LM34910 - High Voltage (40V, 1.25A) Step Down Switching Regulator

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

Features

•	Integrated 40V, N-Channel buck switch
•	Integrated start-up regulator
•	Input Voltage Range: 8V to 36V
•	No loop compensation required
•	Ultra-Fast transient response
•	Operating frequency remains constant with load current and input voltage
•	Maximum Duty Cycle Limited During Start-Up
•	Adjustable output voltage
•	Valley Current Limit At 1.25A
•	Precision internal reference
•	Low bias current
•	Highly efficient operation
•	Thermal shutdown

General Description

The LM34910 Step Down Switching Regulator features all of the functions needed to implement a low cost, efficient, buck bias regulator capable of supplying 1.25A to the load. More...

Applications

•	High Efficiency Point-Of-Load (POL) Regulator
•	Non-Isolated Telecommunication Buck Regulator
•	Secondary High Voltage Post Regulator

Typical Application

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Parameters Values

Output Current 1250 mA

Input Min Voltage 8 Volt

Input Max Voltage 36 Volt

Output Min 2.5 Volt

Output Max 33 Volt

Frequency Min Undefined kHz

Frequency Max 1000 kHz

Efficiency (peak) 92 %

On/Off Pin Yes

Error Flag No

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

Step-Down Yes

Multiple Output Capability No

Output Power Undefined Watt

Output Voltage Undefined Volt

Output Range 2.5V to 33V

Switching Frequency 1000 kHz

Feedback Voltage 2.5 Volt

Regulator Family Undefined

Synchronous Rectification No

WEBENCH Live Simulation!

LM34910
8.00 <=	V in Lower V	<=	V in Upper V	<= 36.00
V out	2.50 <=		V	<= 36.00
I out			A	<= 1.00
Ambient Temperature			°C	<= 100
What are WEBENCH® tools?

Also Recommended

LM34910C▲	The 50V Rated Version Of The Original LM34910 Device. Complete JIT Positioning Material Available
LM5010▲	Up Tp 75V Vin Range

Additional Resources

Design Tools

Application Notes

Connection Diagram

click for larger image

Datasheet

RoHS Compliance Information	Size in Kbytes	Date
LM34910 High Voltage (40V, 1.25A) Step Down Switching Regulator	583 Kbytes	11-Feb-05	Download

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

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

LM34910EVAL

High Voltage (40V, 1.25A) Step Down Switching Regulator

Full production

N/A

$45.00

8 weeks

N/A

LM34910SD

LLP

NOPB
STD

1
1

260
260

RoHS

Download

Full production

N/A

1K+

$1.46

reel
of
1000

NS
UZXYTT
34910SD

8 weeks

5000

LM34910SDX

LLP

NOPB

260

RoHS

Download

Full production

N/A

1K+

$1.46

reel
of
4500

NS
UZXYTT
34910SD

6 weeks

5000

General Description

The LM34910 Step Down Switching Regulator features all of the functions needed to implement a low cost, efficient, buck bias regulator capable of supplying 1.25A to the load. This buck regulator contains a 40V N-Channel Buck Switch, and is available in the thermally enhanced LLP-10 package. The hysteretic regulation scheme requires no loop compensation, results in fast load transient response, and simplifies circuit implementation. The operating frequency remains constant with line and load variations due to the inverse relationship between the input voltage and the on-time. The current limit detection is set at 1.25A. Additional features include: VCC under-voltage lockout, thermal shutdown, gate drive under-voltage lockout, and maximum duty cycle limiter.

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM34910SD	ABCD150XV1	0	3868	0	0	2595000	2	736338335
LM34910SDX	ABCD150XV1	0	3868	0	0	2595000	2	736338335

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.

Design Tools

Title	Size in Kbytes	Date
LM34910 Quick Start Calculator	362 Kbytes	27-Jul-2009	View

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Application Notes

Title	Size in Kbytes	Date
AN-1349: Application Note 1349 LM34910 Evaluation Board	562 Kbytes	18-Nov-04	Download

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More Application Notes

Title	Size in Kbytes	Date
AN-1601: Application Note 1601 LM34917A Evaluation Board	1142 Kbytes	10-Apr-08	Download
AN-1650: Application Note 1650 LM34919 Evaluation Board	338 Kbytes	8-Jun-07	Download
AN-1650 (Chinese): Application Note 1650 LM34919 Evaluation Board	366 Kbytes
AN-1549: Application Note 1549 LM34914 Evaluation Board	319 Kbytes	17-Mar-07	Download

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

[Information as of 8-Nov-2009]