Cost-Effective, 1.8A Sink/Source Bus Termination Regulator


Update Alert Share

The RT9045A is a simple, cost-effective and high-speed linear regulator designed to generate termination voltage in Double Data Rate (DDR) memory system to comply with the devices requirements. The regulator is capable of actively sinking or sourcing up to 1.8A while regulating an output voltage to within 20mV. The output termination voltage can be tightly regulated to track VDDQ / 2 by two external voltage divider resistors or the desired output voltage can be programmed by externally forcing the REFEN pin voltage.

The RT9045A also incorporates a high-speed differential amplifier to provide ultra-fast response in line/load transient. Other features include extremely low initial offset voltage, excellent load regulation, current limiting in bi-directions and on-chip thermal shutdown protection.


  • Desktop PCs, Notebooks, and Workstations
  • Graphics Card Memory Termination
  • Set Top Boxes, Digital TVs, Printers
  • Embedded Systems
  • Active Termination Buses
  • DDR Memory Systems
  • Motherboards
  • LCD TV
  • Notebooks
Key Spec.
Status Active
Vin (min) (V) 1
Vin (max) (V) 5.5
VTT Output Tolerance (max) (+/- mV) 13
Isource/Isink (max) (A) 3.5
Standby Current (typ) (mA) 0.02
Features OCP
Package Type PSOP-8
  • Ideal for DDR VTT Applications
  • Sink and Source Current :
    ► DDRII 1.8A Sink/Source @ VIN = 1.8V
    ► DDRIII 1.5A Sink/Source @ VIN = 1.5V
    ► LPDDRIII 1.2A Sink/Source @ VIN = 1.35V
    ► DDRIV 1.2A Sink/Source @ VIN = 1.2V
  • Integrated Power MOSFETs
  • Generate Termination Voltage for DDR Memory Interfaces
  • Stable with Output Ceramic Capacitor
  • High Accuracy Output Voltage at Full-Load
  • Output Adjustment by Two External Resistors
  • Low External Component Count
  • Shutdown for Suspend to RAM (STR) Functionality with High Impedance Output
  • Current Limiting Protection
  • On-Chip Thermal Protection
  • RoHS Compliant
TitleLast UpdateShareDownload
Cost-Effective, 1.8A Sink/Source Bus Termination Regulator2015/05/07