Datasheet LT3958 (Analog Devices)
| Hersteller | Analog Devices |
| Beschreibung | High Input Voltage, Boost, Flyback, SEPIC and Inverting Converter |
| Seiten / Seite | 30 / 1 — FeaTures. DescripTion. Wide Input Voltage Range: 5V to 80V. Single … |
| Dateiformat / Größe | PDF / 783 Kb |
| Dokumentensprache | Englisch |
FeaTures. DescripTion. Wide Input Voltage Range: 5V to 80V. Single Feedback Pin for Positive or Negative. Output Voltage
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LT3958 High Input Voltage, Boost, Flyback, SEPIC and Inverting Converter
FeaTures DescripTion
n
Wide Input Voltage Range: 5V to 80V
The LT®3958 is a wide input range, current mode, DC/DC n
Single Feedback Pin for Positive or Negative
converter which is capable of generating either positive
Output Voltage
or negative output voltages. It can be configured as either n
Internal 3.3A/84V Power Switch
a boost, flyback, SEPIC or inverting converter. It features n Current Mode Control Provides Excellent Transient an internal low side N-channel power MOSFET rated for Response 84V at 3.3A and driven from an internal regulated 7.2V n Programmable Operating Frequency (100kHz to supply. The fixed frequency, current-mode architecture 1MHz) with One External Resistor results in stable operation over a wide range of supply n Synchronizeable to an External Clock and output voltages. n Low Shutdown Current < 1µA The operating frequency of LT3958 can be set with an n Internal 7.2V Low Dropout Voltage Regulator external resistor over a 100kHz to 1MHz range, and can n Programmable Input Undervoltage Lockout with be synchronized to an external clock using the SYNC pin. Hysteresis A minimum operating supply voltage of 5V, and a low n Programmable Soft-Start shutdown quiescent current of less than 1µA, make the n Thermally Enhanced QFN (5mm × 6mm) Package LT3958 ideally suited for battery-powered systems. The LT3958 features soft-start and frequency foldback
applicaTions
functions to limit inductor current during start-up. n Automotive L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and No R n SENSE and ThinSOT are trademarks of Analog Devices, Inc. All other trademarks are the Telecom property of their respective owners. Patents pending. n Industrial
Typical applicaTion High Efficiency Boost Converter Efficiency vs Output Current
33µH VOUT V 100 IN 48V V 12V TO 40V IN = 24V 0.5A 4.7µF 4.7µF 95 392k VIN SW ×2 EN/UVLO GND 90 53.6k LT3958 85 SGND SENSE1 SYNC SENSE2 464k EFFICIENCY (%) 80 FBX RT SS VC INTVCC 15.8k 75 41.2k 300kHz 0.33µF 10k 4.7µF 70 0 100 200 300 400 500 10nF OUTPUT CURRENT (mA) 3958 TA01b 3958 TA01a 3958fa For more information www.linear.com/LT3958 1 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Applications Information Typical Applications Package Description Revision History Typical Applications Related Parts
FeaTures DescripTion
n
Wide Input Voltage Range: 5V to 80V
The LT®3958 is a wide input range, current mode, DC/DC n
Single Feedback Pin for Positive or Negative
converter which is capable of generating either positive
Output Voltage
or negative output voltages. It can be configured as either n
Internal 3.3A/84V Power Switch
a boost, flyback, SEPIC or inverting converter. It features n Current Mode Control Provides Excellent Transient an internal low side N-channel power MOSFET rated for Response 84V at 3.3A and driven from an internal regulated 7.2V n Programmable Operating Frequency (100kHz to supply. The fixed frequency, current-mode architecture 1MHz) with One External Resistor results in stable operation over a wide range of supply n Synchronizeable to an External Clock and output voltages. n Low Shutdown Current < 1µA The operating frequency of LT3958 can be set with an n Internal 7.2V Low Dropout Voltage Regulator external resistor over a 100kHz to 1MHz range, and can n Programmable Input Undervoltage Lockout with be synchronized to an external clock using the SYNC pin. Hysteresis A minimum operating supply voltage of 5V, and a low n Programmable Soft-Start shutdown quiescent current of less than 1µA, make the n Thermally Enhanced QFN (5mm × 6mm) Package LT3958 ideally suited for battery-powered systems. The LT3958 features soft-start and frequency foldback
applicaTions
functions to limit inductor current during start-up. n Automotive L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and No R n SENSE and ThinSOT are trademarks of Analog Devices, Inc. All other trademarks are the Telecom property of their respective owners. Patents pending. n Industrial
Typical applicaTion High Efficiency Boost Converter Efficiency vs Output Current
33µH VOUT V 100 IN 48V V 12V TO 40V IN = 24V 0.5A 4.7µF 4.7µF 95 392k VIN SW ×2 EN/UVLO GND 90 53.6k LT3958 85 SGND SENSE1 SYNC SENSE2 464k EFFICIENCY (%) 80 FBX RT SS VC INTVCC 15.8k 75 41.2k 300kHz 0.33µF 10k 4.7µF 70 0 100 200 300 400 500 10nF OUTPUT CURRENT (mA) 3958 TA01b 3958 TA01a 3958fa For more information www.linear.com/LT3958 1 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Applications Information Typical Applications Package Description Revision History Typical Applications Related Parts