Datasheet LTC3777 (Analog Devices)

LTC3777 150V VIN and VOUT Synchronous 4-Switch Buck-Boost Controller + Switching Bias Supply
FEATURES DESCRIPTION
n
4-Switch Current Mode Single Inductor Architecture
The LTC®3777 is a high performance buck-boost switching
Allows VIN Above, Below or Equal to VOUT
regulator controller that operates from input voltages n
Wide VIN Range: 4.5V to 150V
above, below or equal to the output voltage. The constant n
Wide Output Voltage Range: 1.2V ≤ VOUT ≤ 150V
frequency current mode architecture allows a phase-lockable n
Synchronous Rectification: Up to 99% Efficiency
frequency of up to 600kHz, while an input/output constant n
±1% 1.2V Voltage Reference
current loop provides support for battery charging. The n
Input or Output Average Current Limit
150V integrated switching bias supply is a high efficiency n
Integrated 12µA IQ, 150V, 85mA, Switching Bias
step-down regulator that draws only 12µA typical DC supply
for Optimal Thermal Performance
current with a regulated output voltage at no load. n
Programmable 6V to 10V DRVCC Optimizes Efficiency
With a wide 4.5V to 150V input and output range and n No Top FET Refresh Noise in Boost or Buck Mode seamless transfers between operating regions, the n VOUT Disconnected from VIN During Shutdown LTC3777 is ideal for industrial, telecom and battery- n Phase-Lockable Fixed Frequency (50kHz to 600kHz) powered systems. n No Reverse Current During Start-Up n 150V Rated RUN Pin with Accurate Turn-On Threshold The LTC3777 features a power good output indicator n Thermally Enhanced 48-Lead e-LQFP Package and a MODE pin to select between pulse-skipping mode or forced continuous mode of operation. The PLLIN pin
APPLICATIONS
allows the IC to be synchronized to an external clock. The n SS pin ramps the output voltage during start-up. Current Industrial, Transportation, Medical, Military, Avionics foldback limits MOSFET heat dissipation during short- All registered trademarks and trademarks are the property of their respective owners. circuit conditions.
TYPICAL APPLICATION
4mΩ VIN VOUT 16V TO 120V 48V, 10A 30µF 20µF 56µF 1k VINSNS BOOST1 15µH 5Ω 5µF V 0.22µF IN
Efficiency and Power Loss
0.1µF DRV SW1 CC TG1
vs Input Voltage
133k 10µF LTC3777 BG1 100 30 VINOV 100Ω 1.21k SENSEP 98 24 SENSEN EFFICIENCY 4mΩ POWER LOSS (W) BVIN 220pF 100Ω 475k 1µF BOV SGND 96 18 PGND BRUN BVOUT 220µH BG2 94 12 12V BSW BOOST2 EFFICIENCY (%) 85mA BVFB 0.22µF 715k BGND 51.1k SW2 92 6 44µF TG2 VOUT = 48V POWER LOSS EXTV I CC AVGSNSP IOUT = 10A 1µF 4.7µF 100Ω 90 0 0 12 24 36 48 60 72 84 96 108 120 10k IAVGSNSN 1k RUN 100Ω VIN VOLTAGE (V) 3777 TA01b PGOOD VOUTSNS 2.2µF 100k VFB V5 100pF 0.1µF ITH 12.1k SS MODE FREQ PLLIN 56.2k 10k 10nF 3777 TA01a Rev A Document Feedback For more information www.analog.com 1 Document Outline FEATURES DESCRIPTION APPLICATIONS TYPICAL APPLICATION ABSOLUTE MAXIMUM RATINGS PIN CONFIGURATION ORDER INFORMATION ELECTRICAL CHARACTERISTICS TYPICAL PERFORMANCE CHARACTERISTICS TYPICAL PERFORMANCE CHARACTERISTICS – SWITCHING BIAS SUPPLY PIN FUNCTIONS BLOCK DIAGRAM OPERATION APPLICATIONS INFORMATION PACKAGE DESCRIPTION REVISION HISTORY TYPICAL APPLICATION RELATED PARTS