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


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The RT9045 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 RT9045 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
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 Enable Input;OCP;Stable with Ceramic Capacitor
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 Regulator2009/06/05
Technical Documents
TitleLast UpdateShareDownload
Richtek Selection Guide (Oct., 2021)2021/11/23
Part NumberPackage TypePackage Qty.Free SampleBuy From Authorized Distributor
RT9045GSPPSOP-82500 Request Not available
RT9045GSPPSOP-82500 Request Buy from Distributor
RT9045ZSPPSOP-82500 Not available Not available