POWER LOSS (W) LT8705 80V V and V IN OUT Synchronous 4-Switch Buck- Boost DC/DC Controller Fea T Descrip T n Single Inductor Allows V Above, Below, or Equal The LT 8705 is a high performance buck-boost switch- IN ing regulator controller that operates from input voltages to Regulated V OUT n above, below or equal to the output voltage. The part has V Range 2.8V (Need EXTV > 6.4V) to 80V IN CC n integrated input current, input voltage, output current V Range: 1.3V to 80V OUT n and output voltage feedback loops. With a wide 2.8V to Quad N-Channel MOSFET Gate Drivers n 80V input and 1.3V to 80V output range, the LT8705 is Synchronous Rectification: Up to 98% Efficiency compatible with most solar, automotive, telecom and n Input and Output Current Monitor Pins battery-powered systems. n Synchronizable Fixed Frequency: 100kHz to 400kHz n Integrated Input Current, Input Voltage, Output Cur- The LT8705 includes servo pins to indicate which feedback rent and Output Voltage Feedback Loops loops are active. The MODE pin selects among Burst Mode n Clock Output Usable To Monitor Die Temperature operation, discontinuous or continuous conduction mode n Available in 38-Lead (5mm 7mm) QFN and TSSOP at light loads. Additional features include a 3.3V/12mA Packages with the TSSOP Modified for Improved LDO, a synchronizable fixed operating frequency, onboard High Voltage Operation gate drivers, adjustable UVLO, along with input and output current monitoring with programmable maximum levels. a T L, LT, LTC, LTM, Linear Technology, Burst Mode, Module and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their n High Voltage Buck-Boost Converters respective owners. n Input or Output Current Limited Converters Typical a T Telecom Voltage Stabilizer M1 V 22H V OUT IN M4 2 48V 36V TO + + 80V 5A 4.7F 220F M3 4.7F 220F M2 4 2 2 6 2 TO TO DIODE DIODE 1nF 10 0.22F 0.22F 10m 2 10 1nF 2 2 392k Efficiency and Power Loss 2 100 6 TG1 BOOST1 SW1 BG1 CSP CSN GND BG2 SW2 BOOST2 TG2 CSNIN CSPOUT 5 CSPIN CSNOUT 95 V EXTV IN CC 4 SHDN FBOUT 100k SWEN INTV 10k 90 3 CC LDO33 GATEV CC 4.7F LT8705 2 MODE SRVO FBIN 4.7F 85 FBIN SRVO FBOUT 1 4 V = 48V RT SRVO IIN OUT I = 2A LOAD 71.5k SS SRVO IOUT 80 0 30 40 50 60 70 80 IMON IN 1F V (V) 8705 TA01b TO TO IN IMON OUT V C CLKOUT SYNC BOOST1 BOOST2 20k 215k 56.2k 202kHz 4.7F 1F 220pF 3.3nF 8705 TA01 8705ff 1 For more information www.linear.com/LT8705 EFFICIENCY (%) ion pplica ions pplica ion uresLT8705 a Te Maxi Mu M r a T (Note 1) V -V , V -V , CSNIN, CSPIN, CSPOUT, CSNOUT Voltage ..0.3V to 80V CSP CSN CSPIN CSNIN V -V ...................................... 0.3V to 0.3V V , EXTV Voltage .................................. 0.3V to 80V CSPOUT CSNOUT IN CC SS, CLKOUT, CSP, CSN Voltage ................... 0.3V to 3V SW1, SW2 Voltage ......................................81V (Note 7) V Voltage (Note 2) ................................... 0.3V to 2.2V BOOST1, BOOST2 Voltage ......................... 0.3V to 87V C RT, LDO33, FBOUT Voltage .......................... 0.3V to 5V BG1, BG2, TG1, TG2 ........................................... (Note 6) IMON IN, IMON OUT Voltage ..................... 0.3V to 5V Operating Junction Temperature Range SYNC Voltage ............................................ 0.3V to 5.5V LT8705E (Notes 3, 8) ......................... 40C to 125C INTV , GATEV Voltage ............................ 0.3V to 7V LT8705I (Notes 3, 8) .......................... 40C to 125C CC CC V -V , V -V ..................... 0.3V to 7V LT8705H (Notes 3, 8)......................... 40C to 150C BOOST1 SW1 BOOST2 SW2 SWEN, MODE Voltage .................................. 0.3V to 7V LT8705MP (Notes 3, 8) ...................... 55C to 150C SRVO FBIN, SRVO FBOUT Voltage ........... 0.3V to 30V Storage Temperature Range .................. 65C to 150C SRVO IIN, SRVO IOUT Voltage ................. 0.3V to 30V Lead Temperature (Soldering, 10 sec) FBIN, SHDN Voltage ................................... 0.3V to 30V FE Package .......................................................300C p c F T TOP VIEW INTV 1 38 V IN CC TOP VIEW MODE 2 37 CSPIN IMON IN 3 36 CSNIN SHDN 4 38 37 36 35 34 33 32 CSN 5 34 CSPOUT SHDN 1 31 CSPOUT CSN 2 30 CSNOUT CSP 6 CSP EXTV 3 29 CC LDO33 7 32 CSNOUT LDO33 SRVO FBOUT 4 28 FBIN 8 FBIN 5 27 SRVO IOUT FBOUT 9 30 EXTV CC FBOUT 6 26 SRVO IIN 39 39 IMON OUT 10 GND GND IMON OUT 7 25 SRVO FBIN V 11 28 BOOST1 C V 8 24 NC C SS 12 SS BOOST1 9 23 CLKOUT 13 26 TG1 CLKOUT 10 22 TG1 SYNC 14 SYNC 11 21 SW1 RT 15 24 SW1 RT 12 20 NC GND 16 13 14 15 16 17 18 19 BG1 17 22 SW2 GATEV 18 21 TG2 CC BG2 19 20 BOOST2 UHF PACKAGE 38-LEAD (5mm 7mm) PLASTIC QFN FE PACKAGE T = 125C, = 34C/W VARIATION: FE38(31) JMAX JA EXPOSED PAD (PIN 39) IS GND, MUST BE SOLDERED TO PCB 38-LEAD PLASTIC TSSOP T = 125C, = 25C/W JMAX JA EXPOSED PAD (PIN 39) IS GND, MUST BE SOLDERED TO PCB 8705ff 2 For more information www.linear.com/LT8705 GND IMON IN BG1 MODE GATEV SWEN CC BG2 INTV CC BOOST2 V IN TG2 CSPIN SW2 CSNIN ion igura on in ings bsolu