Datasheet LT8711 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | Micropower Synchronous Multitopology Controller with 42V Input Capability |
| Pages / Page | 38 / 1 — FEATURES. DESCRIPTION. Easily Configurable as a Synchronous Buck, Boost,. … |
| Revision | A |
| File Format / Size | PDF / 1.1 Mb |
| Document Language | English |
FEATURES. DESCRIPTION. Easily Configurable as a Synchronous Buck, Boost,. SEPIC, ZETA or Nonsynchronous Buck-Boost Converter
Model Line for this Datasheet
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LT8711 Micropower Synchronous Multitopology Controller with 42V Input Capability
FEATURES DESCRIPTION
n
Easily Configurable as a Synchronous Buck, Boost,
The LT®8711 is a multitopology current mode PWM control-
SEPIC, ZETA or Nonsynchronous Buck-Boost Converter
ler that can easily be configured as a synchronous buck, n
Wide Input Range: 4.5V to 42V (VIN Can Operate
boost, SEPIC, ZETA or as a nonsynchronous buck-boost
to 0V, when EXTVCC > 4.5V)
converter. Its dual gate drive voltage inputs optimize gate n
Automatic Low Noise Burst Mode
®
Operation
driver efficiency. n
Low IQ in Burst Mode Operation (15μA Operating)
The 15µA no-load quiescent current with the output voltage n Input Voltage Regulation for High Impedance Source in regulation extends operating run time in battery powered n 100% Duty Cycle in Dropout (Buck Mode) systems. Low ripple Burst Mode operation enables high n 2A Gate Drivers (BG and TG) efficiency at very light loads while maintaining low output n Adjustable Soft-Start with One Capacitor voltage ripple. The LT8711's fixed switching frequency can n Frequency Programmable from 100kHz to 750kHz be set from 100kHz to 750kHz or can be synchronized to n Can Be Synchronized to External Clock an external clock. n Available in 20-Lead TSSOP and 20-Lead 3mm×4mm QFN Packages The additional features include 100% duty cycle capability when in buck mode, a topology selection pin and adjustable soft-start. LT8711 is available in the 20-lead TSSOP and
APPLICATIONS
20-lead 3mm × 4mm QFN packages. All registered trademarks and trademarks are the property of their respective owners. n General Purpose DC/DC Conversion n Automotive Systems n Industrial Supplies n Solar Panel Power Converter
TYPICAL APPLICATION 400kHz 5V to 40V Input/12V Output Nonsynchronous Buck Boost
VIN
Efficiency vs Load Current
5V TO 40V 10µF ×6 V 100 IN BIAS 50V, X7R 2.2µF EN/FBIN 90 VOUT EXTVCC INTVEE 100pF 80 LT8711 TG OPMODE M1 70 2.2µF L1 VOUT D1 4.7µH D2 12V, 60 INTVCC ISN 3.5A (VIN >16V) 50 60.4k 2.5A (9V < VIN < 16V) RT 4mΩ 1M 1.5A (VIN < 9V) 40 EFFICIENCY (%) SYNC ISP 100µF ×2 30 330nF 16V, X7R V GND M2 IN = 5V 69.8k 20 V SS IN = 12V V 100pF BG 10 IN = 24V VIN = 36V CSP 4mΩ 0 2.2nF CSN 0.001 0.01 0.1 1 4 110k V LOAD CURRENT (A) C FB 8711 TA01b 8711 TA01a Rev A Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Start-Up and Fault Sequence Operation Applications Information Appendix Typical Applications Package Description Typical Application Related Parts
FEATURES DESCRIPTION
n
Easily Configurable as a Synchronous Buck, Boost,
The LT®8711 is a multitopology current mode PWM control-
SEPIC, ZETA or Nonsynchronous Buck-Boost Converter
ler that can easily be configured as a synchronous buck, n
Wide Input Range: 4.5V to 42V (VIN Can Operate
boost, SEPIC, ZETA or as a nonsynchronous buck-boost
to 0V, when EXTVCC > 4.5V)
converter. Its dual gate drive voltage inputs optimize gate n
Automatic Low Noise Burst Mode
®
Operation
driver efficiency. n
Low IQ in Burst Mode Operation (15μA Operating)
The 15µA no-load quiescent current with the output voltage n Input Voltage Regulation for High Impedance Source in regulation extends operating run time in battery powered n 100% Duty Cycle in Dropout (Buck Mode) systems. Low ripple Burst Mode operation enables high n 2A Gate Drivers (BG and TG) efficiency at very light loads while maintaining low output n Adjustable Soft-Start with One Capacitor voltage ripple. The LT8711's fixed switching frequency can n Frequency Programmable from 100kHz to 750kHz be set from 100kHz to 750kHz or can be synchronized to n Can Be Synchronized to External Clock an external clock. n Available in 20-Lead TSSOP and 20-Lead 3mm×4mm QFN Packages The additional features include 100% duty cycle capability when in buck mode, a topology selection pin and adjustable soft-start. LT8711 is available in the 20-lead TSSOP and
APPLICATIONS
20-lead 3mm × 4mm QFN packages. All registered trademarks and trademarks are the property of their respective owners. n General Purpose DC/DC Conversion n Automotive Systems n Industrial Supplies n Solar Panel Power Converter
TYPICAL APPLICATION 400kHz 5V to 40V Input/12V Output Nonsynchronous Buck Boost
VIN
Efficiency vs Load Current
5V TO 40V 10µF ×6 V 100 IN BIAS 50V, X7R 2.2µF EN/FBIN 90 VOUT EXTVCC INTVEE 100pF 80 LT8711 TG OPMODE M1 70 2.2µF L1 VOUT D1 4.7µH D2 12V, 60 INTVCC ISN 3.5A (VIN >16V) 50 60.4k 2.5A (9V < VIN < 16V) RT 4mΩ 1M 1.5A (VIN < 9V) 40 EFFICIENCY (%) SYNC ISP 100µF ×2 30 330nF 16V, X7R V GND M2 IN = 5V 69.8k 20 V SS IN = 12V V 100pF BG 10 IN = 24V VIN = 36V CSP 4mΩ 0 2.2nF CSN 0.001 0.01 0.1 1 4 110k V LOAD CURRENT (A) C FB 8711 TA01b 8711 TA01a Rev A Document Feedback For more information www.analog.com 1 Document Outline Features Applications Typical Application Description Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Start-Up and Fault Sequence Operation Applications Information Appendix Typical Applications Package Description Typical Application Related Parts
