LT3692 Monolithic Dual Tracking 3.5A Step-Down Switching Regulator Fea T Descrip T n Wide Input Range: The LT 3692 is a dual current mode PWM step-down Operation from 3V to 36V DC/DC converter with two internal 3.8A switches. Indepen- OVLO Protects Circuit Through 60V Transients dent input voltage, shutdown, feedback, soft-start, current n Independent Supply, Shutdown, Soft-Start, limit and comparator pins for each channel simplify com- Programmable Current Limit and Programmable plex power supply tracking and sequencing requirements. Power Good for Each 3.5A Regulator To optimize efficiency and component size, both convert- n Die Temperature Monitor ers have a programmable maximum current limit and are n Adjustable/Synchronizable Fixed Frequency synchronized to either a common external clock input, Operation from 250kHz to 2.25MHz with or a resistor settable fixed 250kHz to 2.25MHz internal Synchronized Clock Output oscillator. A frequency divider is provided for channel 1 n Independent Synchronized Switching Frequencies to further optimize component size. At all frequencies, a Optimize Component Size 180 phase relationship between channels is maintained, n Antiphase Switching reducing voltage ripple and component size. A clock output n Outputs Can Be Paralleled is available for synchronizing multiple regulators. n Flexible Output Voltage Tracking n Minimum input to output voltage ratios are improved by Enhanced Short-Circuit Protection n allowing the switch to stay on through multiple clock cycles Low Dropout: 95% Maximum Duty Cycle n only switching off when the boost capacitor needs recharg- 5mm 5mm QFN Package ing. Independent channel operation can be programmed a T using the SHDN pin. Disabling both converters reduces the total quiescent to <10A. n Automotive Supplies L, LT, LTC, LTM, Burst Mode, Linear Technology and the Linear logo are registered trademarks n Distributed Supply Regulation of Linear Technology Corporation. All other trademarks are the property of their respective owners. Independent Synchronized Switching Frequencies Typical a T Extend Full Frequency Input Range Dual 1.8V/3.5A and 5V/3.5A Step-Down Converter CLKOUT V IN 6V TO 32V 4.7F 2 SW1 V V IN1 IN2 SHDN1 SHDN2 BST1 BST2 V SW1 SW2 OUT2 SW2 6.8H 6.8H 0.47F 1F IND1 IND2 V OUT1 LT3692 3692 TA01b V OUT2 V = 12V 1s/DIV IN 1.8V 3.5A 5V 3.5A V V OUT1 OUT2 500kHz/ 500kHz 100F 47F 250kHz 10k FB1 FB2 42.2k 100k 8.06k 8.06k 2 CMPI1 CMPI2 143k CLKOUT CMPO1 CMPO2 PG2 SS2 SS1 SS2 7.15k 60.4k ILIM2 ILIM1 ILIM2 SW1 CLOCKOUT DIV CLKOUT 60.4k 500kHz V 60.4k V C2 C1 680pF RT/SYNC T 330pF J GND 33pF 0.1F SW2 36.5k 47pF 17.8k 13.0k 0.1F 3692 TA01a 3692 TA01c V = 24V 1s/DIV IN 3692fa 1 For more information www.linear.com/3692 ion pplica ions pplica ion uresLT3692 a Te Maxi Mu M r a T p in c F T (Note 1) TOP VIEW V , SHDN1/2, CMPO1/2 ............................ 40V/0.3V IN1/2 V Transient (Note 2) ................................ 60V/0.3V IN1/2 32 31 30 29 28 27 26 25 SW1/2 ....................................................................V IN1/2 BST1 1 24 ILIM1 BST1/2 ........................................................... 60V/0.3V CMPO1 2 23 V C1 BST1/2 Pin Above SW1/2 ..........................................25V CMPI1 RT/SYNC 3 22 IND1/2, V .........................................40V/0.3V, 7A OUT1/2 FB1 4 21 CLKOUT 33 FB1/2, CMPI1/2, SS1/2 ................................................5V GND FB2 5 20 T J RT/SYNC .....................................................................5V CMPI2 6 19 DIV DIV, ILIM1/2 .............................................................2.5V CMPO2 7 18 V C2 BST2 8 17 ILIM2 V , T .............................................................. 100A C1/2 J 9 10 11 12 13 14 15 16 Operating Junction Temperature Range (Note 3) LT3692EUH ........................................ 40C to 125C LT3692IUH ......................................... 40C to 125C UH PACKAGE 32-LEAD (5mm 5mm) PLASTIC QFN Storage Temperature Range .................. 65C to 150C = 35C/W JA EXPOSED PAD (PIN 33) IS GND, MUST BE SOLDERED TO PCB *DO NOT CONNECT o r Der i n F Ma T LEAD FREE FINISH TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION TEMPERATURE RANGE LT3692EUH PBF LT3692EUH TRPBF 3692 32-Lead (5mm 5mm) Plastic QFN 40C to 125C LT3692IUH PBF LT3692IUH TRPBF 3692 32-Lead (5mm 5mm) Plastic QFN 40C to 125C Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container. Consult LTC Marketing for information on non-standard lead based finish parts. For more information on lead free part marking, go to: