UCC2882/-1 UCC3882/-1
Average Current Mode Synchronous Controller With 5-Bit DAC
FEATURES • Combined DAC/Voltage Monit...
UCC2882/-1 UCC3882/-1
Average Current Mode Synchronous Controller With 5-Bit DAC
FEATURES Combined DAC/
Voltage Monitor and PWM
with Synchronous Rectification Functions
5-Bit Digital-to-Analog (DAC) Converter 1% DAC/Reference Combined Accuracy Compatible with 5V and 12V Systems and
12V-only Systems
Low Offset Current Sense Amplifier Programmable Oscillator Frequency Practical
to 700kHz
Foldback Current Limiting Over
voltage and Under
voltage Fault Windows 2Ω Totem Pole Outputs with Programmable
Dead Times to Eliminate Cross-Conduction
Chip Disable Function
BLOCK DIAGRAM
DESCRIPTION
The UCC3882 combines high precision reference and
voltage monitoring circuitry with average current mode PWM synchronous rectification controller circuitry to power high-end microprocessors with a minimum of external components. The UCC3882 converts 5V or 12V to an adjustable output ranging from 1.8VDC to 2.05VDC in 50mV steps and 2.1VDC to 3.5VDC in 100mV steps with 1% DC system accuracy.
The DAC output
voltage is directly compatible with Intel’s 5-bit VID code (Table 1) which covers 1.3V to 2.05V in 50mV steps and 2.1V to 3.5V in 100mV steps. The accuracy of the DAC/reference combination is better than 1%. Under
voltage lockout circuitry assures the correct logic states at the outputs during power up and power down. The over
voltage and under
voltage comparators monitor the system output
voltage and indicate when it rises above or falls below its designed value by more than 9%. A...