LT8631 100V, 1A Synchronous Micropower Step-Down Regulator FEATURES DESCRIPTION n Ultrawide Input Voltage Range: 3V to 100V The LT 8631 is a current mode PWM step-down DC/DC n Output Voltage Range: 0.8V to 60V converter with internal synchronous switches that provide n Internal Synchronous Switches current for output loads up to 1A. The wide input range n Low Ripple Burst Mode Operation: of 3V to 100V makes the LT8631 suitable for regulating 16A I at 12V to 5V Output Ripple <10mV power from a wide variety of sources, including automotive Q IN OUT P-P 7A I at 48V to 5V Output Ripple <10mV and industrial systems and 36V to 72V telecom supplies. Q IN OUT P-P n Low Dropout: 99% Maximum Duty Cycle Low ripple Burst Mode operation enables high efficiency n Peak Current Mode Control operation down to very low output currents while keeping n Fixed Frequency Operation: 100kHz to 1MHz the output ripple below 10mV . Resistor programmable P-P n Synchronization Input 100kHz to 1MHz frequency range and synchronization ca- n Programmable Undervoltage Lockout pability enable optimization between efficiency and external n Power Good Flag component size. The soft-start feature controls the ramp n Flexible Output Voltage Tracking rate of the output voltage, eliminating input current surge n Short-Circuit Protection during start-up, while also providing output tracking. A n Low Shutdown Current: 5A power good flag signals when the output voltage is within n Tolerates Pin Open/Short Faults 7.5% of the regulated output. Undervoltage lockout can n Thermally Enhanced 20-Lead TSSOP with High be programmed using the EN/UV pin. Shutdown mode Voltage Lead Spacing reduces the total quiescent current to < 5A. The LT8631 is available in a 20-lead TSSOP package with exposed pad for low thermal resistance and high voltage lead spacing. APPLICATIONS L, LT, LTC, LTM, Linear Technology, Burst Mode and the Linear logo are registered trademarks n Automotive Supplies of Analog Devices, Inc. All other trademarks are the property of their respective owners. n Telecom Supplies n Distributed Supply Regulation TYPICAL APPLICATION 5V, 1A Step-Down Converter Efficiency vs Load Current 95 V IN F = 400kHz SW V BST IN 6.5V TO 100V 90 LT8631 0.1F 22H 2.2F EN/UV SW 85 80 PG 75 IND 70 V OUT INTV V CC OUT 65 5V, 1A 2.2F 4.7pF 1M 60 V = 12V IN RT FB 55 V = 24V IN V = 48V IN 191k 50 25.5k SYNC/MODE TR/SS 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 LOAD CURRENT (A) GND 8631 TA01b 47F 0.1F 8631 TA01a F = 400kHz SW 8631fb 1 For more information www.linear.com/LT8631 EFFICIENCY (%)LT8631 ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION (Note 1) V , EN/UV, PG ........................................................100V IN TOP VIEW IND, V , ...................................................... 60V/0.3V OUT V 1 20 SW IN SYNC/MODE ...............................................................6V FB, TR/SS ...................................................................4V 3 EN/UV 18 BST Operating Junction Temperature Range LT8631EFE (Note 2) ............................... 40C to 125C PG 5 16 INTV 21 CC GND NC 6 LT8631IFE (Note 2) ................................ 40C to 125C 15 NC SYNC/MODE 7 14 IND LT8631HFE (Note 2) ............................... 40C to 150C RT 8 13 NC Storage Temperature Range .................. 65C to 150C NC 9 12 V OUT TR/SS 10 11 FB FE PACKAGE VARIATION FE20(16) 20-LEAD PLASTIC TSSOP = 40C/W, = 10C/W JA JC(PAD) EXPOSED PAD (PIN 21) IS GND, MUST BE SOLDERED TO PCB