Datasheet LT1374 (Analog Devices)
| Manufacturer | Analog Devices |
| Description | 4.5A, 500kHz Step-Down Switching Regulator |
| Pages / Page | 32 / 1 — FEATURES. DESCRIPTIO. Constant 500kHz Switching Frequency. High Power … |
| File Format / Size | PDF / 720 Kb |
| Document Language | English |
FEATURES. DESCRIPTIO. Constant 500kHz Switching Frequency. High Power 16-Pin TSSOP Package Available
Model Line for this Datasheet
- LT1374CFE#PBF LT1374CFE#TRPBF LT1374CR#PBF LT1374CR#TRPBF LT1374CR-5#PBF LT1374CR-5#TRPBF LT1374CR-5SYNC#PBF LT1374CR-5Sync#TRPBF LT1374CR-SYNC#PBF LT1374CR-Sync#TRPBF LT1374CS8#PBF LT1374CS8#TRPBF LT1374CS8-5#PBF LT1374CS8-5#TRPBF LT1374CS8-5SYNC#PBF LT1374CS8-5Sync#TRPBF LT1374CS8-SYNC#PBF LT1374CS8-Sync#TRPBF LT1374CT7#PBF LT1374CT7-5#PBF LT1374HVCFE#PBF LT1374HVCFE#TRPBF LT1374HVCR#PBF LT1374HVCR#TRPBF LT1374HVCS8#PBF LT1374HVCS8#TRPBF LT1374HVIFE#PBF LT1374HVIFE#TRPBF LT1374HVIR#PBF LT1374HVIR#TRPBF LT1374HVIS8#PBF LT1374HVIS8#TRPBF LT1374IFE#PBF LT1374IFE#TRPBF LT1374IR#PBF LT1374IR#TRPBF LT1374IR-5#PBF LT1374IR-5#TRPBF LT1374IR-5SYNC#PBF LT1374IR-SYNC#PBF LT1374IS8#PBF LT1374IS8#TRPBF LT1374IS8-5#PBF LT1374IS8-5#TRPBF LT1374IS8-5SYNC#PBF LT1374IS8-SYNC#PBF LT1374IT7#PBF LT1374IT7-5#PBF
Text Version of Document
LT1374 4.5A, 500kHz Step-Down Switching Regulator
U FEATURES DESCRIPTIO
■
Constant 500kHz Switching Frequency
The LT®1374 is a 500kHz monolithic buck mode switching ■
High Power 16-Pin TSSOP Package Available
regulator. A 4.5A switch is included on the die along with ■
Uses All Surface Mount Components
all the necessary oscillator, control and logic circuitry. High ■
Inductor Size Reduced to 1.8
µ
H
switching frequency allows a considerable reduction in the ■ Saturating Switch Design: 0.07Ω size of external components. The topology is current mode ■ Effective Supply Current: 2.5mA for fast transient response and good loop stability. Both ■ Shutdown Current: 20µA fixed output voltage and adjustable parts are available. ■ Cycle-by-Cycle Current Limiting A special high speed bipolar process and new design tech- ■ Easily Synchronizable niques achieve high efficiency at high switching frequency. Efficiency is maintained over a wide output current range
U
by using the output to bias the circuitry and by utilizing a
APPLICATIO S
supply boost capacitor to saturate the power switch. ■ Portable Computers The LT1374 is available in standard 7-pin DD, TO-220, fused ■ Battery-Powered Systems lead SO-8 and 16-pin exposed pad TSSOP packages. Full ■ Battery Chargers cycle-by-cycle short-circuit protection and thermal shut- ■ Distributed Power down are provided. Standard surface mount external parts may be used, including the inductor and capacitors. There is the optional function of shutdown or synchronization. A shutdown signal reduces supply current to 20µA. Synchro- nization allows an external logic level signal to increase the internal oscillator from 580kHz to 1MHz. , LTC and LT are registered trademarks of Linear Technology Corporation. Protected by U.S. Patents, Including 6111439, 5668493, 5656965
U TYPICAL APPLICATIO 5V Buck Converter Efficiency vs Load Current
D2 100 CMDSH3 OR FMMD914 VOUT = 5V VIN = 10V 95 C2 L = 10µH 0.27µF L1** 90 5 BOOST µH INPUT OUTPUT** VIN V 6V TO 25V SW 5V, 4.25A C3* + 85 LT1374-5 BIAS 10µF TO 50µF DEFAULT SHDN SENSE EFFICIENCY (%) = ON 80 GND VC C1 + D1 C 100µF, 10V C MBRS330T3 75 1.5nF SOLID TANTALUM 70 * RIPPLE CURRENT RATING ≥ IOUT/2 1374 TA01 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 ** INCREASE L1 TO 10µH FOR LOAD CURRENTS ABOVE 3.5A AND TO 20µH ABOVE 4A SEE APPLICATIONS INFORMATION LOAD CURRENT (A) 1374 TA02 1374fd 1
U FEATURES DESCRIPTIO
■
Constant 500kHz Switching Frequency
The LT®1374 is a 500kHz monolithic buck mode switching ■
High Power 16-Pin TSSOP Package Available
regulator. A 4.5A switch is included on the die along with ■
Uses All Surface Mount Components
all the necessary oscillator, control and logic circuitry. High ■
Inductor Size Reduced to 1.8
µ
H
switching frequency allows a considerable reduction in the ■ Saturating Switch Design: 0.07Ω size of external components. The topology is current mode ■ Effective Supply Current: 2.5mA for fast transient response and good loop stability. Both ■ Shutdown Current: 20µA fixed output voltage and adjustable parts are available. ■ Cycle-by-Cycle Current Limiting A special high speed bipolar process and new design tech- ■ Easily Synchronizable niques achieve high efficiency at high switching frequency. Efficiency is maintained over a wide output current range
U
by using the output to bias the circuitry and by utilizing a
APPLICATIO S
supply boost capacitor to saturate the power switch. ■ Portable Computers The LT1374 is available in standard 7-pin DD, TO-220, fused ■ Battery-Powered Systems lead SO-8 and 16-pin exposed pad TSSOP packages. Full ■ Battery Chargers cycle-by-cycle short-circuit protection and thermal shut- ■ Distributed Power down are provided. Standard surface mount external parts may be used, including the inductor and capacitors. There is the optional function of shutdown or synchronization. A shutdown signal reduces supply current to 20µA. Synchro- nization allows an external logic level signal to increase the internal oscillator from 580kHz to 1MHz. , LTC and LT are registered trademarks of Linear Technology Corporation. Protected by U.S. Patents, Including 6111439, 5668493, 5656965
U TYPICAL APPLICATIO 5V Buck Converter Efficiency vs Load Current
D2 100 CMDSH3 OR FMMD914 VOUT = 5V VIN = 10V 95 C2 L = 10µH 0.27µF L1** 90 5 BOOST µH INPUT OUTPUT** VIN V 6V TO 25V SW 5V, 4.25A C3* + 85 LT1374-5 BIAS 10µF TO 50µF DEFAULT SHDN SENSE EFFICIENCY (%) = ON 80 GND VC C1 + D1 C 100µF, 10V C MBRS330T3 75 1.5nF SOLID TANTALUM 70 * RIPPLE CURRENT RATING ≥ IOUT/2 1374 TA01 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 ** INCREASE L1 TO 10µH FOR LOAD CURRENTS ABOVE 3.5A AND TO 20µH ABOVE 4A SEE APPLICATIONS INFORMATION LOAD CURRENT (A) 1374 TA02 1374fd 1
