LT1176 Datasheet | Linear Technology

LT1176/LT1176-5 Step-Down Switching Regulator Features s s s s s s s s 1.2A On-Board Switch 100k Hz Switching Frequency Excellent Dynamic Behavior DIP and Surface Mount Packages Only 8m A Quiescent Current Preset 5V Output Available Operates Up to 35V Input Micropower Shutdown Mode tion. The power switch, all oscillator and control circuitry, and all current limit ponents are included on the chip. The topology is a classic positive “buck” configuration but several design innovations allows 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 below ground. The LT1176 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 LT1176 nearly bust-proof for output overloads or shorts. The input voltage range as a buck converter is 8V to 35V, but a selfboot feature allows input voltages as low as 5V in the inverting and boost configurations. The LT1176 is available in a low cost 8-lead DIP package with frequency preset at 100k Hz and current limit at 1.7A An adjustable output is offered as well as a preset 5V version. For further design details and application help, see the LT1074/LT1076 data sheet and Application Note 44. APPLICATI s s s s Buck Converter with Output Voltage Range of 2.5V to 30V Positive-to-Negative Converter Negative Boost Converter Mulitple Output Buck Converter DESCRIPTIO The LT1176 is a 1A monolithic bipolar switching regulator which requires only a few external parts for normal opera- TYPICAL APPLICATI Basic 5V Positive Buck Converter L1- 100µH 10V T0 35V VIN LT1176-5 SENSE VC R3 2.7k C3 100µF C2 0.01µF VSW 1N5819 EFFICIENCY (%) 5V, 0.8A + - COILTRONICS #100-1-52...