Datasheet LT7101 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | 105V, 1A Low EMI Synchronous Step-Down Regulator with Fast Current Programming |
| Pages / Page | 38 / 1 — FEATURES. DESCRIPTION. Wide VIN Range: 4.4V to 105V (110V Abs Max). … |
| File Format / Size | PDF / 3.2 Mb |
| Document Language | English |
FEATURES. DESCRIPTION. Wide VIN Range: 4.4V to 105V (110V Abs Max). Ultralow EMI/EMC Emissions: CISPR 25 Compliant
Model Line for this Datasheet
Text Version of Document
LT7101 105V, 1A Low EMI Synchronous Step-Down Regulator with Fast Current Programming
FEATURES DESCRIPTION
n
Wide VIN Range: 4.4V to 105V (110V Abs Max)
The LT®7101 is a high efficiency, monolithic synchro- n
Ultralow EMI/EMC Emissions: CISPR 25 Compliant
nous step-down DC/DC converter utilizing a constant n
2µA IQ When Regulating 48VIN to 3.3VOUT
frequency, average current mode control architecture. It n
Fast and Accurate Output Current Programming and
operates from an input voltage range of 4.4V to 105V and
Monitoring with No External RSENSE
provides an adjustable regulated output voltage from 1V n
Brick Wall Current Limit
to VIN while delivering up to 1A of output current. n
Low Minimum On-Time: 35ns
The LT7101 features high frequency operation and a low n
Wide VOUT Range: 1V to VIN
minimum on-time that reduce inductor size and enable n
100% Maximum Duty Cycle Operation
constant-frequency operation even at very high step- n Programmable Fixed Frequency: 200kHz to 2MHz down ratios. In addition, the LT7101 achieves the lowest n Eight, Pin-Selectable Fixed (1.2V to 15V) or possible dropout voltage with 100% maximum duty cycle Adjustable Output Voltages operation. During light load operation, converter efficiency n Selectable Continuous, Pulse-Skipping, or Low and output ripple can be optimized by selecting Burst Ripple Burst Mode® Operation at Light Loads Mode, pulse-skipping or forced continuous operation. n PLL Synchronization to External Clock n EXTV The LT7101 includes accurate, high speed average cur- CC LDO Powers Chip from VOUT = 3.3V to 40V n OPTI-LOOP® or Fixed Internal Compensation rent programming and monitoring without the need for n Input and Output Overvoltage Protection an external sense resistor. Additional features include a n Thermally Enhanced (5mm × 6mm) QFN Package bypass LDO to maximize efficiency, fixed or adjustable output voltage and loop compensation, and a wide array of protection features to enhance reliability.
APPLICATIONS
All registered trademarks and trademarks are the property of their respective owners. n Battery Chargers and CC/CV Supplies n Automotive and Military Systems n Industrial, Avionics and Heavy Equipment n Medical Instruments and Telecommunication Systems
TYPICAL APPLICATION Efficiency vs Load Current 5V to 105V Input to 5V/1A Output Step-Down Regulator
100 fSW = 300kHz 95 FIGURE 14 CIRCUIT VIN VIN BOOST 90 5V TO 105V 4.7µF 0.1µF LT7101 47µH V 85 OUT RUN SW 5V 80 I 1A CTRL VFB 75 OVLO EXTVCC 47µF 70 V CURRENT PRG2 IMON EFFICIENCY (%) MONITOR 65 PLLIN/MODE ITH V 60 IN = 12V FREQ INTV VIN = 24V CC 55 VIN = 48V SGND PGND 1µF VIN = 72V 500.1 1 10 100 1000 7101 TA01a LOAD CURRENT (mA) 7101 TA01b Rev. 0 Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Typical Applications Package Description Typical Application Related Parts
FEATURES DESCRIPTION
n
Wide VIN Range: 4.4V to 105V (110V Abs Max)
The LT®7101 is a high efficiency, monolithic synchro- n
Ultralow EMI/EMC Emissions: CISPR 25 Compliant
nous step-down DC/DC converter utilizing a constant n
2µA IQ When Regulating 48VIN to 3.3VOUT
frequency, average current mode control architecture. It n
Fast and Accurate Output Current Programming and
operates from an input voltage range of 4.4V to 105V and
Monitoring with No External RSENSE
provides an adjustable regulated output voltage from 1V n
Brick Wall Current Limit
to VIN while delivering up to 1A of output current. n
Low Minimum On-Time: 35ns
The LT7101 features high frequency operation and a low n
Wide VOUT Range: 1V to VIN
minimum on-time that reduce inductor size and enable n
100% Maximum Duty Cycle Operation
constant-frequency operation even at very high step- n Programmable Fixed Frequency: 200kHz to 2MHz down ratios. In addition, the LT7101 achieves the lowest n Eight, Pin-Selectable Fixed (1.2V to 15V) or possible dropout voltage with 100% maximum duty cycle Adjustable Output Voltages operation. During light load operation, converter efficiency n Selectable Continuous, Pulse-Skipping, or Low and output ripple can be optimized by selecting Burst Ripple Burst Mode® Operation at Light Loads Mode, pulse-skipping or forced continuous operation. n PLL Synchronization to External Clock n EXTV The LT7101 includes accurate, high speed average cur- CC LDO Powers Chip from VOUT = 3.3V to 40V n OPTI-LOOP® or Fixed Internal Compensation rent programming and monitoring without the need for n Input and Output Overvoltage Protection an external sense resistor. Additional features include a n Thermally Enhanced (5mm × 6mm) QFN Package bypass LDO to maximize efficiency, fixed or adjustable output voltage and loop compensation, and a wide array of protection features to enhance reliability.
APPLICATIONS
All registered trademarks and trademarks are the property of their respective owners. n Battery Chargers and CC/CV Supplies n Automotive and Military Systems n Industrial, Avionics and Heavy Equipment n Medical Instruments and Telecommunication Systems
TYPICAL APPLICATION Efficiency vs Load Current 5V to 105V Input to 5V/1A Output Step-Down Regulator
100 fSW = 300kHz 95 FIGURE 14 CIRCUIT VIN VIN BOOST 90 5V TO 105V 4.7µF 0.1µF LT7101 47µH V 85 OUT RUN SW 5V 80 I 1A CTRL VFB 75 OVLO EXTVCC 47µF 70 V CURRENT PRG2 IMON EFFICIENCY (%) MONITOR 65 PLLIN/MODE ITH V 60 IN = 12V FREQ INTV VIN = 24V CC 55 VIN = 48V SGND PGND 1µF VIN = 72V 500.1 1 10 100 1000 7101 TA01a LOAD CURRENT (mA) 7101 TA01b Rev. 0 Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Order Information Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Typical Applications Package Description Typical Application Related Parts
