XRP2997IDB-F [EXAR]

2A DDR I/II/III Bus Termination Regulator; 2A DDR I / II / III总线终端稳压器


型号：	XRP2997IDB-F
厂家：	EXAR CORPORATION
描述：	2A DDR I/II/III Bus Termination Regulator 2A DDR I / II / III总线终端稳压器稳压器双倍数据速率
文件：	总8页 (文件大小：510K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

XRP2997

2A DDR I/II/III Bus Termination Regulator

July 2011

Rev. 1.0.0

GENERAL DESCRIPTION

APPLICATIONS

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.

 DDR I/II/III Memory Termination

 Active Termination Buses

 Audio-Video Equipments

 Video-Graphics Cards

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_REFpin 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

FEATURES

 DDR1, DDR2 and DDR3 Support

 0.75V_TTGeneration

 ±20mV Output Voltage Offset

 2 Amps Continuous Current Sourcing &

Sinking

controlled

sequencing.

implementation

power-up

 1.1V to 5.5V Wide Input Voltage Range

 Adjustable Output Voltage

Built-in

temperature

protections insure safe operation under

source/sink

and

overcurrent,

under-voltage

over-

lockout

 Suspend to RAM(STR), Enable & Soft

Start Functions

abnormal operating conditions.

 Stable with 22µF Ceramic Capacitor

The XRP2997 meets JEDEC SSTL-2, SSTL-18,

HSTL, SCSI-1 and SCSI-3 specifications for

DDR SDRAM memories.

 UVLO, Over Temperature and Over

Current Protections

 Minimal External Components

The XRP2997 is offered in a RoHS compliant,

“green”/halogen free 8-pin Exposed Pad SOIC

package.

 Pin/Function Compatible with SP2996B

 RoHS Compliant “Green”/Halogen Free

8-Pin SOIC Package

TYPICAL APPLICATION DIAGRAM

Fig. 1: XRP2997 DDRIII V_TTApplication Diagram

Exar Corporation

www.exar.com

48720 Kato Road, Fremont CA 94538, USA

Tel. +1 510 668-7000 – Fax. +1 510 668-7001

XRP2997

2A DDR I/II/III Bus Termination Regulator

ABSOLUTE MAXIMUM RATINGS

OPERATING 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.

Operating Temperature Range.................-40°C to +85°C

Thermal Resistance θ_JA...................................... 60°C/W

Thermal Resistance θ_JC...................................... 16°C/W

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

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

Min.

Typ.

Max.

Units

Conditions

Keep V_CNTL≥V_INduring power on and

power off sequences (note 4)

V_IN, Input Voltage Range

1.8/1.5

5.5

1.1

Keep V_CNTL≥V_INduring power on and

power off sequences (note 4)

V_CNTL, Input Voltage Range

3.3

5.5

2.375

V_OUT, Output Voltage

I_OUT= 0mA

V_REF

V_OS, Output Voltage Offset

+20

µA

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

-20

∆V_LOR, Load Regulation

I_Q, Quiescent Current

I_CNTL, Operating Current of V_CNTL

I_REF, Bias Current of V_REF

2.5

µA

V_REF= 1.25V

Source: V_OUT=0.33xV_REF

Sink: V_OUT=0.95xV_IN(note 3)

I_IL, Current Limit

2.4

R_DSCHG, Output Discharge

Resistance

Ω

V_REF=0V, V_OUT=0.3V

Thermal Protection

T_SD, Thermal Shutdown

Temperature

3.3V ≤ V_CNTL≤ 5V, guaranteed by design

(note 4)

160

°C

Thermal Shutdown Hysteresis

Guaranteed by design

Shutdown Specifications

Output ON

V_REF= 0V  1.25V

0.8

V_TRIGGER, Shutdown Threshold

Output OFF

V_REF= 1.25V  0V

0.2

Note 1: V_OSoffset is the voltage measurement defined as V_OUTsubtracted from V_REF

Note 2: Load regulation is measured at constant junction temperature, using pulse testing with a short ON time.

Note 3: Current limit is measured by applying a short duration current pulse.

Note 4: In order to safely operate your system, V_CNTLmust be > V_IN.

2/8

Rev. 1.0.0

XRP2997

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

Pin Number

Description

Power Input Voltage

V_IN

Ground Signal

GND

Exposed Pad

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.

V_REF

5, 7, 8

Output Voltage

V_OUT

Voltage for the driver circuit and all analog blocks

V_CNTL

ORDERING INFORMATION

Temperature

Part Number

Packing

Quantity

Marking

Package

Note 1

Note 2

Range

XRP2997I

YYWWF

XXXXXX

Exposed pad

SOIC-8

RoHS Compliant

Halogen Free

2.5K/Tape & Reel

XRP2997IDB-F/TR

-40°C≤T_A≤+85°C

“YY” = Year – “WW” = Work Week – “L” = Lead Free Indicator - “X” = Lot Number; when applicable.

3/8

Rev. 1.0.0

XRP2997

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. 5: Output Voltage vs. Temperature

Fig. 4: Turn on and turn off vs. Temperature

Fig. 6: Current limit (sourcing) vs. Temperature

Fig. 8: V_IN=1.5V, V_REF=0.75V source response

Fig. 7: Current limit (sinking) vs. Temperature

Fig. 9: V_IN=1.8V, V_REF=0.9V source response

4/8

Rev. 1.0.0

XRP2997

2A DDR I/II/III Bus Termination Regulator

Fig. 11: V_IN=1.5V, V_REF=0.75V sink response

Fig. 10: V_IN=2.5V, V_REF=1.25V sink response

Fig. 15: V_IN=1.8V, V_REF=0.9V source short circuit

Fig. 10: V_IN=2.5V, V_REF=1.25V source response

Fig. 9: V_IN=1.8V, V_REF=0.9V sink response

Fig. 14: V_IN=1.5V, V_REF=0.75V source short circuit

5/8

Rev. 1.0.0

XRP2997

2A DDR I/II/III Bus Termination Regulator

Fig. 12: V_IN=1.5V, V_REF=0.75V sink short circuit

Fig. 11: V_IN=2.5V, V_REF=1.25V source short circuit

Fig. 14: V_IN=2.5V, V_REF=1.25V sink short circuit

Fig. 13: V_IN=1.8V, V_REF=0.9V sink short circuit

exposed pad to a large land area on top layer

of PCB and by using vias to connect the

exposed pad to an interlayer(s) or bottom

layer. All capacitors should be placed as close

as possible to the respective pins.

APPLICATION INFORMATION

AYOUT CONSIDERATIONS

The XRP2997 is offered in the 8-pin exposed-

pad SOIC package in order to facilitate power

dissipation

(heat

dissipation).

Power

dissipation can be maximized by soldering the

6/8

Rev. 1.0.0

XRP2997

2A DDR I/II/III Bus Termination Regulator

PACKAGE SPECIFICATION

8-PIN SOIC EXPOSED

PAD

Unit: mm (inch)

Eject hole, oriented hole and mold mark are optional.

7/8

Rev. 1.0.0

XRP2997

2A DDR I/II/III Bus Termination Regulator

REVISION HISTORY

Revision

Date

Description

07/22/2011

Initial release of datasheet

1.0.0

FOR FURTHER ASSISTANCE

Email:

customersupport@exar.com

Exar Technical Documentation:

http://www.exar.com/TechDoc/default.aspx?

XAR

CORPORATION

EADQUARTERS AND

SALES OFFICES

48720 Kato Road

Fremont, CA 94538 – USA

Tel.: +1 (510) 668-7000

Fax: +1 (510) 668-7030

www.exar.com

NOTICE

EXAR Corporation reserves the right to make changes to the products contained in this publication in order to improve

design, performance or reliability. EXAR Corporation assumes no responsibility for the use of any circuits described herein,

conveys no license under any patent or other right, and makes no representation that the circuits are free of patent

infringement. Charts and schedules contained herein are only for illustration purposes and may vary depending upon a

user’s specific application. While the information in this publication has been carefully checked; no responsibility, however,

is assumed for inaccuracies.

EXAR Corporation does not recommend the use of any of its products in life support applications where the failure or

malfunction of the product can reasonably be expected to cause failure of the life support system or to significantly affect its

safety or effectiveness. Products are not authorized for use in such applications unless EXAR Corporation receives, in

writing, assurances to its satisfaction that: (a) the risk of injury or damage has been minimized; (b) the user assumes all

such risks; (c) potential liability of EXAR Corporation is adequately protected under the circumstances.

Reproduction, in part or whole, without the prior written consent of EXAR Corporation is prohibited.

8/8

Rev. 1.0.0

XRP2997IDB-F [EXAR]

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