描述 Description

UCCx8C4x family are high-performance, current-mode PWM controllers. The UCCx8C4x is an enhanced BiCMOS version with pin-for-pin compatibility to the industry standard UCx84xA family and UCx84x family of PWM controllers. The BiCMOS technology offers lower power consumption to improve efficiency as well as faster current sense and oscillator frequency. In addition, lower startup voltage versions of 7 V are offered as UCCx8C40 and UCCx8C41 for use in battery systems. The UCC28C4x series is specified for operation from –40°C to 105°C, and the UCC38C4x series is specified for operation from 0°C to 70°C. Providing necessary features to control fixed frequency, peak current-mode power supplies, this family offers the following performance advantages. The device offers high-frequency operation up to 1 MHz, suitable for high speed applications. The trimmed discharge current enables more precise programming of the maximum duty cycle and dead-time limit when compared to the UCx84x family. Reduced start-up and operating currents minimizes start-up loss and low operating power consumption for improved efficiency. The device also features a fast current-sense-to-output delay time of 35 ns for superior overload protection at the power switch, and a ±1-A peak output current capability with improved rise and fall times for driving large external MOSFETs directly. The UCC38C4x family is offered in 8-pin VSSOP (DGK), 8-pin SOIC (D), and 8-pin PDIP (P) packages.

特性 Features

? Enhanced Replacement for UCx84x and UCx84xA Family With Pin-to-Pin Compatibility
? 1-MHz Operation
? 50-μA Standby Current, 100-μA Maximum
? Low Operating Current of 2.3 mA at 52 kHz
? Fast 35-ns Cycle-by-Cycle Over-Current Limiting
? ±1-A Peak Output Current
? Rail-to-Rail Output Swings with 25-ns Rise and 20-ns Fall Times
? ±1% Initial Trimmed 2.5-V Error Amplifier Reference
? Trimmed Oscillator Discharge Current
? New Undervoltage Lockout Versions
? VSSOP-8 Package Minimizes Board Space