AME, Inc.
AT9173
Bus Termination Regulator
n General Description
The AT9173 is a voltage regulator which could
convert the input voltage ranging from 1.8V to 5V to an
output voltage that user settled. The regulator can
provide sourcing or sinking current.The AT9173, used
in conjunction with series termination resistors,
provides an excellent voltage source for active
termination schemes of high speed transmission lines
as those seen in high speed memory buses and
distributed backplane designs.
The voltage output of the regulator can be used as a
termination voltage for DDR SDRAM.
Current limits in both sourcing and sinking mode, plus
on-chip thermal shutdown make the circuit tolerant of
the output fault conditions.
n Features
● Support Both DDR I (1.25VTT) and DDR II
(0.9VTT) Requirements
● Capable of Sourcing and Sinking Current
● Current-limiting Protection
● Thermal Protection
● Integrated Power MOSFETs
● Generates Termination Voltages for SSTL-2
● High Accuracy Output Voltage at Full-Load
● Adjustable VOUT by External Resistors
● Minimum External Components
● Shutdown for Standby or Suspend Mode
Operation with High-impedance Output
n Applications
● DDRI/DDRII Memory Termination Supply
● Active Termination Buses
● Desktop PC,NoTebook,Server and workstation
● Graphic Card
● Set Top Box
● Embedded System
n Typical Application
DDR _2.5 V
R2
100KO
C4
0.1 uF
C2
470uF
AT9173 A-SOP 8
1 VIN
VCNTL
8
2 GND
VCNTL
7
3
REFEN
VCNTL
6
4 VOUT VCNTL 5
VCC_ 3.3 V
D D R_VTT
1.25V/ 1.5A
R4
100KO
AT9173A
SOP-8
C8
4. 7uF
C6
470uF
Rev. C.04
1