Datasheet LT3480 (Analog Devices)
| Hersteller | Analog Devices |
| Beschreibung | 36V, 2A, 2.4MHz Step-Down Switching Regulator with 70µA Quiescent Current |
| Seiten / Seite | 24 / 1 — FEATURES. DESCRIPTION. Wide Input Range:. Operation from 3.6V to 36V. … |
| Dateiformat / Größe | PDF / 388 Kb |
| Dokumentensprache | Englisch |
FEATURES. DESCRIPTION. Wide Input Range:. Operation from 3.6V to 36V. Over-Voltage Lockout Protects Circuits
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LT3480 36V, 2A, 2.4MHz Step-Down Switching Regulator with 70µA Quiescent Current
FEATURES DESCRIPTION
n
Wide Input Range:
The LT®3480 is an adjustable frequency (200kHz to
Operation from 3.6V to 36V
2.4MHz) monolithic buck switching regulator that ac-
Over-Voltage Lockout Protects Circuits
cepts input voltages up to 36V (60V maximum). A high
through 60V Transients
efficiency 0.25 switch is included on the die along with n
2A Maximum Output Current
a boost Schottky diode and the necessary oscillator, con- n
Low Ripple Burst Mode® Operation
trol, and logic circuitry. Current mode topology is used
70µA IQ at 12VIN to 3.3VOUT
for fast transient response and good loop stability. Low
Output Ripple < 15mV
ripple Burst Mode operation maintains high efficiency at n
Adjustable Switching Frequency: 200kHz to 2.4MHz
low output currents while keeping output ripple below n
Low Shutdown Current: IQ < 1µA
15mV in a typical application. In addition, the LT3480 can n
Integrated Boost Diode
further enhance low output current efficiency by draw- n
Synchronizable Between 250kHz to 2MHz
ing bias current from the output when VOUT is above 3V. n Power Good Flag Shutdown reduces input supply current to less than 1µA n Saturating Switch Design: 0.25 On-Resistance while a resistor and capacitor on the RUN/SS pin provide a n 0.790V Feedback Reference Voltage controlled output voltage ramp (soft-start). A power good n Output Voltage: 0.79V to 20V flag signals when VOUT reaches 86% of the programmed n Soft-Start Capability output voltage. The LT3480 is available in 10-lead MSOP n Small 10-Lead Thermally Enhanced MSOP and and 3mm × 3mm DFN packages with exposed pads for (3mm × 3mm) DFN Packages low thermal resistance.
APPLICATIONS
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Burst Mode is a registered trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. n Automotive Battery Regulation n Power for Portable Products n Distributed Supply Regulation n Industrial Supplies
TYPICAL APPLICATION 3.3V Step-Down Converter Efficiency
VIN VOUT 100 4.5V TO 36V 3.3V TRANSIENT V 2A IN BD V TO 60V OUT = 5V 90 OFF ON RUN/SS BOOST V 0.47µF OUT = 3.3V 80 14k 4.7µH VC LT3480 SW 4.7µF RT 70 470pF EFFICIENCY (%) PG 316k 60 40.2k SYNC FB V GND IN = 12V L = 5.6µH 100k 22µF 50 F = 800 kHz 0 0.5 1.0 1.5 2 LOAD CURRENT (A) 3480 TA01 3480 TA01b 3480fe For more information www.linear.com/LT3480 1 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts
FEATURES DESCRIPTION
n
Wide Input Range:
The LT®3480 is an adjustable frequency (200kHz to
Operation from 3.6V to 36V
2.4MHz) monolithic buck switching regulator that ac-
Over-Voltage Lockout Protects Circuits
cepts input voltages up to 36V (60V maximum). A high
through 60V Transients
efficiency 0.25 switch is included on the die along with n
2A Maximum Output Current
a boost Schottky diode and the necessary oscillator, con- n
Low Ripple Burst Mode® Operation
trol, and logic circuitry. Current mode topology is used
70µA IQ at 12VIN to 3.3VOUT
for fast transient response and good loop stability. Low
Output Ripple < 15mV
ripple Burst Mode operation maintains high efficiency at n
Adjustable Switching Frequency: 200kHz to 2.4MHz
low output currents while keeping output ripple below n
Low Shutdown Current: IQ < 1µA
15mV in a typical application. In addition, the LT3480 can n
Integrated Boost Diode
further enhance low output current efficiency by draw- n
Synchronizable Between 250kHz to 2MHz
ing bias current from the output when VOUT is above 3V. n Power Good Flag Shutdown reduces input supply current to less than 1µA n Saturating Switch Design: 0.25 On-Resistance while a resistor and capacitor on the RUN/SS pin provide a n 0.790V Feedback Reference Voltage controlled output voltage ramp (soft-start). A power good n Output Voltage: 0.79V to 20V flag signals when VOUT reaches 86% of the programmed n Soft-Start Capability output voltage. The LT3480 is available in 10-lead MSOP n Small 10-Lead Thermally Enhanced MSOP and and 3mm × 3mm DFN packages with exposed pads for (3mm × 3mm) DFN Packages low thermal resistance.
APPLICATIONS
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Burst Mode is a registered trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. n Automotive Battery Regulation n Power for Portable Products n Distributed Supply Regulation n Industrial Supplies
TYPICAL APPLICATION 3.3V Step-Down Converter Efficiency
VIN VOUT 100 4.5V TO 36V 3.3V TRANSIENT V 2A IN BD V TO 60V OUT = 5V 90 OFF ON RUN/SS BOOST V 0.47µF OUT = 3.3V 80 14k 4.7µH VC LT3480 SW 4.7µF RT 70 470pF EFFICIENCY (%) PG 316k 60 40.2k SYNC FB V GND IN = 12V L = 5.6µH 100k 22µF 50 F = 800 kHz 0 0.5 1.0 1.5 2 LOAD CURRENT (A) 3480 TA01 3480 TA01b 3480fe For more information www.linear.com/LT3480 1 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Electrical Characteristics Typical Performance Characteristics Pin Functions Block Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts