UC3833

The UC1832 and UC1833 series of precision linear regulators include all the ontrol functions required in the design of very low dropout linear regulators.Additionally, they feature an innovative duty-ratio current limiting technique hich provides peak load capability while limiting the average power dissipation f the external pass transistor during fault conditions. When the load current eaches an accurately programmed threshold, a gated-astable timer is nabled, which switches the regulator's pass device off and on at an externally rogrammable duty-ratio. During the on-time of the pass element, the output urrent is limited to a value slightly higher than the trip threshold of the duty-ratio imer. The constant-current-limit is programmable on the UCx832 to allow igher peak current during the on-time of the pass device. With duty-ratio control,high initial load demands and short circuit protection may both be accommodated ithout extra heat sinking or foldback current limiting. Additionally, if he timer pin is grounded, the duty-ratio timer is disabled, and the IC operates n constant-voltage/constant-current regulating mode.

These IC's include a 2 Volt (±1%) reference, error amplifier, UVLO, and a high urrent driver that has both source and sink outputs, allowing the use of either PN or PNP external pass transistors. Safe operation is assured by the inclusion f under-voltage lockout (UVLO) and thermal shutdown.

The UC1833 family includes the basic functions of this design in a low-cost, 8-pin mini-dip package, while the UC1832 series provides added versatility with he availability of 14 pins. Packaging options include plastic (N suffix), or ceramic J suffix). Specified operating temperature ranges are: commercial (0°C o 70°C), order UC3832/3 (N or J); industrial (25°C to 85°C), order UC2832/3 N or J); and military (55°C to 125°C), order UC1832/3J. Surface mount ackaging is also available.