
Semtech Corporation
DESCRIPTION
The SC1182/3 combines a synchronous voltage mode controller with two low-dropout linear regulators providing most of the circuitry necessary to implement three DC/DC converters for powering advanced microprocessors such as Pentium® II (Klamath) or Deschutes.
The SC1182/3 switching section features an integrated 5 bit D/A converter, pulse by pulse current limiting, integrated power good signaling, and logic compatible shutdown. The SC1182/3 switching section operates at a fixed frequency of 200kHz, providing an optimum compromise between size, efficiency and cost in the intended application areas. The integrated D/A converter provides programmability of output voltage from 2.0V to 3.5V in 100mV increments and 1.30V to 2.05V in 50mV increments with no external components.
The SC1182/3 linear sections are low dropout regulators. The SC1182 supplies 1.5V for GTL bus and 2.5V for non-GTL I/O.
FEATURES
• Synchronous design, enables no heatsink solution
• 95% efficiency (switching section)
• 5 bit DAC for output programmability
• On chip power good function
• Designed for Intel Pentium® ll VRM8.1 requirements
• 1.5V, 2.5V or Adj. @ 1% for linear section
APPLICATIONS
• Pentium® ll or Deschutes microprocessor supplies
• Flexible motherboards
• 1.3V to 3.5V microprocessor supplies
• Programmable triple power supplies