EVALUATION KIT AVAILABLE 4A, Low-Noise, High-Frequency, MAX1709 Step-Up DC-DC Converter General Description Benefits and Features The MAX1709 sets a new standard of space savings Integration Reduces External Component Count to for high-power, step-up DC-DC conversion. It delivers Save Space up to 20W at a fixed (3.3V or 5V) or adjustable (2.5V to On-Chip 10A Power MOSFET 5.5V) output, using an on-chip power MOSFET from a 5V, 4A Output from a 3.3V Input +0.7V to +5V supply. Fixed 3.3V or 5V Output Voltage or Fixed-frequency PWM operation ensures that the Adjustable (2.5V to 5.5V) switching noise spectrum is constrained to the 600kHz Input Voltage Range Down to 0.7V fundamental and its harmonics, allowing easy postfilter- Constant Frequency Reduces Post-Filtering ing for noise reduction. External clock synchronization Low-Noise, Constant-Frequency Operation capability allows for even tighter noise spectrum con- (600kHz) trol. Quiescent power consumption is less than 1mW to extend operating time in battery-powered systems. Synchronizable Switching Frequency (350kHz to 1000kHz) Two control inputs (ONA, ONB) allow simple push-on, push-off control through a single momentary pushbut- Lower Power Consumption Extends Battery Life ton switch, as well as conventional on/off logic control. 1mW Quiescent Power The MAX1709 also features programmable soft-start and current limit for design flexibility and optimum per- formance with batteries. Ordering Information The MAX1709 is supplied in both a high-power TSSOP package, which allows a 10A switch current and a RMS PART TEMP RANGE PIN-PACKAGE 4A output, and a narrow SO package, which supplies a MAX1709ESE -40C to +85C 16 Narrow SO 2.4A output with a switch rated at 6A . Although the RMS MAX1709EUI+ -40C to +85C 28 TSSOP-EP* narrow SO device has a lower RMS switch rating, it has +Denotes a lead(Pb)-free/RoHS-compliant package. the same peak switch current rating as the TSSOP *EP = Exposed pad. device, and so can supply 4A loads intermittently. If loads of 2A or less are required, refer to the MAX1708. Applications Pin Configuration Routers, Servers, Workstations, Card Racks TOP VIEW Local 2.5V to 3.3V or 5V Conversion ONA 1 28 ONB Local 3.3V to 5V Conversion LX 2 27 CLK 3.6V or 5V RF PAs in Communications Handsets LX 3 26 3.3/5 LX 4 25 NC MAX1709 Typical Operating Circuit LX 5 24 NC INPUT 1V TO 5V LX 6 23 PGND LX 7 22 PGND 1H LX 8 21 PGND OUTPUT OFF ON 3.3V, 5V, NC 9 20 PGND ONA LX OR ADJ NC 10 19 PGND MAX1709 UP TO 4A SYNC OR CLK GND 11 18 PGND GND INTERNAL SS/ILM 12 17 NC SS/LIM REF 13 16 FB REF OUT GND 14 15 OUT TSSOP-EP 19-1724 Rev 3 2/154A, Low-Noise, High-Frequency, MAX1709 Step-Up DC-DC Converter Absolute Maximum Ratings ONA, ONB, OUT, SS/LIM, 3.3/5 to GND ...............-0.3V to +6.0V 28-Pin TSSOP Exposed Pad Junction-to-Exposed Pad Thermal Resistance......................................1.2C/W LX to PGND ...........................................................-0.3V to +6.0V FB, CLK, REF to GND.............................. -0.3V to (V + 0.3V) Operating Temperature Range ...........................-40C to +85C OUT Junction Temperature......................................................+150C PGND to GND .......................................................-0.3V to +0.3V Storage Temperature Range .............................-65C to +150C Continuous Power Dissipation (T = +70C) A 16-Pin Narrow SO (derate 16.5mW/C above +70C) .....1.3W Lead Temperature (soldering, 10s) .................................+300C 28-Pin TSSOP Exposed Pad (derate 23.8mW/C above +70C)...................................1.9W 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 = +3.6V, ONA = ONB = FB = GND, T = 0C to +85C, unless otherwise noted. Typical values are at T = +25C.) OUT CLK A A PARAMETER CONDITIONS MIN TYP MAX UNITS 3.3/5 = GND, I = 1A 3.26 3.34 3.42 SW Output Voltage V < 0.1V (Note 1) V FB 3.3/5 = OUT, I = 1A 4.92 5.05 5.17 SW Load Regulation Measured between 1A < I < 3A (Note 2) -0.25 -0.45 %/A SW FB Regulation Voltage I = 1A 1.215 1.240 1.265 V SW FB Input Current V = +1.5V 1 200 nA FB Output Voltage Adjust Range 2.5 5.5 V Output Undervoltage Lockout (Note 3) 2.0 2.3 V Frequency in Startup Mode V =1.5V 40 400 kHz OUT Minimum Startup Voltage I < 1mA (Note 1), T = +25C (Note 4) 0.9 1.1 V OUT A Minimum Operating Voltage (Note 5) 0.7 V Soft-Start Pin Current V = 1V 3.2 4 5.0 A SS/LIM OUT Supply Current V = 1.5V (Note 6) 200 440 A FB OUT Leakage Current In V = 3.6V 0.1 5 A ONB Shutdown LX Leakage Current V = V = V = +5.5V 0.1 40 A LX ONB OUT n-Channel Switch 22 40 m On-Resistance 7.5 12 SS/LIM = open 9 n-Channel Current Limit A 3.5 6.5 SS/LIM = 150k to GND 5 MAX1709EUI+ 10 RMS Switch Current A RMS MAX1709ESE 6 Reference Voltage I = 0 1.245 1.260 1.275 V REF Reference Load Regulation -1A < I < 50A 4 10 mV REF Reference Supply Rejection +2.5V < V < +5.5V 0.2 5 mV OUT 0.2 ONA, ONB, 3.3/5, 1.2V < V < 5.5V OUT V OUT Input Low Level (Note 7) V 0.2 CLK, 2.7V < V < 5.5V OUT V OUT www.maximintegrated.com Maxim Integrated 2