LT1375 - 1.5A, 500kHz Step-Down Switching Regulators

A special high speed bipolar process and new design techniques achieve high efficiency at high switching frequency. Efficiency is maintained over a wide output current range by using the output to bias the circuitry and by utilizing a supply boost capacitor to saturate the power switch. A shutdown signal will reduce supply current to 20µA on both parts. The LT1375 can be externally synchronized from 580kHz to 900kHz with logic level inputs.

The LT1375/LT1376 fit into standard 8-pin PDIP and SO packages, as well as a fused lead 16-pin SO with much lower thermal resistance. Full cycle-by-cycle short-circuit protection and thermal shutdown are provided. Standard surface mount external parts are used, including the inductor and capacitors.

For low input voltage applications with 3.3V output, see LT1507. This is a functionally identical part that can operate with input voltages between 4.5V and 12V.

Features
  • Constant 500kHz Switching Frequency
  • Easily Synchronizable
  • Uses All Surface Mount Components
  • Inductor Size Reduced to 5µH
  • Saturating Switch Design: 0.4 ohms
  • Effective Supply Current: 2.5mA
  • Shutdown Current: 20µA
  • Cycle-by-Cycle Current Limiting
Typical Application

Applications
  • Portable Computers
  • Battery-Powered Systems
  • Battery Charger
  • Distributed Power
Packaging


Order Information
Part NumberPackageTempPrice(1-99)Price (1k)*
LT1375CN8-5#PBFN-8C$4.33$3.50
LT1375CN8#PBFN-8C$4.33$3.50
LT1375CS8-5#PBFSO-8C$4.50$3.65
LT1375CS8-5#TRPBFSO-8C$3.71
LT1375CS8#PBFSO-8C$3.80$3.20
LT1375CS8#TRPBFSO-8C$3.26
LT1375HVCS8#PBFSO-8C$4.20$3.50
LT1375HVCS8#TRPBFSO-8C$3.56
LT1375HVIS8#PBFSO-8I$5.05$4.24
LT1375HVIS8#TRPBFSO-8I$4.31
LT1375IN8-5#PBFN-8I$5.25$4.20
LT1375IN8#PBFN-8I$5.25$4.20
LT1375IS8-5#PBFSO-8I$5.40$4.35
LT1375IS8-5#TRPBFSO-8I$4.41
LT1375IS8#PBFSO-8I$4.55$3.85
LT1375IS8#TRPBFSO-8I$3.91
Demo Boards
Part NumberDescriptionPrice
DC084B-ALT1375CS8 | ADJUSTABLE 5V BUCK CONVERTERContact Factory
DC084B-BLT1375CS8-5 | FIXED 5V BUCK CONVERTERContact Factory
Datasheet
Application Note
Reliability Data
LTspice
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LT1375 Demo Circuit - 1.5A, 500kHz Step-Down Switching Regulators (6V-25V to 5V @ 1A)