UCC3830- Datasheet, PDF (1/10 Pages) Texas Instruments – 5-Bit Microprocessor Power Supply Controller

UCC3830-4/-5/-6
5-Bit Microprocessor Power Supply Controller
FEATURES
• 5-Bit Digital-to-Analog Converter
(DAC)
• Supports 4-Bit and 5-Bit
Microprocessor VID Codes
• Combined DAC/Voltage Monitor
and PWM Functions
• 1% DAC/Reference
• Current Sharing
• 100kHz, 200kHz, 400kHz
Oscillator Frequency Options
• Foldback Current Limiting
• Overvoltage and Undervoltage
Fault Windows
• Undervoltage Lockout
• 4Ω Totem Pole Output
• Chip Disable Function
DESCRIPTION
The UCC3830-4/-5/-6 is a fully integrated single chip solution ideal for power-
ing high performance microprocessors. The chip includes an average current
mode PWM controller, has a fully integrated 5-Bit DAC, and includes an
on-board precision reference and voltage monitor circuitry. The UCC3830-x
converts 5VDC to an adjustable output, ranging from 3.5VDC down to 1.8VDC
with 1% DC system accuracy (see Table 1). The UCC3830-x fully supports
Intel’s 4-bit Pentium® Pro and 5-bit Pentium® II VID codes.
The accuracy of the DAC/reference combination is 1%. The overvoltage and
undervoltage comparators monitor the system output voltage and indicate
when it rises above or falls below its programmed value by more than 8.5%. A
second overvoltage protection comparator pulls the current amplifier output
voltage low to force zero duty cycle when the system output voltage exceeds
its designed value by more than 17.5%. This comparator also terminates the
cycle. Undervoltage lockout circuitry assures the correct logic states at the
outputs during powerup and powerdown. The gate output can be disabled by
bringing the CAO/ENBL pin to below 0.8V.
(continued)
BLOCK DIAGRAM
02/99
UDG-96188-2