RT9173D應用電路及參數(shù)資料

Cost-Effective, Peak 3A Sink/Source Bus Termination Regulator

The RT9173D 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 JEDEC SSTL_2 and SSTL_18 or other specific interfaces such as HSTL, SCSI-2 and SCSI-3 etc. devices requirements. The regulator is capable of actively sinking or sourcing continuous 2A or up to 3A transient peak current while regulating an output voltage to within 40mV. The output termination voltage cab 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 RT9173D 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 RT9173D are available in the SOP-8 (Exposed Pad) surface mount packages.

Features

? Ideal for DDR-I, DDR-II and DDR-III VTT Applications
? Sink and Source Current
? 2A Continuous Current
? Peak 3A for DDRI and DDRII
? Peak 2.5A for DDRIII
? Integrated Power MOSFETs
? Generates Termination Voltage for SSTL_2, SSTL _18, HSTL, SCSI-2 and SCSI-3 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
? Available in SOP-8 (Exposed Pad) Packages
? VIN and VCNTL No Power Sequence Issue

? RoHS Compliant and 100% Lead (Pb)-Free
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Application

? Desktop PCs, Notebooks, and Workstations
? Graphics Card Memory Termination
? Set Top Boxes, Digital TVs, Printers
? Embedded Systems
? Active Termination Buses
? DDR-I, DDR-II and DDR-III Memory Systems

Typical Applications Circuit

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

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

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

?RT9173D pdf datasheet