LT1074 - Step-Down Switching Regulator
The LT1074 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.
Features
Typical Application  | Applications
Packaging     |
Order Information
| Part Number | Package | Temp | Price(1-99) | Price (1k)* |
|---|---|---|---|---|
| LT1074CT#06PBF | TO-220 | C | $6.17 | $5.05 |
| LT1074CT#30PBF | TO-220 | C | $6.62 | $5.50 |
| LT1074CT#PBF | TO-220 | C | $6.17 | $5.05 |
| LT1074CT7#06PBF | TO-220 | C | $7.17 | $5.90 |
| LT1074CT7#PBF | TO-220 | C | $7.17 | $5.90 |
| LT1074HVCT#06PBF | TO-220 | C | $9.25 | $7.60 |
| LT1074HVCT#PBF | TO-220 | C | $9.25 | $7.60 |
| LT1074HVCT7#06PBF | TO-220 | C | $10.25 | $8.40 |
| LT1074HVCT7#PBF | TO-220 | C | $10.25 | $8.40 |
| LT1074HVIT#06PBF | TO-220 | I | $12.50 | $10.25 |
| LT1074HVIT#30PBF | TO-220 | I | $12.95 | $10.70 |
| LT1074HVIT#PBF | TO-220 | I | $12.50 | $10.25 |
| LT1074HVIT7#06PBF | TO-220 | I | $13.50 | $10.80 |
| LT1074HVIT7#35PBF | TO-220 | I | $13.95 | $11.25 |
| LT1074HVIT7#PBF | TO-220 | I | $13.50 | $10.80 |
| LT1074IT#06PBF | TO-220 | I | $8.33 | $6.85 |
| LT1074IT#PBF | TO-220 | I | $8.33 | $6.85 |
| LT1074IT7#PBF | TO-220 | I | $9.15 | $7.35 |
- LT1074 Package Drawing LT1074
- LT1074 Package Drawing LT1074
- LT1074 Package Drawing LT1074
- LT1074 Package Drawing LT1074
- AN35 - Step Down Switching Regulators
- AN44 - LT1074/LT1076 Design Manual
- AN46 - Efficiency and Power Characteristics of Switching Regulator Circuits
- AN98 - Signal Sources, Conditioners and Power Circuitry Circuits of the Fall, 2004
- DN48 - No Design Switching Regulator 5V, 5A Buck (Step Down) Regulator
- DN49 - No Design Switiching Regulator 5V Buck-Boost (Positive to Negative) Regulator
- R117 Reliability Data
- LT1074 Footprints and Symbols
- LT1074 Demo Circuit - Step-Down Switching Regulator (10V-40V to 5V @ 5A)
