Description
   This evaluation board is based on the PM6670S and represents a complete DDR2/3 power supply regulator for portable applications designed to meet JEDEC specifications. It integrates a constant on-time (COT) buck controller, a 2 Apk sink/source low drop-out regulator and a 15 mA low noise buffered reference. The COT architecture assures fast transient response supporting both polymeric and ceramic output capacitors. An embedded integrator control loop compensates the DC voltage error due to the output ripple. The 2 Apk sink/source linear regulator provides the memory termination voltage with fast load transient response.

FEATUREs
◾ 4.5 V to 28 V input voltage range
◾ 0.9 V, ±1% voltage reference
◾ 1.8 V (DDR2) or 1.5 V (DDR3) fixed output
   voltages
◾ 0.9 V to 2.6 V adjustable output voltage
◾ 1.237 V ±1% reference voltage available
◾ Very fast load transient response
◾ Constant on-time loop control
◾ No RSENSE current sensing using the RDS(on)
   of the low-side MOSFETs
◾ Negative current limit
◾ Latched OVP, UVP and thermal shutdown
◾ Fixed 3 ms soft-start
◾ Selectable pulse-skipping at light load
◾ Selectable no-audible (33 kHz) pulse-skip
   mode
◾ All ceramic output capacitors application
   supported
◾ Output voltage ripple compensation