EVALUATION KIT AVAILABLE MAX15462 42V, 300mA, Ultra-Small, High-Efficiency, Synchronous Step-Down DC-DC Converters General Description Benefits and Features The MAX15462 high-efficiency, high-voltage, synchronous Eliminates External Components and Reduces step-down DC-DC converter with integrated MOSFETs Total Cost operates over a 4.5V to 42V input voltage range. The No SchottkySynchronous Operation for High converter delivers output current up to 300mA at 3.3V Efficiency and Reduced Cost (MAX15462A), 5V (MAX15462B), and adjustable output Internal Compensation Internal Feedback Divider for Fixed 3.3V, 5V voltages (MAX15462C). The device operates over the -40C to +125C temperature range and is available in a Output Voltages Internal Soft-Start compact 8-pin (2mm x 2mm) TDFN package. Simulation models are available. All-Ceramic Capacitors, Ultra-Compact Layout The device employs a peak-current-mode control architec- Reduces Number of DC-DC Regulators to Stock Wide 4.5V to 42V Input Voltage Range ture with a MODE pin that can be used to operate the Fixed 3.3V and 5V Output Voltage Options device in the pulse-width modulation (PWM) or pulse- Adjustable 0.9V to 0.89 x V Output Voltage Option frequency modulation (PFM) control schemes. PWM oper- IN Delivers Up to 300mA Load Current ation provides constant frequency operation at all loads Configurable Between PFM and Forced-PWM and is useful in applications sensitive to variable switch- Modes ing frequency. PFM operation disables negative inductor current and additionally skips pulses at light loads for high Reduces Power Dissipation efficiency. The low-resistance on-chip MOSFETs ensure Peak Efficiency = 92% high efficiency at full load and simplify the PCB layout. PFM Feature for High Light-Load Efficiency Shutdown Current = 2.2A (typ) To reduce input inrush current, the device offers an internal soft-start. The device also incorporates an EN/ Operates Reliably in Adverse Industrial Environments UVLO pin that allows the user to turn on the part at the Hiccup-Mode Current Limit and Autoretry Startup desired input-voltage level. An open-drain RESET pin can Built-In Output Voltage Monitoring with Open-Drain be used for output-voltage monitoring. RESET Pin Programmable EN/UVLO Threshold Applications Monotonic Startup into Prebiased Output Process Control Overtemperature Protection Industrial Sensors -40C to +125C Automotive/Industrial 420mA Current Loops Temperature Range HVAC and Building Control High-Voltage LDO Replacement Typical Operating Circuit General-Purpose Point of Load L1 33H V V OUT IN Ordering Information appears at end of data sheet. 3.3V, 4.5V TO V LX IN C IN C 300mA 42V OUT 1F 10F EN/UVLO GND MAX15462A V CC RESET C VCC 1F MODE V OUT 19-7552 Rev 0 3/15MAX15462 42V, 300mA, Ultra-Small, High-Efficiency, Synchronous Step-Down DC-DC Converters Absolute Maximum Ratings V to GND ............................................................-0.3V to +48V Continuous Power Dissipation (T = +70C) IN A EN/UVLO to GND..................................................-0.3V to +48V 8-Pin TDFN (derate 6.2mW/C above +70C) ............496mW LX to GND ....................................................-0.3V to V + 0.3V Operating Temperature Range ......................... -40C to +125C IN V , FB/V , RESET to GND .............................-0.3V to +6V Junction Temperature ......................................................+150C CC OUT MODE to GND .............................................-0.3V to V + 0.3V Storage Temperature Range ............................ -65C to +150C CC LX total RMS Current .....................................................800mA Soldering Temperature (reflow) .......................................+260C Output Short-Circuit Duration ....................................Continuous Lead Temperature (soldering, 10s) .................................+300C 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. (Note 1) Package Thermal Characteristics TDFN Junction-to-Ambient Thermal Resistance ( ) ......+162C/W JA Junction-to-Case Thermal Resistance ( ) .............+20C/W JC Note 1: 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.maximintegrated.com/thermal-tutorial. Electrical Characteristics (V = 24V, V = 0V, C = C = 1F, V = 1.5V, LX = MODE = RESET = unconnected T = T = -40C to +125C, unless IN GND IN VCC EN/UVLO A J otherwise noted. Typical values are at T = +25C. All voltages are referenced to GND, unless otherwise noted.) (Note 2) A PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS INPUT SUPPLY (V ) IN Input Voltage Range V 4.5 42 V IN Input Shutdown Current I V = 0V, shutdown mode 2.2 4 A IN-SH EN/UVLO MODE = unconnected, I 95 160 A Q-PFM FB/V = 1.03 x FB/V Input Supply Current OUT OUT-REG I Normal switching mode, V = 24V 2.5 4 mA Q-PWM IN ENABLE/UVLO (EN/UVLO) V V rising 1.19 1.215 1.24 ENR EN/UVLO EN/UVLO Threshold V V falling 1.06 1.09 1.15 V ENF EN/UVLO V V falling, true shutdown 0.75 EN-TRUESD EN/UVLO EN/UVLO Input Leakage Current I V = 42V, T = +25C -100 +100 nA EN/UVLO EN/UVLO A LDO (V ) CC V Output Voltage Range V 6V < V < 42V, 0mA < I < 10mA 4.75 5 5.25 V CC CC IN VCC V Current Limit I V = 4.3V, V = 12V 13 30 50 mA CC VCC-MAX CC IN V Dropout V V = 4.5V, I = 5mA 0.15 0.3 V CC CC-DO IN VCC V V rising 4.05 4.18 4.3 CC-UVR CC V UVLO V CC V V falling 3.7 3.8 3.95 CC-UVF CC Maxim Integrated 2 www.maximintegrated.com