LTC7149 60V, 4A Synchronous Step-Down Regulator for Inverting Outputs FEATURES DESCRIPTION n Wide V Range: 3.4V to 60V The LTC 7149 is a high efficiency 60V, 4A synchronous IN n Wide V Range: 0V to 28V monolithic step-down regulator for inverting output OUT n Single Resistor V Programming applications. The regulator features a single resistor- OUT n Integrated 110m Top N-Channel/50m Bottom programmable output voltage and high efficiency over a N-Channel MOSFETs wide V range. OUT n Regulated I : 440A, Shutdown I : 15A Q Q The inverting regulator operates from an input voltage n Board GND Referenced I/O Pins (RUN, PGOOD, range of 3.4V to 60V and provides an adjustable output MODE/SYNC) from (28V) to zero volts while delivering up to 4A of n Accurate Resistor Programmable inductor current. The switching frequency is also set Frequency (300kHz to 3MHz) with 50% with an external resistor. A user-selectable mode input is Frequency SyncRange provided to allow the user to trade off ripple noise for ef- n 92% Efficiency with 12 V and 5V IN OUT ficiency at light loads Burst Mode operation provides the n 0.8% Output Voltage Accuracy highest efficiency at light loads, while forced continuous n Peak Current Mode Operation mode provides low output ripple. The MODE/SYNC pin n Burst Mode Operation, Forced Continuous Mode can also be used to synchronize the switching frequency n Programmable Soft-Start to an external clock. Internal level-shift circuits allow the n Overtemperature Protection I/O pins (RUN, MODE/SYNC, PGOOD) to be referenced n Available in 28-Lead (4mm x 5mm) QFN and to board GND. TSSOPPackages The LTC7149 operates with a peak current mode architec- ture that allows for fast transient response with inherent APPLICATIONS cycle-to-cycle current limit protection. n Industrial Applications All registered trademarks and trademarks are the property of their respective owners. Protected n Telecom Power Supplies by U.S. Patents, including 5481178, 5705919, 5847554, 6580258. n Distributed Power Systems TYPICAL APPLICATION Efficiency with V = 5V OUT Efciency with V = 5V OUT 0.1F 100 6.8H V 95 IN RUN BOOST SW + 24V V V IN OUTSNS 150F 90 22F 22F 2 0.1F V OUT GND LTC7149 V OUT 5V 85 ITH 3.3A SV OUT INTV 80 CC 1k ISET MODE/SYNC R T 100pF 2.2F 75 V = 12V IN 4.7nF 100k 200k 10nF V = 24V IN 70 0 0.5 1 1.5 2 2.5 3 3.5 4 7149 TA01 f = 500kHz SW I (A) OUT 7149 TA01b 7149fa 1 For more information www.linear.com/LTC7149 EFFICIENCY (%)LTC7149 ABSOLUTE MAXIMUM RATINGS (Note 1) R , PGDFB, ITH, V .....INTV +0.3V to (SV 0.3V) V Voltage* (Note 3) ................................ 64V to 0.3V T INREG CC OUT IN EXTV Voltage* ....................................... 28V to 0.3V ISET Voltage* ............................................. V to 0.3V CC IN Operating Junction GND Voltage* ............................................. 28V to 0.3V Temperature Range (Notes 4, 6) ........ 40C to 125C RUN Voltage* .....................................64V to GND 0.3V Storage Temperature Range .................. 65C to 125C MODE/SYNC, PGOOD Voltage* ..GND + 6V to GND 0.3V *All voltage referenced to V , unless otherwise specified. V Voltage*....................................... V to 0.3V OUT OUTSNS IN PIN CONFIGURATION TOP VIEW TOP VIEW V 1 28 SW OUT 2 SW V 27 OUT 28 27 26 25 24 23 3 26 SW V OUT 1 22 V SW OUT V 4 25 SW OUT V 2 21 SW OUT V 5 24 SW OUT V 3 20 SW IN 6 SW V 23 IN V 4 19 SW 29 IN 7 22 SW V SV IN 29 OUT RUN 5 18 BOOST SV OUT RUN 8 21 BOOST 6 17 GND INTV CC 9 INTV GND 20 CC MODE/SYNC 7 16 EXTV CC 10 19 EXTV MODE/SYNC CC PGOOD 8 15 ITH PGOOD 11 18 ITH 9 10 11 12 13 14 PGDFB 12 17 ISET SV 13 V 16 OUT OUTSNS V 14 15 R INREG T UFD PACKAGE 28-LEAD (4mm 5mm) PLASTIC QFN FE PACKAGE 28-LEAD PLASTIC TSSOP T = 125C, = 43C/W, = 3.4C/W JMAX JA JC T = 125C, = 30C/W, = 5C to 10C/W JMAX JA JC EXPOSED PAD (PIN 29) IS SV , MUST BE SOLDERED TO PCB OUT EXPOSED PAD (PIN 29) IS SV , MUST BE SOLDERED TO PCB OUT