LT8711 Micropower Synchronous Multitopology Controller with 42V Input Capability FEATURES DESCRIPTION n Easily Configurable as a Synchronous Buck, Boost, The LT 8711 is a multitopology current mode PWM control- SEPIC, ZETA or Nonsynchronous Buck-Boost Converter ler that can easily be configured as a synchronous buck, n Wide Input Range: 4.5V to 42V (V Can Operate boost, SEPIC, ZETA or as a nonsynchronous buck-boost IN to 0V, when EXTV > 4.5V) converter. Its dual gate drive voltage inputs optimize gate CC n Automatic Low Noise Burst Mode Operation driver efficiency. n Low I in Burst Mode Operation (15A Operating) Q The 15A no-load quiescent current with the output voltage n Input Voltage Regulation for High Impedance Source in regulation extends operating run time in battery powered n 100% Duty Cycle in Dropout (Buck Mode) systems. Low ripple Burst Mode operation enables high n 2A Gate Drivers (BG and TG) efficiency at very light loads while maintaining low output n Adjustable Soft-Start with One Capacitor voltage ripple. The LT8711 s fixed switching frequency can n Frequency Programmable from 100kHz to 750kHz be set from 100kHz to 750kHz or can be synchronized to n Can Be Synchronized to External Clock an external clock. n Available in 20-Lead TSSOP and 20-Lead 3mm4mm The additional features include 100% duty cycle capability QFN Packages when in buck mode, a topology selection pin and adjustable soft-start. LT8711 is available in the 20-lead TSSOP and APPLICATIONS 20-lead 3mm4mm QFN packages. All registered trademarks and trademarks are the property of their respective owners. n General Purpose DC/DC Conversion n Automotive Systems n Industrial Supplies n Solar Panel Power Converter TYPICAL APPLICATION 400kHz 5V to 40V Input/12V Output Nonsynchronous Buck Boost V IN Efficiency vs Load Current 5V TO 40V 10F 6 100 V BIAS IN 50V, X7R 2.2F EN/FBIN 90 V EXTV INTV CC EE OUT 80 100pF LT8711 TG M1 70 OPMODE V 2.2F L1 OUT 60 D1 D2 12V, 4.7H INTV CC 3.5A (V >16V) ISN IN 50 2.5A (9V < V < 16V) IN 60.4k 4m 1.5A (V < 9V) 40 IN RT 1M 100F 2 SYNC 30 ISP V = 5V 330nF 16V, X7R IN GND M2 20 69.8k V = 12V IN SS V = 24V IN 100pF BG 10 V = 36V IN CSP 0 4m 0.001 0.01 0.1 1 4 2.2nF CSN 110k LOAD CURRENT (A) V C 8711 TA01b FB 8711 TA01a Rev A 1 Document Feedback For more information www.analog.com EFFICIENCY (%)LT8711 ABSOLUTE MAXIMUM RATINGS (Note 1) V Voltage ................................................ 0.3V to 42V CSN Voltage ........................... CSP 0.3V to CSP+0.3V IN BIAS Voltage .............................................. 0.3V to 42V ISP Voltage .............................. ISN 0.3V to ISN + 0.3V EXTV Voltage ......................................... 0.3V to 42V ISN Voltage ...............................................0.3V to BIAS CC BG, TG Voltage .....................................................Note 2 INTV Voltage ......................................... 0.3V to 5.5V CC FB Voltage ................................................. 0.3V to 5.5V RT Voltage ................................................ 0.3V to 5.5V V Voltage ................................................ 0.3V to 2.5V SS Voltage ............................................... 0.3V to 5.5V C EN/FBIN Voltage ................. 0.3V to MAX(V , EXTV ) Operating Junction Temperature Range IN CC SYNC Voltage ........................................... 0.3V to 5.5V LT8711E ............................................. 40C to 125C OPMODE Voltage ...................................... 0.3V to 5.5V LT8711I .............................................. 40C to 125C INTV Voltage..................................................... Note 2 Storage Temperature Range .................. 65C to 150C EE CSP Voltage ............................................... 0.3V to 42V Lead Temperature (Soldering, 10 sec) ...................300C PIN CONFIGURATION TOP VIEW TOP VIEW EN/FBIN 1 20 RT FB 2 19 SYNC 20 19 18 17 V 3 18 NC C V 1 16 CSP C SS 4 17 CSP SS 2 15 CSN OPMODE 5 16 CSN 21 OPMODE EXTV 3 14 CC 21 GND ISP 6 15 EXTV CC GND ISP 4 13 V IN ISN 7 14 V IN ISN 5 12 INTV CC INTV 8 13 INTV EE CC INTV 6 11 NC EE BIAS 9 12 NC 7 8 9 10 TG 10 11 BG FE PACKAGE UDC PACKAGE 20-LEAD PLASTIC TSSOP 20-LEAD (3mm 4mm) PLASTIC QFN T = 125C, = 38C/W, = 10C/W JMAX JA JC T = 125C, = 52C/W, = 6.8C/W EXPOSED PAD (PIN 21) IS GND, MUST BE SOLDERED TO PCB JMAX JA JC EXPOSED PAD (PIN 21) IS GND, MUST BE SOLDERED TO PCB ORDER INFORMATION