UCC38C45DR

IC REG CTRLR MULT TOPOLOGY 8SOIC

1 Features

• Enhanced replacement for UCx84x and UCx84xA family with pin-to-pin compatibility

• Operating frequency: 1MHz Maximum

• 50μA Startup Current, 100μA Maximum

• Low operating current: 2.3mA (at fOSC = 52kHz)

• Fast, cycle-by-cycle overcurrent limiting: 35ns

• Peak driving current: ±1A. Rail-to-rail output:

– 25ns rise time

– 20ns fall time

• ±1% accurate 2.5V error amplifier reference

• Trimmed oscillator discharge current

• Undervoltage lockout protections

• VSSOP-8 package minimizes board space

2 Applications

• Switch-mode power supplies

• General purpose single-ended DC-DC or off-line isolated power converters

• Board mount power modules

3 Description

The 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 7V are offered as UCCx8C40 and UCCx8C41 for use in battery systems. The UCC28C4x series is specified for operation from –40°C to 125°C, and the UCC38C4x series is specified for operation from 0°C to 85°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 1MHz, 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 UCCx8C4x 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 35ns for superior overload protection at the power switch, and a ±1A peak output current capability with improved rise and fall times for driving large external MOSFETs directly.

The UCCx8C4x family is offered in 8-pin VSSOP (DGK) and 8-pin SOIC (D) packages.