LT1117/LT1117-2.85

The LT1117 is a positive low dropout regulator designed to provide up to 800mA of output current. The device is available in an adjustable version and fixed output voltages of 2.85V, 3.3V and 5V. The 2.85V version is designed specifically to be used in Active Terminators for the SCSI bus. All internal circuitry is designed to operate down to 1V input to output differential. Dropout voltage is guaranteed at a maximum of 1.2V at 800mA, decreasing at lower load currents. On chip trimming adjusts the reference/output voltage to within ± 1%. Current limit is also trimmed in order to minimize the stress on both the regulator and the power source circuitry under overload conditions.

The low profile surface mount SOT-223 package allows the device to be used in applications where space is limited. The LT1117 requires a minimum of 10mF of output capacitance for stability. Output capacitors of this size or larger are normally included in most regulator designs.

Unlike PNP type regulators where up to 10% of the output current is wasted as quiescent current, the quiescent current of the LT1117 flows into the load, increasing efficiency.