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.ApplicationsBuck Converter with Output Voltage Range of 2.5V to 50VTapped-Inductor Buck Converter with 10A Output at 5VPositive-to-Negative ConverterNegative Boost ConverterMultiple Output Buck Converter