Datasheet LT3431 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | High Voltage, 3A, 500kHz Step-Down Switching Regulator |
| Pages / Page | 28 / 1 — FEATURES. DESCRIPTIO. Wide Input Range: 5.5V to 60V. 3A Peak Switch … |
| File Format / Size | PDF / 263 Kb |
| Document Language | English |
FEATURES. DESCRIPTIO. Wide Input Range: 5.5V to 60V. 3A Peak Switch Current. Small Thermally Enhanced 16-Pin TSSOP Package
Model Line for this Datasheet
Text Version of Document
LT3431 High Voltage, 3A, 500kHz Step-Down Switching Regulator
U FEATURES DESCRIPTIO
■
Wide Input Range: 5.5V to 60V
The LT®3431 is a 500kHz monolithic buck switching regu- ■
3A Peak Switch Current
lator that accepts input voltages up to 60V. A high efficiency ■
Small Thermally Enhanced 16-Pin TSSOP Package
3A, 0.1Ω switch is included on the die along with all the nec- ■
Constant 500kHz Switching Frequency
essary oscillator, control and logic circuitry. A current mode ■
Saturating Switch Design: 0.1
Ω architecture provides fast transient response and good loop ■
Peak Switch Current Maintained Over
stability.
Full Duty Cycle Range
Special design techniques and a new high voltage process ■ Effective Supply Current: 2.5mA achieve high efficiency over a wide input range. Efficiency ■ Shutdown Current: 30µA is maintained over a wide output current range by using the ■ 1.2V Feedback Reference Voltage output to bias the circuitry and by utilizing a supply boost ■ Easily Synchronizable capacitor to saturate the power switch. Patented circuitry ■ Cycle-by-Cycle Current Limiting maintains peak switch current over the full duty cycle range.
U
A shutdown pin reduces supply current to 30µA and the de-
APPLICATIO S
vice can be externally synchronized from 580kHz to 700kHz with logic level inputs. ■ Industrial and Automotive Power Supplies ■ Portable Computers The LT3431 is available in a thermally enhanced 16-pin ■ Battery Chargers TSSOP package. ■ Distributed Power Systems , LTC and LT are registered trademarks of Linear Technology Corporation.
U TYPICAL APPLICATIO 5V, 2A Buck Converter
MMSD914TI 6 0.22µF
Efficiency vs Load Current
BOOST 10 V µH** IN 3, 4 2, 5 VOUT 12V VIN SW 5V 100 (TRANSIENTS 2A 2.2µF† VIN = 12V TO 60V) LT3431 30BQ060 100V L = 15µH CERAMIC V 47µF OUT = 5V 90 15 10 SHDN BIAS CERAMIC VOUT = 3.3V 14 12 15.4k 80 SYNC FB GND VC 4.99k 1, 8, 9, 16 11 70 EFFICIENCY (%) 220pF 1.5k 60 15nF 50 0 0.5 1.0 1.5 2.0 2.5 LOAD CURRENT (A) ** INCREASE INDUCTOR VALUE FOR LOAD CURRENTS ABOVE 2A 3431 TA02 (SEE APPLICATIONS INFORMATION—MAXIMUM OUTPUT LOAD CURRENT) 3431 TA01 † UNITED CHEMI-CON THCS50EZA225ZT sn3431 3431fs 1
U FEATURES DESCRIPTIO
■
Wide Input Range: 5.5V to 60V
The LT®3431 is a 500kHz monolithic buck switching regu- ■
3A Peak Switch Current
lator that accepts input voltages up to 60V. A high efficiency ■
Small Thermally Enhanced 16-Pin TSSOP Package
3A, 0.1Ω switch is included on the die along with all the nec- ■
Constant 500kHz Switching Frequency
essary oscillator, control and logic circuitry. A current mode ■
Saturating Switch Design: 0.1
Ω architecture provides fast transient response and good loop ■
Peak Switch Current Maintained Over
stability.
Full Duty Cycle Range
Special design techniques and a new high voltage process ■ Effective Supply Current: 2.5mA achieve high efficiency over a wide input range. Efficiency ■ Shutdown Current: 30µA is maintained over a wide output current range by using the ■ 1.2V Feedback Reference Voltage output to bias the circuitry and by utilizing a supply boost ■ Easily Synchronizable capacitor to saturate the power switch. Patented circuitry ■ Cycle-by-Cycle Current Limiting maintains peak switch current over the full duty cycle range.
U
A shutdown pin reduces supply current to 30µA and the de-
APPLICATIO S
vice can be externally synchronized from 580kHz to 700kHz with logic level inputs. ■ Industrial and Automotive Power Supplies ■ Portable Computers The LT3431 is available in a thermally enhanced 16-pin ■ Battery Chargers TSSOP package. ■ Distributed Power Systems , LTC and LT are registered trademarks of Linear Technology Corporation.
U TYPICAL APPLICATIO 5V, 2A Buck Converter
MMSD914TI 6 0.22µF
Efficiency vs Load Current
BOOST 10 V µH** IN 3, 4 2, 5 VOUT 12V VIN SW 5V 100 (TRANSIENTS 2A 2.2µF† VIN = 12V TO 60V) LT3431 30BQ060 100V L = 15µH CERAMIC V 47µF OUT = 5V 90 15 10 SHDN BIAS CERAMIC VOUT = 3.3V 14 12 15.4k 80 SYNC FB GND VC 4.99k 1, 8, 9, 16 11 70 EFFICIENCY (%) 220pF 1.5k 60 15nF 50 0 0.5 1.0 1.5 2.0 2.5 LOAD CURRENT (A) ** INCREASE INDUCTOR VALUE FOR LOAD CURRENTS ABOVE 2A 3431 TA02 (SEE APPLICATIONS INFORMATION—MAXIMUM OUTPUT LOAD CURRENT) 3431 TA01 † UNITED CHEMI-CON THCS50EZA225ZT sn3431 3431fs 1
