LM2696 - 3A, Constant On Time Buck Regulator

Datasheet	Packaging	Samples & Pricing	Eval. Boards	Reliability	Application Notes	Knowledge Base

Features

•	Input voltage range of 4.5V–24V
•	Constant On-Time
•	No compensation needed
•	Maximum Load Current of 3A
•	Switching frequency of 100 kHz–500 kHz
•	Constant frequency across input range
•	TTL compatible shutdown thresholds
•	Low standby current of 12 µA
•	130 mΩ internal MOSFET switch

General Description

The LM2696 is a pulse width modulation (PWM) buck regulator capable of delivering up to 3A into a load. More...

Applications

•	High efficiency step-down switching regulators
•	LCD Monitors
•	Set-Top Boxes

Typical Application

click for larger image

Parameters Values

Output Current 3000 mA

Input Min Voltage 4.5 Volt

Input Max Voltage 24 Volt

Output Min 1.254 Volt

Output Max 20 Volt

Frequency Min 100 kHz

Frequency Max 500 kHz

Efficiency (peak) 90 %

On/Off Pin Yes

Error Flag Yes

SoftStart Yes

Sync Pin No

Inverting Yes

Flyback No

RegType Switching Regulator

Temperature Min -40 deg C

Temperature Max 125 deg C

Adjustable Output Yes

Adj Switch Frequency Yes

PWM Mode Constant on-time

Topology Buck

Special Features No compensation required, ultra-fast transient response, thermal shutdown

Step-Down Yes

Multiple Output Capability No

Output Power Undefined Watt

Output Voltage Undefined Volt

Output Range 1.254V to 20V

Switching Frequency 500 kHz

Feedback Voltage 1.254 Volt

Regulator Family Undefined

Synchronous Rectification No

WEBENCH Live Simulation!

LM2696
4.50 <=	V in Lower V	<=	V in Upper V	<= 24.00
V out	1.29 <=		V	<= 20.00
I out			A	<= 3.00
Ambient Temperature			°C	<= 100
What are WEBENCH® tools?

Additional Resources

Application Notes

Block Diagram

click for larger image

Datasheet

RoHS Compliance Information	Size in Kbytes	Date
LM2696 3A, Constant On Time Buck Regulator	421 Kbytes	18-May-09	Download
LM2696 3A, Constant On Time Buck Regulator (Japanese)	590 Kbytes

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Package Availability, Models, Samples & Pricing

Part Number

Package

Factory Lead Time

Models

Samples &
Electronic
Orders

Budgetary Pricing

Std
Pack
Size

Package
Marking
Format

Type

Pins

Spec.

MSL
Rating

Peak
Reflow

RoHS
Report

CAD
Symbols

Weeks

Qty

$US each

LM2696EVAL

3A, Constant On Time Buck Regulator

Full production

N/A

$56.30

8 weeks

N/A

LM2696MXA

TSSOP EXP PAD

NOPB
STD

1
1

260
260

RoHS

Download

Full production

N/A

1K+

$1.70

rail
of
92

NSZXYTT
2696
MXA

8 weeks

1000

LM2696MXAX

TSSOP EXP PAD

NOPB

260

RoHS

Download

Full production

N/A

1K+

$1.70

reel
of
2500

NSZXYTT
2696
MXA

6 weeks

10000

General Description

The LM2696 is a pulse width modulation (PWM) buck regulator capable of delivering up to 3A into a load. The control loop utilizes a constant on-time control scheme with input voltage feed forward. This provides a topology that has excellent transient response without the need for compensation. The input voltage feed forward ensures that a constant switching frequency is maintained across the entire V_IN range.

The LM2696 is capable of switching frequencies in the range of 100 kHz to 500 kHz. Combined with an integrated 130 mΩ high side NMOS switch the LM2696 can utilize small sized external components and provide high efficiency. An internal soft-start and power-good flag are also provided to allow for simple sequencing between multiple regulators.

The LM2696 is available with an adjustable output in an exposed pad TSSOP-16 package.

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM2696MXA	ABCD150	0	34175	0	0	4234000	1	1201409060
LM2696MXAX	ABCD150	0	34175	0	0	4234000	1	1201409060

Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR. The Long Term Failure Rates were calculated at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress temperature of 150°C to an application temperature of 55°C.

For more information on Reliability Metrics, please click here.

Application Notes

Title	Size in Kbytes	Date
AN-1410: Application Note 1410 LM2696 Demonstration Board	566 Kbytes	14-Aug-06	Download
AN-1410 (Chinese): Application Note 1410 LM2696 Demonstration Board	314 Kbytes

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More Application Notes

Title	Size in Kbytes	Date
AN-1202: Application Note 1202 LM2698 Demoboard	217 Kbytes	10-May-04	Download
AN-1444: Application Note 1444 LM2695 Evaluation Board	716 Kbytes	15-Feb-06	Download
AN-1472: Application Note 1472 LM2694 Evaluation Board	796 Kbytes	16-May-06	Download

If you have trouble printing or viewing PDF file(s), see Printing Problems.

[Information as of 7-Nov-2009]