X RP 2 9 9 7
2A DDR I/II/III Bus Termination Regulator
July 2011
Rev. 1.0.0
GENERAL DESCRIPTION
The XRP2997 is a Double Data Rate (DDR)
termination voltage regulator supporting all
power requirements of DDR I, II and III
memories and is capable of sinking or sourcing
2A continuously.
Tightly regulating its output voltage within
±20mV, the XRP2997 converts input voltages
as low as 1.1V while the output voltage is
adjustable through an external resistor divider
or by forcing the V
REF
pin voltage. It maintains
a fast line and load transient response and
only requires an output capacitance of 22µF to
operate. An enable function via an external
MOSFET and a soft start feature allow for a
controlled
implementation
of
power-up
sequencing.
Built-in
source/sink
overcurrent,
over-
temperature
and
under-voltage
lockout
protections insure safe operation under
abnormal operating conditions.
The XRP2997 meets JEDEC SSTL-2, SSTL-18,
HSTL, SCSI-1 and SCSI-3 specifications for
DDR SDRAM memories.
The XRP2997 is offered in a RoHS compliant,
“green”/halogen free 8-pin Exposed Pad SOIC
package.
APPLICATIONS
DDR I/II/III Memory Termination
Active Termination Buses
Audio-Video Equipments
Video-Graphics Cards
FEATURES
DDR1, DDR2 and DDR3 Support
0.75V
TT
Generation
±20mV Output Voltage Offset
2 Amps Continuous Current Sourcing &
Sinking
1.1V to 5.5V Wide Input Voltage Range
Adjustable Output Voltage
Suspend to RAM(STR), Enable & Soft
Start Functions
Stable with 22µF Ceramic Capacitor
UVLO, Over Temperature and Over
Current Protections
Minimal External Components
Pin/Function Compatible with SP2996B
RoHS Compliant “Green”/Halogen Free
8-Pin SOIC Package
TYPICAL APPLICATION DIAGRAM
Fig. 1: XRP2997 DDRIII V
TT
Application Diagram
Exar Corporation
48720 Kato Road, Fremont CA 94538, USA
www.exar.com
Tel. +1 510 668-7000 – Fax. +1 510 668-7001
X RP 2 9 9 7
2A DDR I/II/III Bus Termination Regulator
ABSOLUTE MAXIMUM RATINGS
These are stress ratings only and functional operation of
the device at these ratings or any other above those
indicated in the operation sections of the specifications
below is not implied. Exposure to absolute maximum
rating conditions for extended periods of time may affect
reliability.
V
IN
, V
REF
, V
CNTL
.......................................... -0.3V to 6.0V
Junction Temperature Range.................. -40°C to +150°C
Storage Temperature ............................ -65°C to +150°C
Lead Temperature (Soldering, 10 sec) ................... 260°C
OPERATING RATINGS
Operating Temperature Range ................. -40°C to +85°C
Thermal Resistance
θ
JA
...................................... 60°C/W
Thermal Resistance
θ
JC
...................................... 16°C/W
ELECTRICAL SPECIFICATIONS
Specifications are for an Operating Ambient Temperature of T
A
= 25°C only; limits applying over the full Operating Junction
Temperature range are denoted by a “•”. Minimum and Maximum limits are guaranteed through test, design, or statistical
correlation. Typical values represent the most likely parametric norm at T
A
= 25°C, and are provided for reference purposes
only. Unless otherwise indicated, V
IN
= 1.8V/1.5V, V
CNTL
= 3.3V, V
REF
= 0.5xV
IN
, C
OUT
= 22µF (ceramic), T
A
= 25°C.
Parameter
V
IN
, Input Voltage Range
V
CNTL
, Input Voltage Range
V
OUT
, Output Voltage
V
OS
, Output Voltage Offset
∆V
LOR
, Load Regulation
I
Q
, Quiescent Current
I
CNTL
, Operating Current of V
CNTL
I
REF
, Bias Current of V
REF
I
IL
, Current Limit
R
DSCHG
, Output Discharge
Resistance
Thermal Protection
T
SD
, Thermal Shutdown
Temperature
Thermal Shutdown Hysteresis
Shutdown Specifications
0.8
V
TRIGGER
, Shutdown Threshold
0.2
Note
Note
Note
Note
1:
2:
3:
4:
V
Output ON
V
REF
= 0V
1.25V
Output OFF
V
REF
= 1.25V
0V
160
30
°C
°C
3.3V
≤
V
CNTL
≤
5V, guaranteed by design
(note 4)
Guaranteed by design
0
2.4
3
18
25
-20
-20
-20
2
1
Min.
1.1
2.375
Typ.
1.8/1.5
3.3
V
REF
+20
+20
+20
90
2.5
1
Max.
5.5
5.5
Units
V
V
V
mV
mV
mV
µA
mA
µA
A
Ω
Conditions
Keep V
CNTL
≥V
IN
during power on and
power off sequences (note 4)
Keep V
CNTL
≥V
IN
during power on and
power off sequences (note 4)
I
OUT
= 0mA
I
OUT
= 0mA (note 1)
I
OUT
= 0.1mA to +2A
I
OUT
= 0.1mA to -2A
V
REF
< 0.2V, V
OUT
= OFF
I
OUT
= 0mA
V
REF
= 1.25V
Source: V
OUT
=0.33xV
REF
Sink: V
OUT
=0.95xV
IN
(note 3)
V
REF
=0V, V
OUT
=0.3V
V
OS
offset is the voltage measurement defined as V
OUT
subtracted from V
REF
.
Load regulation is measured at constant junction temperature, using pulse testing with a short ON time.
Current limit is measured by applying a short duration current pulse.
In order to safely operate your system, V
CNTL
must be > V
IN
.
© 2011 Exar Corporation
2/8
Rev. 1.0.0
X RP 2 9 9 7
2A DDR I/II/III Bus Termination Regulator
BLOCK DIAGRAM
Fig. 2: XRP2997 Block Diagram
PIN ASSIGNMENT
Fig. 3: XRP2997 Pin Assignment
PIN DESCRIPTION
Name
V
IN
GND
V
REF
V
OUT
NC
V
CNTL
Pin Number
1
2
Exposed Pad
3
4
5, 7, 8
6
Power Input Voltage
Ground Signal
Reference Input Voltage.
This input can also be used as an enable signal; pulling this pin low shuts down the
XRP2997. Refer to typical application circuit.
Output Voltage
NC
Voltage for the driver circuit and all analog blocks
Description
ORDERING INFORMATION
Part Number
XRP2997IDB-F/TR
Temperature
Range
-40°C≤T
A
≤+85°C
Marking
XRP2997I
YYWWF
XXXXXX
Package
Packing
Quantity
Note 1
Note 2
Exposed pad
2.5K/Tape & Reel RoHS Compliant
SOIC-8
Halogen Free
“YY” = Year – “WW” = Work Week – “L” = Lead Free Indicator - “X” = Lot Number; when applicable.
© 2011 Exar Corporation
3/8
Rev. 1.0.0
X RP 2 9 9 7
2A DDR I/II/III Bus Termination Regulator
TYPICAL PERFORMANCE CHARACTERISTICS
All data taken at V
IN
= 1.8V/1.5V, V
CNTL
= 3.3V, V
REF
= 0.5xV
IN
, C
OUT
= 22µF (ceramic), T
A
= 25°C, unless otherwise specified
- Schematic and BOM from Application Information section of this datasheet.
Fig. 4: Turn on and turn off vs. Temperature
Fig. 5: Output Voltage vs. Temperature
Fig. 6: Current limit (sourcing) vs. Temperature
Fig. 7: Current limit (sinking) vs. Temperature
Fig. 8: V
IN
=1.5V, V
REF
=0.75V source response
Fig. 9: V
IN
=1.8V, V
REF
=0.9V source response
© 2011 Exar Corporation
4/8
Rev. 1.0.0
X RP 2 9 9 7
2A DDR I/II/III Bus Termination Regulator
Fig. 10: V
IN
=2.5V, V
REF
=1.25V source response
Fig. 11: V
IN
=1.5V, V
REF
=0.75V sink response
Fig. 9: V
IN
=1.8V, V
REF
=0.9V sink response
Fig. 10: V
IN
=2.5V, V
REF
=1.25V sink response
Fig. 14: V
IN
=1.5V, V
REF
=0.75V source short circuit
Fig. 15: V
IN
=1.8V, V
REF
=0.9V source short circuit
© 2011 Exar Corporation
5/8
Rev. 1.0.0
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