LT1074 Step-Down Switching Regulator

The LT®1074 is a 5A (LT1076 is rated at 2A) monolithic bipolar switching regulator which requires only a few external parts for normal operation. The power switch, all oscillator and control circuitry, and all current limit components,are included on the chip. The topology is a classic positive “buck” configuration but several design innovations allow this device to be used as a positive-to-negative converter, a negative boost converter, and as a flyback converter. The switch output is specified to swing 40V below ground, allowing the LT1074 to drive a tapped-inductor in the buck mode with output currents up to 10A.

The LT1074 uses a true analog multiplier in the feedback loop. This makes the device respond nearly instantaneously to input voltage fluctuations and makes loop gain independent of input voltage. As a result, dynamic behavior of the regulator is significantly improved over previous designs.

On-chip pulse by pulse current limiting makes the LT1074 nearly bust-proof for output overloads or shorts. The input voltage range as a buck converter is 8V to 60V, but a self-boot feature allows input voltages as low as 5V in the inverting and boost configurations.

The LT1074 is available in lowcost TO-220 or DD packages with frequency pre-set at 100kHz and current limit at 6.5A (LT1076 =2.6A). A 7-pin TO-220 package is also available which allows current limit to be adjusted down to zero. In addition, full micropower shutdown can be programmed. See Application Note 44 for design details

A fixed 5V output, 2A version is also available. See LT1076-5.

产品特点 Features
  • 5A Onboard Switch (LT1074)
  • Operates Up to 60V Input
  • 100kHz Switching Frequency
  • Greatly Improved Dynamic Behavior
  • Available in Low Cost 5 and 7-Lead Packages
  • Only 8.5mA Quiescent Current
  • Programmable Current Limit
  • Micropower Shutdown Mode
参数
LT1074 参数
应用
  • Buck Converter with Output Voltage Range of 2.5V to 50V
  • Tapped-Inductor Buck Converter with 10A Output at 5V
  • Positive-to-Negative Converter
  • Negative Boost Converter
  • Multiple Output Buck Converter
典型应用图
LT1074 典型应用
LT1074 订购信息和价格参考Package Variations and Pricing
器件型号 封装 引脚 温度 价格 (以 1 ~ 99 片为批量) 价格 (以 1000 片为批量) *
LT1074CT TO-220 5 C $6.17  $5.05 
LT1074CT#06PBF TO-220 5 C $6.17  $5.05 
LT1074CT#30PBF TO-220 5 C $6.62  $5.50 
LT1074CT#PBF TO-220 5 C $6.17  $5.05 
LT1074CT7 TO-220 7 C $7.17  $5.90 
LT1074CT7#06PBF TO-220 7 C $7.17  $5.90 
LT1074CT7#PBF TO-220 7 C $7.17  $5.90 
LT1074HVCT TO-220 5 C $9.25  $7.60 
LT1074HVCT#06PBF TO-220 5 C $9.25  $7.60 
LT1074HVCT#PBF TO-220 5 C $9.25  $7.60 
LT1074HVCT7 TO-220 7 C $10.25  $8.40 
LT1074HVCT7#06PBF TO-220 7 C $10.25  $8.40 
LT1074HVCT7#PBF TO-220 7 C $10.25  $8.40 
LT1074HVIT TO-220 5 I $12.50  $10.25 
LT1074HVIT#06PBF TO-220 5 I $12.50  $10.25 
LT1074HVIT#30PBF TO-220 5 I $12.95  $10.70 
LT1074HVIT#PBF TO-220 5 I $12.50  $10.25 
LT1074HVIT7 TO-220 7 I $13.50  $10.80 
LT1074HVIT7#35PBF TO-220 7 I $13.95  $11.25 
LT1074HVIT7#PBF TO-220 7 I $13.50  $10.80 
LT1074IT TO-220 5 I $8.33  $6.85 
LT1074IT#06PBF TO-220 5 I $8.33  $6.85 
LT1074IT#PBF TO-220 5 I $8.33  $6.85 
LT1074IT7 TO-220 7 I $9.15  $7.35 
LT1074IT7#PBF TO-220 7 I $9.15  $7.35 
LT1074 数据手册及相关资料下载
  1. 数据手册(英文) : LT1074/LT1076- Step-Down Switching Regulator.PDF
  2. 应用指南 (英文) : AN35 - Step Down Switching Regulators.PDF
  3. 应用指南 (英文) : AN44 - LT1074/LT1076 Design Manual.PDF
  4. 应用指南 (英文) : AN46 - Efficiency and Power Characteristics of Switching Regulator Circuits.PDF
  5. 应用指南 (英文) : AN98 - Signal Sources, Conditioners and Power Circuitry Circuits of the Fall, 2004.PDF
  6. 设计要点 (英文) : DN48 - No Design Switching Regulator 5V, 5A Buck (Step Down) Regulator.PDF
  7. 设计要点 (英文) : DN49 - No Design Switiching Regulator 5V Buck-Boost (Positive to Negative) Regulator.PDF
  8. 可靠性数据 : R117 Reliability Data .PDF