مدار مجتمع (آی سی) آی سی‌کاربرد ویژه

Product Attributes

Introduction

The UC3838 and the UC3838A family of magnetic amplifier controllers contains the circuitry to generate and amplify a low-level analog error signal along with a high voltage-compliant current source. This source provides the reset current necessary to enable a magnetic amplifier to regulate and control a power supply output in the range of 2 A to 20 A. The UC3838A originally was a parametric improvement version of the UC3838 which since has been used for both versions. There is no difference between the UC3838A and UC3838 version. By controlling the reset current to a magnetic amplifier, this device defines the amount of volt-seconds the magnetic amplifier blocks before switching to the conducting state. Magnetic amplifiers are ideal for post-regulators for multiple-output power supplies where each output can be independently controlled with efficiencies up to 99%. With a square or pulse-width modulated input voltage, a magnetic amplifier blocks a portion of this input waveform, allowing just enough to pass to provide a regulated output. With the UC3838/A, only the magnetic amplifier coil, three diodes, and an output L-C filter are necessary to implement a complete closed-loop regulator. The UC3838/A contains a precision 2.5-V reference, two uncommitted high-gain operational amplifier and a high-gain PNP-equivalent current source which can deliver up to 100 mA of magnetic amplifier reset current and with -120-V capability. These devices are available in a plastic batwing DIP (N), wide body SOIC (DW), and PLCC (Q) package for operation over a -20°C to 85°C temperature range.

Features

• Independent 1% Reference
• Two Uncommitted, Identical Operational Amplifiers
• 100-mA Reset Current Source With -120-V Capability
• 5-V to 40-V Analog Operation 5-W DIP Package