Datasheet LT3682 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | 1A Micropower Step-Down Switching Regulator |
| Pages / Page | 24 / 1 — FEATURES. DESCRIPTION. Wide Input Range:. Operation from 3.6V to 36V. … |
| File Format / Size | PDF / 265 Kb |
| Document Language | English |
FEATURES. DESCRIPTION. Wide Input Range:. Operation from 3.6V to 36V. Overvoltage Lockout Protects Circuits through. 60V
Model Line for this Datasheet
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LT3682 1A Micropower Step-Down Switching Regulator
FEATURES DESCRIPTION
n
Wide Input Range:
The LT®3682 is an adjustable frequency (250kHz to
Operation from 3.6V to 36V
2.2MHz) monolithic buck switching regulator that accepts
Overvoltage Lockout Protects Circuits through
input voltages up to 36V. A high effi ciency 0.5Ω switch is
60V Transients
included on the device along with a boost diode and the n
1A Output Current
necessary oscillator, control, and logic circuitry. Current n
Low Ripple Burst Mode
®
Operation
mode topology is used for fast transient response and good
IQ = 75μA at 12VIN to 3.3VOUT
loop stability. A SYNC pin allows the user to synchronize the
Output Ripple < 15mVP-P
part to an external clock, and to choose between Low Ripple n
Adjustable Switching Frequency: 250kHz to 2.2MHz
Burst Mode operation and standard PWM operation. n
Short-Circuit Protected
The Low Ripple Burst Mode maintains high effi ciency at n
Synchronizable Between 300kHz and 2.2MHz
low output currents while keeping output ripple below n 0.8V Feedback Reference Voltage 15mV in typical applications. Shutdown reduces input n Output Voltage 0.8V to 20V supply current to less than 1μA while a resistor and n Soft-Start Capability capacitor on the RUN/SS pin provide a controlled output n Power Good Flag voltage ramp (soft-start). A power good fl ag signals when n Small 12-Pin Thermally Enhanced 3mm × 3mm VOUT reaches 90% of the programmed output voltage. DFN Package Protection circuitry senses the current in the power switch and external Schottky catch diode to protect the LT3682 against short-circuit conditions. Frequency foldback and
APPLICATIONS
thermal shutdown provide additional protection. n Automotive Battery Regulation The LT3682 is available in a 12-Pin 3mm × 3mm DFN with n Automotive Entertainment Systems exposed pad for low thermal resistance. n Industrial Supplies L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Burst Mode n Power for Portable Products is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. n Distributed Supply Regulation
TYPICAL APPLICATION 5V Step-Down Converter Effi ciency
V V OUT 100 IN 5V 6.9V TO 36V 0.9A, V TRANSIENT TO 60V IN r 6.9V V 1A, V OUT = 5V IN r 12V 90 VIN BD ON OFF RUN/SS BOOST VOUT = 3.3V 0.22μF 80 2.2μF VC 10μH LT3682 R SW T 70 16.2k EFFICIENCY (%) PG DA 40.2k 536k 60 VIN = 12V SYNC FB L = 10µH 470pF GND PGND f = 800 kHz 102k 10μF 50 0 0.2 0.4 0.6 0.8 1 3682 TA01 LOAD CURRENT (A) f = 800kHz 3682 TA01b 3682f 1
FEATURES DESCRIPTION
n
Wide Input Range:
The LT®3682 is an adjustable frequency (250kHz to
Operation from 3.6V to 36V
2.2MHz) monolithic buck switching regulator that accepts
Overvoltage Lockout Protects Circuits through
input voltages up to 36V. A high effi ciency 0.5Ω switch is
60V Transients
included on the device along with a boost diode and the n
1A Output Current
necessary oscillator, control, and logic circuitry. Current n
Low Ripple Burst Mode
®
Operation
mode topology is used for fast transient response and good
IQ = 75μA at 12VIN to 3.3VOUT
loop stability. A SYNC pin allows the user to synchronize the
Output Ripple < 15mVP-P
part to an external clock, and to choose between Low Ripple n
Adjustable Switching Frequency: 250kHz to 2.2MHz
Burst Mode operation and standard PWM operation. n
Short-Circuit Protected
The Low Ripple Burst Mode maintains high effi ciency at n
Synchronizable Between 300kHz and 2.2MHz
low output currents while keeping output ripple below n 0.8V Feedback Reference Voltage 15mV in typical applications. Shutdown reduces input n Output Voltage 0.8V to 20V supply current to less than 1μA while a resistor and n Soft-Start Capability capacitor on the RUN/SS pin provide a controlled output n Power Good Flag voltage ramp (soft-start). A power good fl ag signals when n Small 12-Pin Thermally Enhanced 3mm × 3mm VOUT reaches 90% of the programmed output voltage. DFN Package Protection circuitry senses the current in the power switch and external Schottky catch diode to protect the LT3682 against short-circuit conditions. Frequency foldback and
APPLICATIONS
thermal shutdown provide additional protection. n Automotive Battery Regulation The LT3682 is available in a 12-Pin 3mm × 3mm DFN with n Automotive Entertainment Systems exposed pad for low thermal resistance. n Industrial Supplies L, LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Burst Mode n Power for Portable Products is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. n Distributed Supply Regulation
TYPICAL APPLICATION 5V Step-Down Converter Effi ciency
V V OUT 100 IN 5V 6.9V TO 36V 0.9A, V TRANSIENT TO 60V IN r 6.9V V 1A, V OUT = 5V IN r 12V 90 VIN BD ON OFF RUN/SS BOOST VOUT = 3.3V 0.22μF 80 2.2μF VC 10μH LT3682 R SW T 70 16.2k EFFICIENCY (%) PG DA 40.2k 536k 60 VIN = 12V SYNC FB L = 10µH 470pF GND PGND f = 800 kHz 102k 10μF 50 0 0.2 0.4 0.6 0.8 1 3682 TA01 LOAD CURRENT (A) f = 800kHz 3682 TA01b 3682f 1
