 2.5A High-Efficiency, DC-DC Step-Down Power Module with Integrated Inductor Typical Operating Characteristics (continued) (VIN = 4.5V to 60V, VOUT = 0.9 to 12V, IOUT = 0A-2.5A, TA = +25C, unless otherwise noted.) LOAD CURRENT TRANSIENT RESPONSE VIN = 24V, VOUT = 3.3V, IOUT = 0.05A - 1.25A, MODE = VCC toc25 1A/div IOUT 200mV/div (AC COUPLED) VOUT 1A/div IOUT 200mV/div (AC COUPLED) VOUT LOAD CURRENT TRANSIENT RESPONSE VIN = 24V, VOUT = 5V, IOUT = 0.05A - 1.25A, MODE = VCC toc28 STARTUP THROUGH ENABLE VIN = 24V, VOUT = 3.3V, IOUT = 0A, MODE = SGND STARTUP WITH 2.5V PREBIAS VIN = 24V, VOUT = 3.3V, IOUT = 0A, MODE = SGND toc30 toc29 5V/div 20V/div LX 1A/div 2V/div 200mV/div (AC COUPLED) VOUT LX toc31 5V/div EN 20V/div LX 5V/div RESET 5V/div 1ms/div SHUTDOWN THROUGH ENABLE VIN = 24V, VOUT = 3.3V, IOUT = 0A, MODE = SGND 2V/div VOUT 2V/div VOUT 1ms/div EN 20V/div LX RESET 100s/div STARTUP WITH 2.5V PREBIAS VIN = 24V, VOUT = 3.3V, IOUT = 0A, MODE = OPEN 5V/div EN 5V/div RESET toc32 5V/div 20V/div 2V/div VOUT RESET 5V/div 1ms/div www.maximintegrated.com 200mV/div (AC COUPLED) VOUT 100s/div EN VOUT 1A/div IOUT 200s/div 100s/div IOUT LOAD CURRENT TRANSIENT RESPONSE VIN = 24V, VOUT = 5V, IOUT = 0.05A - 1.25A, toc27 MODE = SGND LOAD CURRENT TRANSIENT RESPONSE VIN = 24V, VOUT = 5V, IOUT = 0.05A - 1.25A, toc26 MODE = OPEN 1ms/div Maxim Integrated 7 MAXM17503 4.5V to 60V, 2.5A High-Efficiency, DC-DC Step-Down Power Module with Integrated Inductor Typical Operating Characteristics (continued) (VIN = 4.5V to 60V, VOUT = 0.9 to 12V, IOUT = 0A-2.5A, TA = +25C, unless otherwise noted.) STARTUP THROUGH INPUT SUPPLY VIN = 24V, VOUT = 3.3V, IOUT = 2.5A, MODE = SGND toc33 SHUTDOWN THROUGH INPUT SUPPLY VIN = 24V, VOUT = 3.3V, IOUT = 2.5A, toc34 MODE = SGND 10V/div VIN 20V/div LX VIN 20V/div LX 20V/div 2V/div VOUT 5V/div 2V/div VOUT 5V/div RESET RESET 100s/div 1ms/div SHUTDOWN THROUGH ENABLE VIN = 24V, VOUT = 5V, IOUT = 0A, MODE = SGND STARTUP THROUGH ENABLE VIN = 24V, VOUT = 5V, IOUT = 0A, MODE = SGND toc36 toc35 5V/div EN 20V/div LX 5V/div EN 20V/div LX 2V/div 2V/div VOUT 5V/div RESET VOUT 1ms/div 1ms/div STARTUP THROUGH INPUT SUPPLY VIN = 24V, VOUT = 5V, IOUT = 2.5A, MODE = SGND toc37 SHUTDOWN THROUGH INPUT SUPPLY VIN = 24V, VOUT = 5V, IOUT = 2.5A, toc38 MODE = SGND 10V/div 10V/div VIN 20V/div LX 20V/div VOUT 2V/div VIN LX 2V/div VOUT 5V/div RESET 5V/div RESET 5V/div RESET 1ms/div www.maximintegrated.com 100s/div Maxim Integrated 8 MAXM17503 4.5V to 60V, 2.5A High-Efficiency, DC-DC Step-Down Power Module with Integrated Inductor Typical Operating Characteristics (continued) (VIN = 4.5V to 60V, VOUT = 0.9 to 12V, IOUT = 0A-2.5A, TA = +25C, unless otherwise noted.) OUTPUT SHORT IN STEADY STATE VIN = 24V, VOUT = 3.3V, IOUT = 0A to SHORT MODE = SGND toc39 OUTPUT SHORT DURING STARTUP VIN = 24V, VOUT = 3.3V, IOUT = SHORT, MODE = SGND toc40 VIN 20V/div 20V/div VIN LX 20V/div LX 20V/div VOUT 2V/div VOUT 2V/div IOUT 10A/div IOUT 10A/div 40ms/div SYNC FREQUENCY AT 740 KHZ VIN = 24V, VOUT = 5V, IOUT = 0A, MODE = GND toc41 50.00 CLOSED-LOOP BODE PLOT VIN = 24V, VOUT = 3.3V, IOUT = 2.5A, MODE = SGND 40.00 SYNC GAIN (dB) LX PHASE 30.00 5V/div 20V/div 2V/div 150 120 90 20.00 60 10.00 30 0.00 0 GAIN -10.00 VOUT toc42 -30 -20.00 -60 -30.00 CROSSOVER FREQUENCY = 54.9kHz PHASE MARGIN = 53.3 -40.00 -50.00 2s/div 1k 10k 100k PHASE MARGIN () 40ms/div -90 -120 -150 1Meg FREQUENCY (Hz) 3.5 OUTPUT CURRENT vs. AMBIENT TEMPERATURE VIN = 24V NO AIR FLOW toc43 OUTOPUT CURRENT (A) 3 VOUT = 3.3V 2.5 2 1.5 VOUT = 5V 1 0.5 0 VOUT = 12V 0 10 20 30 40 50 60 70 80 90 100110120 AMBIENT TEMPERATURE (C) www.maximintegrated.com Maxim Integrated 9 2 column (6.96 in.) MAXM17503 4.5V to 60V, 2.5A High-Efficiency, DC-DC Step-Down Power Module with Integrated Inductor Pin Configuration N.C. SYNC RESET EN 29 28 1 IN PGND 27 26 BST 25 LX LX LX 24 23 22 2 21 LX 20 LX EP2 SS 3 CF 4 FB 5 19 LX EP1 18 OUT 17 OUT 16 OUT EP3 RT 6 N.C. 7 11 8 MODE www.maximintegrated.com 9 VCC 10 SGND PGND 12 13 14 15 OUT OUT OUT OUT Maxim Integrated 10 MAXM17503 4.5V to 60V, 2.5A High-Efficiency, DC-DC Step-Down Power Module with Integrated Inductor Pin Description PIN NAME 1, 7 N.C. 2 SYNC 3 SS Soft-Start Input. Connect a capacitor from SS to SGND to set the soft-start. 4 CF Compensation Filter. Connect capacitor from CF to FB to correct frequency response with switching frequency below 500kHz. Leave CF open otherwise. 5 FB Feedback Input. Connect FB to the center tap of an external resistor-divider from the OUT to SGND to set the output voltage. See the Setting the Output Voltage section for more details. 6 RT Frequency Set. Connect a resistor from RT to SGND to set the regulator's switching frequency. Leave RT open for the default 500kHz frequency. 8 MODE 9 VCC 10 SGND Analog Ground. Internally-shorted to PGND. Connect it to PGND through a single point at output capacitor. 11, 26 PGND Power Ground. Connect the PGND pins externally to the power ground plane. 12-18 OUT 19-24 IC 25 BST 27 IN Input Supply Connection. Bypass to PGND with a capacitor; place the capacitor close to the IN and PGND pins. See Table 1 for more details 28 EN Enable/Undervoltage-Lockout Input. Default enable through the pullup 3.3M resistor between EN and IN. Connect a resistor from EN to SGND to set the UVLO threshold. If the EN/UVLO pin is driven by an external signal, a 50 damping resistor in series with the signal line driving EN/ UVLO is required. 29 RESET Open-Drain RESET Output. The RESET output is driven low if FB drops below 92% of its set value. RESET goes high 1024 clock cycles after FB rises above 95% of its set value. EP1 SGND Analog Ground. Connect this pad to 1in x 1in copper island with a lot of vias for cooling. EP2 LX EP3 OUT www.maximintegrated.com FUNCTION No Connection Frequency Synchronization. The device can be synchronized to an external clock using this pin. See the External Frequency Synchronization section for more details. Light-Load Mode Selection. The MODE pin configures the MAXM17504 to operate in PWM, PFM, or DCM mode of operation. Leave MODE unconnected for PFM operation (pulse skipping at light loads). Connect MODE to SGND for constant-frequency PWM operation at all loads. Connect MODE to VCC for DCM operation. See the MODE Selection (MODE) section for more details. 5V LDO Output. No external connection. Regulator Output Pin. Connect a capacitor from OUT to PGND. See PCB Layout Guidelines section for more connection details. Internally Connected to EP2. Please do not connect these pins to external components for any reason. Boost Flying Cap Node. No external connection. Switching Node. Connect this pad to a small copper area of 1in x 1in under the device for thermal relief. Connect this pad to the OUT pins and copper area of 1in x 1in. Maxim Integrated 11 MAXM17503 4.5V to 60V, 2.5A High-Efficiency, DC-DC Step-Down Power Module with Integrated Inductor Functional Diagram MAXM17503 5V VCC IN LDO 0.47F 2.2F SGND BST 3.3M VIN 0.1F LX EN 1.215V HICCUP RT OSCILLATOR PEAK CURRENT-MODE CONTROLLER 6.8H OUT 4.7F SYNC PGND CF MODE SELECTION LOGIC MODE FB RESET SS www.maximintegrated.com FB RESET LOGIC Maxim Integrated 12 MAXM17503 4.5V to 60V, 2.5A High-Efficiency, DC-DC Step-Down Power Module with Integrated Inductor Design Procedure Input Capacitor Selection Setting the Output Voltage The MAXM17503 supports an adjustable output voltage range of 0.9V to 12V from an input voltage range of 4.5V to 60V by using a resistive feedback divider from OUT to FB. Table 1 provides the feedback dividers for desired input and output voltages. Other adjustable output voltages can be calculated by following the procedure to choose the resistive voltage-divider values: Calculate resistor RU from the output to FB as follows: RU = 216 x 1000 f C x C OUT Where RU is in k, crossover frequency (fC) is in kHz, and output capacitor (COUT) is in F. Choose fC to be 1/9th of the switching frequency (fSW) if the switching frequency is less than or equal to 500kHz. If the switching frequency is more than 500kHz, select fC to be 55kHz. The input capacitor serves to reduce the current peaks drawn from the input power supply and reduces switching noise to the IC. The input capacitor values in Table 1 are the minimum recommended values for desired input and output voltages. Applying capacitor values larger than those indicated in Table 1 are acceptable to improve the dynamic response. For further operating conditions, the total input capacitance must be greater than or equal to the value given by the following equation in order to keep the input-voltage ripple within specifications and minimize the high-frequency ripple current being fed back to the input source: CIN = IIN_AVG x (1 - D) VIN x fSW where: IIN_AVG is the average input current given by: R x 0.9 RB = U k, where R B is in k. VOUT - 0.9 IIN_AVG = POUT x VIN D is the operating duty cycle, which is approximately equal to VOUT/VIN. OUT VOUT RU MAXM17503 VIN is the required input voltage ripple. fSW is the operating switching frequency. POUT is the out power, which is equal to VOUT x IOUT. is the efficiency. FB RB The input capacitor must meet the ripple-current requirement imposed by the switching currents. The RMS input ripple current is given by: IRMS = I OUT x D x (1 - D) Figure 1. Adjustable Output Voltage Input Voltage Range Due to the limitation of minimum and maximum duty cycle, the maximum value (VIN (MAX)) and minimum value (VIN (MIN)) must accommodate the worst-case conditions, accounting for the input voltage rises and drops. To simplify, Table 1 provides operating input voltage ranges of different desired output voltages. www.maximintegrated.com The worst-case RMS current requirement occurs when operating with D = 0.5. At this point, the above equation simplifies to IRMS = 0.5 x IOUT. For the MAXM17503 system (IN) supply, ceramic capacitors are preferred due to their resilience to inrush surge currents typical of systems, and due to their low parasitic inductance that helps reduce the high-frequency ringing on the IN supply when the internal MOSFETs are turned off. Choose an input capacitor that exhibits less than +10C temperature rise at the RMS input current for optimal circuit longevity. Maxim Integrated 13 MAXM17503 4.5V to 60V, 2.5A High-Efficiency, DC-DC Step-Down Power Module with Integrated Inductor Table 1. Selection Component Values VIN (V) VOUT (V) CIN COUT RU (k) RB (k) fSW (kHz) RT (k) 4.5 to 15 0.9 3 x 2.2F 1206 100V 2 x 100F 1210 4V 68.1 1 3 x 2.2F 1206 100V 2 x 100 F 1210 4V OPEN 300 4.5 to 15 35.7 68.1 1.2 3 x 2.2F 1206 100V 1 x 100F 1 x 47F 1210 4V 324 300 4.5 to 15 35.7 57.6 1.5 3 x 2.2F 1206 100V 1 x 100F 1 x 47F 1210 4V 124 350 4.5 to 15 41.2 4.5 to 15 1.8 3 x 2.2F 1206 100V 1 x 100F 1210 4V 57.6 86.6 4.5 to 15 2.5 3 x 2.2F 1206 100V 1 x 100F 1210 4V 61.9 61.9 4.5 to 15 3.3 2 x 2.2F 1206 100V 1 x 47F 1210 10V 53.6 30.1 6.5 to 15 5 2 x 2.2F 1206 100V 1 x 22F 1210 10V 130 48.7 11 to 15 8 2 x 2.2F 1206 100V 1 x 10F 1210 16V 191 42.2 4.5 to 28 0.9 3 x 2.2F 1206 100V 3 x 100F 1210 4V 309 39.2 4.5 to 28 1 3 x 2.2F 1206 100V 3 x 100F 1210 4V 35.7 OPEN 4.5 to 28 1.2 3 x 2.2F 1206 100V 2 x 100F 1210 4V 35.7 324 4.5 to 28 1.5 3 x 2.2F 1206 100V 1 x 100F 1 x 47F 1210 4V 41.2 124 4.5 to 28 1.8 3 x 2.2F 1206 100V 1 x 100F 1210 4V 57.6 86.6 4.5 to 28 2.5 3 x 2.2F 1206 100V 1 x 100F 1210 4V 61.9 61.9 4.5 to 28 53.6 30.1 130 48.7 191 42.2 309 39.2 464 37.4 41.2 124 57.6 86.6 61.9 61.9 53.6 30.1 130 48.7 191 42.2 309 39.2 464 37.4 61.9 61.9 97.6 54.9 59 22.1 137 30.1 309 39.2 464 37.4 3.3 2 x 2.2F 1206 100V 1 x 47F 1210 10V 6.5 to 28 5 2 x 2.2F 1206 100V 1 x 22F 1210 10V 11 to 28 18.5 to 28 4.5 to 40 8 2 x 2.2F 1206 100V 1 x 10F 1210 16V 12 2 x 2.2F 1206 100V 1 x 4.7F 1210 16V 1.2 3 x 2.2F 1206 100V 2 x 100F 1 x 47F 1210 4V 4.5 to 40 1.5 3 x 2.2F 1206 100V 1 x 100F 1 x 47F 1210 4V 4.5 to 40 1.8 3 x 2.2F 1206 100V 1 x 100F 1 x 47F 1210 4V 4.5 to 40 2.5 3 x 2.2F 1206 100V 1 x 100F 1210 4V 4.5 to 40 3.3 2 x 2.2F 1206 100V 1 x 47F 1210 10V 6.5 to 40 5 2 x 2.2F 1206 100V 1 x 22F 1210 10V 11 to 40 18.5 to 40 4.5 to 60 8 2 x 2.2F 1206 100V 1 x 10F 1210 16V 12 2 x 2.2F 1206 100V 1 x 4.7F 1210 16V 1.8 3 x 2.2F 1206 100V 2 x 100F 1210 4V 6 to 60 2.5 3 x 2.2F 1206 100V 1 x 100F 1210 4V 8 to 60 3.3 3 x 2.2F 1206 100V 2 x 47F 1210 10V 11 to 60 5 2 x 2.2F 1206 100V 1 x 47F 1210 10V 17 to 60 8 2 x 2.2F 1206 100V 1 x 10F 1210 16V 25 to 60 12 2 x 2.2F 1206 100V 1 x 4.7F 1210 16V www.maximintegrated.com 350 57.6 350 57.6 400 49.9 500 OPEN 740 26.7 1200 15.8 214 95.3 238 86.6 285 71.5 350 57.6 350 57.6 400 49.9 500 OPEN 740 26.7 1200 15.8 1800 10.0 200 100.00 250 82.5 300 68.1 400 49.90 500 OPEN 740 26.7 1200 15.8 1800 10.00 200 100.0 277 73.2 366 54.9 500 OPEN 888 21.5 1333 14.0 Maxim Integrated 14 MAXM17503 4.5V to 60V, 2.5A High-Efficiency, DC-DC Step-Down Power Module with Integrated Inductor Output Capacitor Selection The X7R ceramic output capacitors are preferred due to their stability over temperature in industrial applications. The minimum recommended output capacitor values in Table 1 are for desired output voltages to support a dynamic step load of 50% of the maximum output current in the application. For additional adjustable output voltages, the output capacitance value is derived from the following equation: I xt C OUT = STEP RESPONSE 2 x VOUT t RESPONSE 0.33 fC + 1 f SW where ISTEP is the step load transient, tRESPONSE is the response time of the controller, VOUT is the allowable output ripple voltage during load transient, fC is the target closed-loop crossover frequency, and fSW is the switching frequency. Select fC to be 1/9th of fSW or 55kHz if the fSW greater than 500kHz. Loop Compensation The MAXM17503 integrates the internal compensation to stabilize the control loop. Only the device requires a combination of output capacitors and feedback resistors to program the closed-loop crossover frequency (fC) at 1/9th of switching frequency. Use Table 1 to select component values to compensate with appropriate operating switching frequency. Connect a 0402 ceramic capacitor from CF to FB to correct frequency response with switching frequency below 500kHz. Place a 2.2pF capacitor for switching frequency below 300kHz, 1.2pF for 300kHz to 400kHz switching frequency range. Setting the Switching Frequency (RT) The switching frequency range of 100kHz to 1.8MHz are recommended from Table 1 for desired input and output voltages. The switching frequency of MAXM17503 can be programmed by using a single resistor (RRT) connected from the RT pin to SGND. The calculation of RRT resistor is given by the following equation: R RT 21000 - 1.7 f SW where RRT is in k and fSW is in kHz. Leaving the RT pin open to operate at the default switching frequency of 500kHz. www.maximintegrated.com Soft-Start Capacitor Selection The device implements an adjustable soft-start operation to reduce inrush current during startup. A capacitor (CSS) connected from the SS pin to SGND to program the soft-start time. The selected output capacitance (CSEL) and the output voltage (VOUT) determine the minimum value of CSS, as shown by the following equation: CSS SEL x VOUT where CSS is in nF and CSEL is in F. The value of the soft-start capacitor is calculated from the desired soft-start time as follows: t SS CSS 5.55 where tSS is in ms and CSS is in nF. Detailed Description The MAXM17503 is a complete step-down DC-DC power supply that delivers up to 2.5A output current. The device provides a programmable output voltage to regulate up to 12V through external resistor dividers from an input voltage range of 4.5V to 60V. The recommended input voltage in Table 1 is selected highly enough to support the desired output voltage and load current. The device includes an adjustable frequency feature range from 100kHz to 1.8MHz to reduce sizes of input and output capacitors. The Functional Diagram shows a complete internal block diagram of the MAXM17503 power module. Input Undervoltage-Lockout Level The MAXM17503 contains an internal pullup resistor (3.3M) from EN to IN to have a default startup voltage. The device offers an adjustable input undervoltagelockout level to set the voltage at which the device is turned on by a single resistor connecting from EN/UVLO to SGND as equation: R ENU 3.3 x 1215 (VINU - 1.215) where RENU is in k and VINU is the voltage at which the device is required to turn on the device. Ensure that VINU is high enough to support the VOUT. See Table 1 to set the proper VINU voltage greater than or equal the minimum input voltage for each desired output voltage. Maxim Integrated 15 MAXM17503 4.5V to 60V, 2.5A High-Efficiency, DC-DC Step-Down Power Module with Integrated Inductor Mode Selection (MODE) The MAXM17503 features a MODE pin to configure the device operating in PWM, PFM, or DCM control schemes. The device operates in PFM mode at light loads if the MODE pin is open. If the MODE pin connects to ground, the device operates in constant-frequency PWM mode at all loads. The device operates in constant-frequency DCM mode at light loads when the MODE pin connects to VCC. State changes of the MODE operation are only at power-up and ignore during normal operation. PWM Mode Operation In PWM mode, the step-down controller is switching a constant-frequency at all loads with a minimum sink current limit threshold (-1.8A typ) at light load. The PWM mode of operation gives lower efficiency at light loads compared to PFM and DCM modes of operation. However, the PWM mode of operation is useful in applications sensitive to switching frequency. PFM Mode Operation In PFM mode, the controller forces the peak inductor current in order to feed the light loads and maintain high efficiency. If the load is lighter than the average PFM value, the output voltage will exceed 102.3% of the feedback threshold and the controller enters into a hibernation mode, turning off most of the internal blocks. The device exits hibernation mode, and starts switching again, once the output voltage is discharged to 101.1% of the feedback threshold. The device then begins the process of delivering pulses of energy to the output repeatedly until it reaches 102.3% of the feedback threshold. In this mode, the behavior resembles PWM operation (with occasional pulse skipping), where the inductor current does not need to reach the light-load level. PFM mode offers the advantage of increased efficiency at light loads due to a lower quiescent current drawn from the supply. However, the output-voltage ripple is also increased as compared to the PWM or DCM modes of operation, and the switching frequency is not constant at light loads. DCM Mode Operation DCM mode features constant frequency operation down to lighter loads than PFM mode, accomplished by not skipping pulses. DCM efficiency performance lies between the PWM and PFM modes. www.maximintegrated.com External Frequency Synchronization (SYNC) The device can be synchronized by an external clock signal on the SYNC pin. The external synchronization clock frequency must be between 1.1 x fSW and 1.4 x fSW, where fSW is the frequency programmed by the RT resistor. The minimum external clock high pulse width and amplitude should be greater than 50ns and 2.1V respectively. The minimum external clock low pulse width should be greater than 160ns, and the maximum external clock low pulse amplitude should be less than 0.8V. Table 1 provides recommended synchronous frequency ranges for desired output voltages. Connect the SYNC pin to SGND if it is not used. RESET Output The device includes a RESET comparator to monitor the output for undervoltage and overvoltage conditions. The open-drain RESET output requires an external pullup resistor from 10k to 100k to VCC pin or maximum 6V voltage source. RESET goes high impedance after the regulator output increases above 95% of the designed nominal regulated voltage. RESET goes low when the regulator output voltage drops below 92% of the nominal regulated voltage. RESET also goes low during thermal shutdown. Thermal Fault Protection The MAXM17503 features a thermal-fault protection circuit. When the junction temperature rises above +165C (typ), a thermal sensor activates the fault latch, pulls down the RESET output, and shuts down the regulator. The thermal sensor restarts the controllers after the junction temperature cools by 10C (typ). The Soft-start resets during thermal shutdown. Power Dissipation and Output-Current Derating The MAXM17503 output current needs to be derated if the device needs to be operated in a high ambienttemperature environment. The amount of current-derating depends upon the input voltage, output voltage, and ambient temperature. The derating curves in TOC43 from the Typical Operating Characteristics section can be used as guidelines. The curves are based on simulating thermal resistance model (JT), measuring thermal resistance (TA), and measuring power dissipation (PDMAX) on the bench. Maxim Integrated 16 MAXM17503 4.5V to 60V, 2.5A High-Efficiency, DC-DC Step-Down Power Module with Integrated Inductor The maximum allowable power losses can be calculated using the following equation: T - TA PDMAX = JMAX JA where: PDMAX is the maximum allowed power losses with maximum allowed junction temperature. TJMAX is the maximum allowed junction temperature. Keep the resistive feedback dividers as close as possible to the FB pin. Connect all of the PGND connections to as large as copper plane area as possible on the bottom layer. Connect EP1 to PGND and GND planes on bottom layer. Use multiple vias to connect internal PGND planes to the top layer PGND plane. Do not keep any solder mask on EP1, EP2, and EP3 on bottom layer. Keeping solder mask on exposed pads decreases the heat dissipating capability. Keep the power traces and load connections short. This practice is essential for high efficiency. Using thick copper PCBs (2oz vs. 1oz) can enhance full-load efficiency. Correctly routing PCB traces is a difficult task that must be approached in terms of fractions of centimeters, where a single milliohm of excess trace resistance causes a measurable efficiency penalty. TA is operating ambient temperature. JA is the junction to ambient thermal resistance. PCB Layout Guidelines Careful PCB layout is critical to achieving low switching losses and clean, stable operation. Use the following guidelines for good PCB layout: Keep the input capacitors as close as possible to the IN and PGND pins. Keep the output capacitors as close as possible to the OUT and PGND pins. Layout Recommendation PGND IN 29 OUT 27 26 25 24 23 22 1 21 2 20 EP1 3 SGND 28 EP2 4 EP3 5 19 18 6 17 7 16 8 9 10 PGND www.maximintegrated.com 11 12 13 PGND OUT 14 15 OUT Maxim Integrated 17 MAXM17503 4.5V to 60V, 2.5A High-Efficiency, DC-DC Step-Down Power Module with Integrated Inductor Chip Information Package Information PROCESS: BiCMOS For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages. Note that a "+", "#", or "-" in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. Ordering Information PART TEMP RANGE MAXM17503ALJ+T -40C to +125C MSL PINPACKAGE 3 29 SiP +Denotes a lead(Pb)-free/RoHS-compliant package. T = Tape and reel. www.maximintegrated.com PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO. 29 SiP L32915+1 21-0879 90-0459 Maxim Integrated 18 MAXM17503 4.5V to 60V, 2.5A High-Efficiency, DC-DC Step-Down Power Module with Integrated Inductor Revision History REVISION NUMBER REVISION DATE PAGES CHANGED 0 11/14 Initial release 1 4/15 Added application information to avoid potential latch-up issue on EN pin and added MSL 3 rating 11, 18 2 11/16 Updated Package Thermal Characteristics and notes sections, updated Pin 4 in the Pin Description section, and updated the Loop Compensation section 2, 11, 15 DESCRIPTION -- For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated's website at www.maximintegrated.com. Maxim Integrated cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim Integrated product. No circuit patent licenses are implied. Maxim Integrated reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance. Maxim Integrated and the Maxim Integrated logo are trademarks of Maxim Integrated Products, Inc. (c) 2016 Maxim Integrated Products, Inc. 19 Mouser Electronics Authorized Distributor Click to View Pricing, Inventory, Delivery & Lifecycle Information: Maxim Integrated: MAXM17503ALJ+ MAXM17503ALJ+T