General Description

The CM8500A is a switching regulator designed to provide a desired output voltage or termination voltage for various applications by converting voltage supplies ranging from 2.0V to 5.0V. The CM8500A can be implemented to produce regulated output voltages in two different modes. In the default mode, when the VIN/2 pin is open, the output voltage is 50% of the VCCQ. The CM8500A can also be used to produce various user-defined voltages by forcing a voltage on the VIN/2 pin. In this case, the output voltage follows the VIN/2 pin input voltage. The switching regulator is capable of sourcing or sinking up to 3A of current while regulating an output V TT voltage to within 3% or less.

The CM8500A, used in conjunction with series termination resistors, provides an excellent voltage source for active termination schemes of high speed transmission lines as those seen in high speed memory buses and distributed backplane designs.

The voltage output of the regulator can be used as a termination voltage for other bus interface standards such as SSTL, CMOS, Rambus ,GTL+, VME, LV-CMOS, LV-TTL, and PECL.

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Features

• 16 pin PTSSOP and PSOP package
• Source and sink up to 3A, no heat sink requiredu Integrated Power MOSFETs
• Output voltage can be programmed by external resistors
• Separate voltages for VCCQ and PVDD
• V OUT of ¡Ó3% or less at 3A
• Minimum external components
• Shutdown for standby or suspend mode operation
• Thermal shutdown protection
• 6A Low Noise Current Limit Protection
• External Soft Start
• Rail to Rail output Buck Converter

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Applications

• Mother Board
• PCI/AGP Graphics
• Game/ Play Station
• Set Top Box
• IPC
• SCSI-III Bus terminator
• Buck Converter

• CM8500AIT: 16-PIN PTSSOP (PT16)
• CM8500AIS: 16-PIN PSOP (PS16)
  

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Datasheet PDF file

Demo Board Layout Guide PDF file

Application Note 1 PDF file