Datasheet LTC7801 (Analog Devices)

ManufacturerAnalog Devices
Description150V Low IQ, Synchronous Step-Down DC/DC Controller
Pages / Page38 / 1 — FeaTures. DescripTion. Wide VIN Range: 4V to 140V (150V Abs Max). Wide …
File Format / SizePDF / 2.4 Mb
Document LanguageEnglish

FeaTures. DescripTion. Wide VIN Range: 4V to 140V (150V Abs Max). Wide Output Voltage Range: 0.8V to 60V

Datasheet LTC7801 Analog Devices

Text Version of Document

LTC7801 150V Low IQ, Synchronous Step-Down DC/DC Controller
FeaTures DescripTion
n
Wide VIN Range: 4V to 140V (150V Abs Max)
The LTC®7801 is a high performance step-down switching n
Wide Output Voltage Range: 0.8V to 60V
regulator DC/DC controller that drives an all N-channel n
Adjustable Gate Drive Level: 5V to 10V (OPTI-DRIVE)
synchronous power MOSFET stage that can operate from n
Low Operating IQ: 40μA (Shutdown = 10μA)
input voltages up to 140V. A constant frequency current n
100% Duty Cycle Operation
mode architecture allows a phase-lockable frequency of n
No External Bootstrap Diode Required
up to 850kHz. n Selectable Gate Drive UVLO Thresholds The gate drive voltage can be programmed from 5V to 10V n Onboard LDO or External NMOS LDO for DRVCC to allow the use of logic or standard-level FETs to maxi- n EXTVCC LDO Powers Drivers from VOUT mize efficiency. An integrated switch in the top gate driver n Phase-Lockable Frequency (75kHz to 850kHz) eliminates the need for an external bootstrap diode. An n Programmable Fixed Frequency (50kHz to 900kHz) internal charge pump allows for 100% duty cycle operation. n Selectable Continuous, Pulse-Skipping or Low Ripple Burst Mode® Operation at Light Loads The low 40μA no-load quiescent current extends operating n Adjustable Burst Clamp run time in battery-powered systems. OPTI-LOOP® com- n Power Good Output Voltage Monitor pensation allows the transient response to be optimized n Programmable Input Overvoltage Lockout over a wide range of output capacitance and ESR values. n Small 24-Lead 4mm × 5mm QFN or TSSOP Packages The LTC7801 features a precision 0.8V reference and power good output indicator. The output voltage can be
applicaTions
programmed between 0.8V to 60V using external resistors. L, LT, LTC, LTM, Burst Mode, OPTI-LOOP, PolyPhase, Linear Technology and the Linear logo n Automotive and Industrial Power Systems are registered trademarks of Analog Devices, Inc. All other trademarks are the property of their respective owners. Protected by U.S. Patents including 5481178, 5705919, 5929620, 6144194, n High Voltage Battery Operated Systems 6177787, 6580258. n Telecommunications Power Systems
Typical applicaTion High Efficiency High Voltage 12V Output Step-Down Regulator Efficiency and Power Loss vs Load Current
VIN 7V to 140V 100µF 100 10k VIN RUN NDRV TG 90 0.1µF *V EFFICIENCY OUT FOLLOWS VIN WHEN VIN < 12V DRV 80 CC BOOST 1k 4.7µF 33µH 6mΩ POWER LOSS (mW) VOUT 70 LTC7801 12V* SW 5A 60 INTVCC BG 150µF 50 V 100 0.1µF CPUMP_EN IN = 24V x3 POWER LOSS 40 VIN = 48V SENSE+ EFFICIENCY (%) ITH 30 1nF 10 SENSE– 10k SS 20 0.1µF EXTVCC 10 100pF FREQ 511k VFB 0 1 4.7nF 30.1k 0.0001 0.001 0.01 0.1 1 10 36.5k GND LOAD CURRENT (A) 7801 TA01b 7801 TA01a 7801f For more information www.linear.com/LTC7801 1 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Typical Applications Package Description Typical Application Related Parts