Hamida Gidden, Xiaozhen Han, Quoc Pho, Joe Smith

1
POWER MANAGEMENT SYSTEM
DC-DC Boost Switch-Mode Power Converter with
Ambient Light Control
Faculty Advisor Dr. Hoi Lee
Hamida Gidden, Xiaozhen Han, Quoc Pho, Joe Smith
hkg031000_at_utdallas.edu, xxh042000_at_utdallas.edu,
qap061000_at_utdallas.edu, jgs051000_at_utdallas.edu
Department of Electrical Engineering Erik Jonsson
School of Engineering Computer
Science University of Texas at Dallas Richardson,
Texas 75083-0688, U.S.A.
Project Overview
Detail

• Phase I - Characterize a DC-DC Boost Switch-
• Mode Power Converter (Texas Instruments
• TPS6100x Evaluation Module)
• Phase II Design, build and test
• Power Management System incorporating a
• DC-DC Boost Switch-Mode Power Converter
• Phase III- (Summer contribution)
• Tailor design to meet specifications
• Power three Red LEDs (7V) with four
• Nickel-metal hydride Batteries (5V)
• Increase battery runtime by adjusting
• output power based on ambient light

Circuit Schematic
Relevance in Industry

• Ambient Light Sensing (ALS) capabilities have
  become a standard in the Portable Display Power
  Management Industry
• Existing Products with ALS
• Apple iPhone
• Apple MacBook Air
• Philips HDTV with Ambivision
• Lexus Headlights

Input and Output Voltage at different VSW Duty
Cycles
Our Results

• Successfully designed and built DC-DC Boost
  Switched Mode Power Converter with Ambient Light
  Control prototype.
• Input Voltage 4.8V
• Output Voltage 7.1V
• Output Current
• Dark Level 10mA
• Light Level 30mA
• In dark conditions, power savings of up to 66

System Stability
MAGNITUDE 16.7 dB FREQUENCY 1.62 kHz
Possible Future Enhancements

• Charge pump start-up circuit
• Low Battery Indication
• Implementation into Integrated Circuit
• Add current sensing capability to boost
  converter
• Increase Frequency by ensuring oscillator low
  value equals Vref

PHASE MARGIN 30.5? FREQUENCY 2.94 kHz