LTC3802 Dual 550kHz Synchronous 2-Phase DC/DC Controller with Programmable Up/Down Tracking FEATURES DESCRIPTIO n Wide V Range: 3V to 30V Operation with Line The LTC 3802 is a dual switching regulator controller IN Feedforward Compensation optimized for high efficiency step-down conversion from n Leading Edge Modulation Architecture for input voltages between 3V to 30V. The controller uses a Extremely Low Duty Cycle Operation leading edge modulation scheme to allow extremely low n Phase-Lockable Fixed Frequency: 330kHz to 750kHz duty cycle operation. The constant frequency voltage mode n Two 180 Out-of-Phase Controllers controller allows a phase-lockable frequency between n Fast Programmable Power-Up/-Down Tracking 330kHz and 750kHz. Power loss and noise due to the ESR n Programmable Current Limit Without External of the input capacitors are minimized by operating the two Current Sense Resistor controller output stages 180 out of phase. The synchro- n Optional Burst Mode Operation at Light Load nous buck architecture automatically shifts to Burst Mode n 1% 0.6V Voltage Reference operation as the output load decreases, ensuring maxi- n External N-Channel MOSFET Architecture mum efficiency over a wide range of load currents. n Low Shutdown Current: <100m A The LTC3802 features an onboard, trimmed 0.6V refer- n Overvoltage Protection and PGOOD Flag ence and provides better than 1% regulation at the con- n Small 28-Lead SSOP and 32-Lead QFN Packages verter outputs. A separate output sense provides real time U overvoltage protection and PGOOD sensing. An FBT pin APPLICATIO S programs the power-up/-down tracking between the two n Notebook and Palmtop Computers channels to meet various sequencing requirements. A n Portable Instruments RUN/SS pin provides soft-start and externally program- n Battery-Operated Digital Devices mable current limit protection functions. n , LTC and LT are registered trademarks of Linear Technology Corporation. DC Power Distribution Systems Burst Mode is a registered trademark of Linear Technology Corporation. U.S. Patent Nos 5481178, 5846544, 6304066, 6580258, 5055767, 6307356 TYPICAL APPLICATIO V IN 5V TO 22V + 56F 4.7F 5V + 25V 25V CMDSH-3 2 CMDSH-3 10F 8 Si7860DP Si7860DP 2 2 PV TG1 TG2 CC 1H V 1H OUT1 V BOOST2 OUT2 3.3V 0.1F 0.1F 2.5V 15A BOOST1 SW2 15A B340B B340B Si7440DP SW1 BG2 2 10k 10k + 330F + 10k 10k 330F BG1 PLLIN 4V Si7440DP 4V PLLLPF PGND 3 2 47k 47k 3 LTC3802 I I MAX1 MAX2 560pF 3.16k 3.16k FBT CMPIN2 2.21k 2.21k CMPIN1 V 5V CC 2200pF 1500pF 10 + COMP1 COMP2 560pF 0.1F 10F 390 15k FB1 FB2 2200pF 1500pF 330pF SGND PHASEMD 15k 390 FCB V INFF RUN/SS PGOOD 330pF 3802 TA01 10k 0.1F V IN 5V 0.47F 3802f 1 U ULTC3802 ABSOLUTE AXI U RATI GS (Note 1) Supply Voltage Extended Commercial V , PV ............................................................. 7V Operating Temperature Range (Note 2) .. 40 C to 85 C CC CC BOOSTn.............................................................. 37V Storage Temperature Range BOOSTn SWn .................................................... 7V LTC3802EGN ................................... 65 C to 150 C SWn ........................................................ 1V to 30V LTC3802EUH ................................... 65 C to 125 C Input Voltage Lead Temperature (Soldering, 10 sec) V .................................................................... 30V LTC3802EGN Only ........................................... 300 C INFF FBn, CMPINn, FBT, PLLIN, FCB, RUN/SS, PGOOD, PLLLPF, PHASEMD, EXTREF, I n .......................... 0.3V to V + 0.3V MAX CC UUW PACKAGE/ORDER I FOR ATIO TOP VIEW TOP VIEW ORDER PART ORDER PART 1 BG2 PV 28 CC NUMBER NUMBER 2 BOOST2 BG1 27 LTC3802EGN LTC3802EUH 32 31 30 29 28 27 26 25 3 TG2 BOOST1 26 SW1 1 24 PGND 4 SW2 TG1 25 PGND 2 23 PGND 5 PLLIN SW1 24 PGND 3 22 PLLIN 6 PLLLPF PGND 23 I 4 21 PLLLPF MAX1 7 I I 22 33 MAX2 MAX1 FBT 5 20 I MAX2 8 CMPIN2 FBT 21 CMPIN1 6 19 CMPIN2 9 V CMPIN1 20 CC COMP1 7 18 V CC UH PART 10 COMP2 COMP1 19 FB1 8 17 COMP2 MARKING 11 FB2 FB1 18 9 10 11 12 13 14 15 16 12 PHASEMD SGND 17 3802 13 V FCB 16 INFF 14 PGOOD RUN/SS 15 UH PACKAGE 32-LEAD (5mm 5mm) PLASTIC QFN GN PACKAGE 28-LEAD PLASTIC SSOP T = 125 C, q = 34 C/W JMAX JA T = 125 C, q = 110 C/W EXPOSED PAD (PIN 33) IS GND JMAX JA MUST BE SOLDERED TO PCB Consult LTC Marketing for parts specified with wider operating temperature ranges. ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range. (Note 3) V = PV = BOOST = 5V, unless otherwise specified. CC CC SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS V V Supply Voltage l 356 V CC CC PV PV Supply Voltage (Note 4) l 56 V CC CC BV BOOST Pin Voltage V V (Note 4) l 56 V CC BOOST SW V Positive Undervoltage Lockout Measured at V 2.2 2.5 2.8 V UVLO CC Measured at V 2.2 2.5 2.8 V INFF I V Supply Current V = V l 6.5 9 mA VCC CC FB COMP V = 0V, PLLIN Floating l 100 150 m A RUN/SS 3802f 2 SGND TG1 FCB BOOST1 EXTREF BG1 RUN/SS PV CC PGOOD BG2 V BOOST2 INFF PHASEMD TG2 FB2 SW2 U WWW