UCC2808A1EP, UCC2808A2EP

LOW POWER CURRENT MODE PUSHPULL PWM

SGLS187A − SEPTEMBER 2003 − REVISED SEPTEMBER 2003

1

POST OFFICE BOX 655303

− One Assembly/Test Site, One Fabrication

Site

−40

°C to 125°C

Sources (DMS) Support

Configuration

Improve Dynamic Response

† Component qualification in accordance with JEDEC and industry

standards to ensure reliable operation over an extended

temperature range. This includes, but is not limited to, Highly

Accelerated Stress Test (HAST) or biased 85/85, temperature

cycle, autoclave or unbiased HAST, electromigration, bond

intermetallic life, and mold compound life. Such qualification

testing should not be viewed as justifying use of this component

beyond specified performance and environmental limits.

Bandwidth Product

Peak-Source Current, 1-A Peak-Sink

Current

description/ordering information

The UCC2808A is a family of BiCMOS push-pull, high-speed, low-power, pulse-width modulators. The

UCC2808A contains all of the control and drive circuitry required for off-line or dc-to-dc fixed frequency

current-mode switching power supplies with minimal external parts count.

The UCC2808A dual output drive stages are arranged in a push-pull configuration. Both outputs switch at half

the oscillator frequency using a toggle flip-flop. The dead time between the two outputs is typically 60 ns to

200 ns depending on the values of the timing capacitor and resistors, thus limiting each output stage duty cycle

to less than 50%.

The UCC2808A family offers a variety of package options and choice of undervoltage lockout levels. The family

has UVLO thresholds and hysteresis options for off-line and battery powered systems. Thresholds are shown

in the ordering information table.

The UCC2808A is an enhanced version of the UCC2808 family. The significant difference is that the A versions

feature an internal discharge transistor from the CS pin to ground, which is activated each clock cycle during

the oscillator dead time. The feature discharges any filter capacitance on the CS pin during each cycle and helps

minimize filter capacitor values and current sense delay.

Copyright

 2003, Texas Instruments Incorporated

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily include

testing of all parameters.

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

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COMP

FB

CS

RC

VDD

OUTA

OUTB

GND

D PACKAGE

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