UCD8220_16 Datasheet, PDF (1/28 Pages) Texas Instruments – DIGITALLY MANAGED PUSH-PULL ANALOG PWM CONTROLLERS

UCD8220
www.ti.com
SLUS652D – MARCH 2005 – REVISED OCTOBER 2006
DIGITALLY MANAGED PUSH-PULL ANALOG PWM CONTROLLERS
FEATURES
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•23 For Digitally Managed Power Supplies Using
µCs or the TMS320 ™ DSP Family
• Voltage or Peak Current Mode Control with
Cycle-by-Cycle Current Limiting
• Clock input from Digital Controller to set
Operating Frequency and Max Duty Cycle
• Analog PWM Comparator
• 2-MHz Switching Frequency
• 110-V Input Startup Circuit and Thermal
Shutdown (UCD8620)
• Internal Programmable Slope Compensation
• 3.3-V, 10-mA Linear Regulator
• DSP/µC Compatible Inputs
• Dual 4-A TrueDrive™ High Current Drivers
• 10-ns Typical Rise and Fall Times with 2.2-nF
• 25-ns Input-to-Output Propagation Delay
• 25-ns Current Sense-to-Output Propagation
Delay
• Programmable Current Limit Threshold
• Digital Output Current Limit Flag
• 4.5-V to 15.5-V Supply Voltage Range
• Rated from -40C to 105C
APPLICATIONS
• Digitally Managed Switch Mode Power
Supplies
• Push-Pull, Half-Bridge, or Full-Bridge
Converters
• Battery Chargers
DESCRIPTION
The UCD8220 analog pulse-width modulator device
is used in digitally managed power supplies using a
microcontroller or the TMS320™ DSP family.
UCD8220 ia a double-ended PWM controller
configured with push-pull drive logic.
Systems using the UCD8220 device close the PWM
feedback loop with traditional analog methods, but
the UCD8220 controller includes circuitry to interpret
a time-domain digital pulse train. The pulse train
contains the operating frequency and maximum duty
cycle limit which are used to control the power supply
operation. This eases implementation of a converter
with high level control features without the added
complexity or possible PWM resolution limitations of
closing the control loop in the discrete time domain.
Figure 1. UCD8220 Typical Simplified Push-Pull Converter Application Schematic
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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
TMS320, TrueDrive, PowerPAD are trademarks of Texas Instruments.
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is a registered trademark of ~ Texas Instruments.
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UNLESS OTHERWISE NOTED this document contains
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.
Copyright © 2005–2006, Texas Instruments Incorporated