LTC7840 2-Phase Dual Output Nonsynchronous Boost Controller with Hiccup Mode FEATURES DESCRIPTION n Wide V Range: 5.5V to 60V The LTC 7840 is a dual phase dual output, constant fre- IN n Configurable for Dual Phase Single/Dual Output quency current mode, nonsynchronous boost controller Operation that drives N-channel power MOSFETs. The nonsynchro- n Peak Current Mode Control with Smooth Quadratic nous topology makes the output voltage dependent on Slope Compensation and Dynamic Slope Recovery the choice of external components. n Adjustable Max Duty Cycle A wide 5.5V to 60V input supply range can accommodate n Adjustable Min On-Time high input voltage surges. The LTC7840 can be config- n Hiccup Mode for Overcurrent Protection ured as a dual phase single output or dual output control- n Adjustable Current Sense Limit ler. It can be also configured for the SEPIC and flyback n Output Overvoltage Protection topologies. The switching frequency is programmed by n Programmable and Phase-Lockable Operating the voltage on the FREQ pin or synchronized to an external Frequency (from 50kHz to 425kHz) clock. The LTC7840 features a precise 1.2V internal refer- n Adjustable Soft-Start Current Ramping ence. It has two RUN pins and two power good output n 1% Internal Voltage Reference indicators. n Internal 10V LDO Regulator for Gate Driver n The LTC7840 has an internal 10V LDO with undervoltage Two RUN Pins and Dual Power Good Monitors n lockout protection for its on-chip gate driver. The maxi- Flexible Topology for Boost, SEPIC and Flyback mum duty cycle and blanking time can be programmed by the voltage on D and BLANK pins, respectively. The MAX hiccup mode protects the system in the event of faults. APPLICATIONS The LTC7840 is available in a 28-lead thermally enhanced n Automotive System, Telecom System and Industrial TSSOP package (FE28) or a 28-lead QFN package (UFD28). Power Supplies All registered trademarks and trademarks are the property of their respective owners. TYPICAL APPLICATION 10H Efficiency vs Output Current V IN V OUT1 94 12V 48V 33F V = 240V OUT 84.5k Efficiency vs Output Current 92 12.1k 63V 475k RUN1 V GATE1 IN 90 PINS NOT SHOWN: 66F + VFB1 SENSE1 CLKOUT, 88 80V SYNC, FREQ 86 12.1k ILIM1 2m SS1 PGOOD2 73.2k 0.1F 84 SENSE1 82 INTV BLANK CC 100H 100pF 1nF DMAX 80 SGND ITH1 78 LTC7840 SS2 DRV CC 15k 33nF V 2.2F 10F OUT 76 240V PGND V = 24V IN 74 0.7A V = 12V IN GATE2 72 V = 9V IN 100pF 200F + SENSE2 70 400V ITH2 0 0.2 0.4 0.6 0.8 1.0 1.2 ILIM2 8m I (A) 46.4k OUT 47nF 7840 TA01b VFB2 RUN2 PGOOD1 SENSE2 11.8k 2.37M 7840 TA01a Rev 0 1 Document Feedback For more information www.analog.com EFFICIENCY (%)LTC7840 ABSOLUTE MAXIMUM RATINGS (Notes 1, 2) Input Supply Voltage (V ) ......................... 0.3V to 65V ILIM1, ILIM2 Voltage .............................0.3V to INTV IN CC RUN1, RUN2 Voltage .................................... 0.3V to 6V FREQ, SYNC Voltage .............................0.3V to INTV CC + + SENSE1 , SENSE2 Voltage ...................0.3V to INTV DRV Peak Output Current ................................100mA CC CC D , BLANK Voltage ...........................0.3V to INTV Operating Junction Temperature Range (Note 3) MAX CC PGOOD1, PGOOD2 Voltage .......................... 0.3V to 6V LTC7840E .......................................... 40C to 125C VFB1, VFB2 Voltage ..............................0.3V to INTV LTC7840I ........................................... 40C to 125C CC SS1, SS2 Voltage ..................................0.3V to INTV LTC7840H .......................................... 40C to 150C CC ITH1, ITH2 Voltage ................................0.3V to INTV Storage Temperature Range .................. 65C to 150C CC Reflow Peak Body Temperature ............................260C PIN CONFIGURATION TOP VIEW TOP VIEW + BLANK 1 28 SENSE1 CLKOUT 2 27 SENSE1 SYNC 3 26 ILIM1 28 27 26 25 24 23 DMAX 4 25 INTV CC DMAX 1 22 INTV CC FREQ 5 24 SGND FREQ 2 21 SGND SS1 6 23 V SS1 3 20 V IN IN VFB1 4 19 VFB1 7 22 DRV DRV CC 29 CC 29 SGND SGND ITH1 5 18 GATE1 ITH1 8 21 GATE1 RUN1 6 17 PGND RUN1 9 20 PGND RUN2 7 16 GATE2 RUN2 10 19 GATE2 SS2 8 15 PGOOD1 SS2 11 18 PGOOD1 9 10 11 12 13 14 VFB2 12 17 PGOOD2 ITH2 13 16 ILIM2 + SENSE2 14 15 SENSE2 UFD PACKAGE FE PACKAGE 28-LEAD (4mm 5mm) PLASTIC QFN 28-LEAD PLASTIC TSSOP T = 150C, = 47C/W JMAX JA T = 150C, = 30C/W JMAX JA EXPOSED PAD (PIN 29) IS SGND, MUST BE SOLDERED TO PCB EXPOSED PAD (PIN 29) IS SGND, MUST BE SOLDERED TO PCB Rev 0 2 For more information www.analog.com VFB2 SYNC ITH2 CLKOUT + SENSE2 BLANK SENSE2 SENSE1+ ILIM2 SENSE1 PGOOD2 ILIM1