RT9199应用电路及参数资料

Cost-EffecTIve, 2A Peak Sink/Source Bus TerminaTIon Regulator

The RT9199 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 peak 2A for DDRII or 1.5A for DDRIII while regulating an output voltage to within 20mV. The output termination voltage can be tightly regulated to track 1/2VDDQ by two external voltage divider resistors or the desired output voltage can be pro-grammed by externally forcing the REFEN pin voltage.
The RT9199 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 shut-down protection.
The RT9199 are available in both SOP-8 and SOP-8 (Exposed Pad) surface mount packages.

Features

• Ideal for DDRII / DDRIII VTT Applications
• Sink and Source Current :
ο Peak 2A for DDRII
ο Peak 1.5A for DDRIII
• Integrated Power MOSFETs
l Generate Termination Voltage for DDR Memory Interfaces
• 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 and 100% Lead (Pb)-Free

Application

• Desktop PCs, Notebooks, and Workstations
• Graphics Card Memory Termination
• Set Top Boxes, Digital TVs, Printers
• Embedded Systems
• Active Termination Buses
• DDR/II Memory Systems

Typical Applications Circuit

R1 = R2 = 100kW, RTT = 50W / 33W / 25W

COUT(MIN) = 10mF (Ceramic) + 1000mF under the worst case testing condition

RDUMMY = 1kW as for VOUT discharge when VIN is not presented but VCNTL is presented

CSS = 1mF, CIN = 470mF (Low ESR), CCNTL = 47mF

 RT9199 pdf datasheet