LX8117B-05

The LX8117/8117A/8117B series are positive Low Dropout (LDO) regulators. At the designed maximum load current, the LX8117 series dropout voltage is guaranteed to be 1.2V or lower at 0.8A (LX8117A 1.3V @ 1A). The dropout voltage decreases with load current.

An adjustable output voltage version of the LX8117/17A/17B is available, as well as versions with fixed outputs of 2.5V, 2.85V, 3.3V and 5V. The 2.85V version is specifically designed for use as a component of active termination networks for the SCSI bus. On-chip trimming of the internal voltage reference allows specification of the initial output voltage to within ±1% of its nominal value. The output current-limit point is also trimmed, which helps to minimize stress on both the regulator and the system power source when they are operated under short-circuit conditions. The regulator's internal circuitry will operate at input-to-output differential voltages down to 1V.

Most regulator circuit designs include output capacitors with values in the range of tens to hundreds of microfarads or more. The LX8117/17A/17B typically requires at least 10µF of output capacitance for stable operation.

PNP-type regulators can waste current equal to as much as 10 percent of their output as a quiescent current which flows directly to ground, bypassing the load. Quiescent current from the LX8117/17A/ 17B flows through the load, increasing power-use efficiency and allowing cooler ,operation.

The LX8117 is available in low-profile plastic SOT-223 and D-Pak packages for applications where space is at a premium. The LX8117 is also available in a plastic TO-263 package for instances when the thermal resistance from the circuit die to the environment must be minimized.