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FEATURES

APPLICATIONS

DESCRIPTION

UCD8220

SLUS652D – MARCH 2005 – REVISED OCTOBER 2006

www.ti.com

DIGITALLY MANAGED PUSH-PULL ANALOG PWM CONTROLLERS

• Digitally Managed Switch Mode Power

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• For Digitally Managed Power Supplies Using

Supplies

µCs or the TMS320 ™ DSP Family

• Push-Pull, Half-Bridge, or Full-Bridge

• Voltage or Peak Current Mode Control with

Converters

Cycle-by-Cycle Current Limiting

• Battery Chargers

• Clock input from Digital Controller to set

Operating Frequency and Max Duty Cycle

• Analog PWM Comparator

The UCD8220 analog pulse-width modulator device

• 2-MHz Switching Frequency

is used in digitally managed power supplies using a

• 110-V Input Startup Circuit and Thermal

microcontroller or the TMS320™ DSP family.

Shutdown (UCD8620)

UCD8220

ia

a

double-ended

PWM

controller

• Internal Programmable Slope Compensation

configured with push-pull drive logic.

• 3.3-V, 10-mA Linear Regulator

Systems using the UCD8220 device close the PWM

• DSP/µC Compatible Inputs

feedback loop with traditional analog methods, but

• Dual 4-A TrueDrive™ High Current Drivers

the UCD8220 controller includes circuitry to interpret

a time-domain digital pulse train. The pulse train

• 10-ns Typical Rise and Fall Times with 2.2-nF

contains the operating frequency and maximum duty

• 25-ns Input-to-Output Propagation Delay

cycle limit which are used to control the power supply

• 25-ns Current Sense-to-Output Propagation

operation. This eases implementation of a converter

Delay

with high level control features without the added

complexity or possible PWM resolution limitations of

• Programmable Current Limit Threshold

closing the control loop in the discrete time domain.

• Digital Output Current Limit Flag

• 4.5-V to 15.5-V Supply Voltage Range

• Rated from -40C to 105C

Figure 1. UCD8220 Typical Simplified Push-Pull Converter Application Schematic

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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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TMS320, TrueDrive, PowerPAD are trademarks of Texas Instruments.

3

is a registered trademark of ~ Texas Instruments.

UNLESS

OTHERWISE

NOTED

this

document

contains

Copyright © 2005–2006, Texas Instruments Incorporated

PRODUCTION DATA information 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.