LM34914 - Ultra Small 1.25A Step-Down Switching Regulator with Intelligent Current Limit
Datasheet Packaging Samples & Pricing Eval. Boards Reliability Design Tools Application Notes Knowledge Base

Features
Input Voltage Range: 8V to 40V
Integrated N-Channel buck switch
Valley current limit varies with VIN and VOUT to reduce excessive inductor current
On-time is reduced when in current limit
Integrated start-up regulator
No loop compensation required
Ultra-Fast transient response
Maximum switching frequency: 1.3 MHz
Operating frequency remains nearly constant with load current and input voltage variations
Programmable soft-start
Precision internal reference
Adjustable output voltage
Thermal shutdown

General Description


The LM34914 Step-Down Switching Regulator features all the functions needed to implement a low cost, efficient, buck bias regulator capable of supplying at least 1.25A to the load. More...


  Typical Application
*click for larger image


ParametersValues
Output Current 1250 mA
Input Min Voltage 8 Volt
Input Max Voltage 40 Volt
Output Min 2.5 Volt
Output Max 37 Volt
Frequency Min Undefined kHz
Frequency Max 1300 kHz
Efficiency (peak) 94.5 %
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 37V
Switching Frequency 1300 kHz
Feedback Voltage 2.5 Volt
Regulator Family Undefined
Automotive Yes
Synchronous Rectification No


Typical Performance


*click for larger image


  Additional Resources
Design Tools

Application Notes


Block Diagram


*click for larger image



Datasheet
RoHS Compliance Information Size in KbytesDate Click link below to Download
LM34914 Ultra Small 1.25A Step-Down Switching Regulator with Intelligent Current Limit 328
Kbytes
20-Dec-07 Download

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


Package Availability, Models, Samples & Pricing
Part NumberPackageFactory Lead TimeModelsSamples &
Electronic
Orders
Budgetary PricingStd
Pack
Size
Package
Marking
Format
TypePinsSpec.MSL
Rating
Peak
Reflow
RoHS
Report
CAD
Symbols
WeeksQtyQty$US each
LM34914EVALUltra Small 1.25A Step-Down Switching Regulator with Intelligent Current LimitFull productionN/A
 
Buy Now
1+$31.501-
8 weeksN/A
LM34914SDLLP10NOPB1260RoHS N/A Full productionN/A
Samples
Buy Now
1K+$1.30reel
of
1000
ZXYTT
34914
6 weeksN/A
LM34914SDXLLP10NOPB1260RoHS N/A Full productionN/A
 
Buy Now
1K+$1.30reel
of
4500
ZXYTT
34914
6 weeksN/A

General Description


The LM34914 Step-Down Switching Regulator features all the functions needed to implement a low cost, efficient, buck bias regulator capable of supplying at least 1.25A to the load. To reduce excessive switch current due to the possibility of a saturating inductor the valley current limit threshold changes with input and output voltages, and the on-time is reduced when current limit is detected. This buck regulator contains a 44V N-Channel Buck Switch, and is available in the thermally enhanced 3 mm x 3 mm LLP-10 package. The feedback 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 valley current limit results in a smooth transition from constant voltage to constant current mode when current limit is detected, reducing the frequency and output voltage, without the use of foldback. Additional features include: VCC under-voltage lock-out, thermal shutdown, gate drive under-voltage lock-out, and maximum duty cycle limit.

Reliability Metrics


Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
LM34914SDABCD15003417500423400011201409060
LM34914SDXABCD15003417500423400011201409060

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


TitleSize in Kbytes Date Click link below to Download    
LM34914 Quick Start Calculator 367 Kbytes 30-Jul-2009 View    

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

Application Notes


TitleSize in Kbytes Date Click link below to Download
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.

More Application Notes


TitleSize in Kbytes Date Click link below to Download
AN-1349: Application Note 1349 LM34910 Evaluation Board 562
Kbytes
18-Nov-04 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-1601: Application Note 1601 LM34917A Evaluation Board 1142
Kbytes
10-Apr-08 Download

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

[Information as of 8-Nov-2009]