D0 7805 VOLTAGE REGULATOR

The LM1085 is a regulator with a maximum dropout of 1.5 V at 3 A of load current. It has the same pin-out as TI?s industry standard LM317. Two resistors are required to set the output voltage of the adjustable output voltage version of the LM1085. Fixed output voltage versions integrate the adjust resistors. The LM1085 circuit includes a zener trimmed bandgap reference, current limiting and thermal shutdown.

The LM3940 is a 1-A low-dropout regulator designed to provide 3.3 V from a 5-V supply. The LM3940 is ideally suited for systems which contain both 5-V and 3.3-V logic, with prime power provided from a 5-V bus. Because the LM3940 is a true low dropout regulator, it can hold its 3.3-V output in regulation with input voltages as low as 4.5 V. The TO-220 package of the LM3940 means that in most applications the full 1 A of load current can be delivered without using an additional heat sink.

The MIC4576 is a series of easy-to-use fixed and adjustable BiCMOS step-down (buck) switch-mode voltage regulators. The 200 kHz MIC4576 duplicates the pinout and function of the 52 kHz LM2576. The higher switching frequency may allow up to a 2:1 reduction in output filter inductor size. The MIC4576 is available in 3.3V, and 5V fixed output versions or a 1.23V to 33V adjustable output version. Both versions are capable of driving a 3A load with excellent line and load regulation. The feedback voltage is guaranteed to ?2% tolerance for adjustable versions, and the output voltage is guaranteed to ?3% for fixed versions, within specified voltages and load conditions. The oscillator frequency is guaranteed to ?10%. In Shutdown mode, the regulator draws less than 200 ?A shutdown current. The regulator performs cycle-by-cycle current limiting and thermal shutdown for protection under fault conditions. This series of simple switch-mode regulators requires a minimum number of external components and can operate using a standard series of inductors. Frequency compensation is provided internally. The MIC4576 is available in TO-220 (T) and TO-263 (U) packages for the industrial temperature range.

TL431 is three-terminal adjustable regulator series with a guaranteed thermal stability over applicable temperature ranges. The output voltage may be set to any value between VREF (approximately 2.5 volts) and 36 volts with two external resistors. These devices have a typical dynamic output impedance of 0.2?. Active output circuitry provides a very sharp turn-on characteristic, making these devices excel lent replacement for zener diodes in many applications.