LM3370 - Dual Synchronous Step-Down DC-DC Converter with Dynamic Voltage Scaling Function from the PowerWise® Family

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

Features
•I 2C compatible interface
•VOUT1 = 1V to 2V in 50 mV steps
•VOUT2 = 1.8V to 3.3V in 100 mV steps
•Automatic PFM/PWM mode switching & Forced PWM mode for low noise operation
•Spread Spectrum capability using I 2C
•600 mA load per channel
•2 MHz PWM fixed switching frequency (typ.)
•Internal synchronous rectification for high efficiency
•Internal soft start
•Power-on-reset function for both outputs
•2.7V ≤ VIN ≤ 5.5V
•Operates from a single Li-Ion cell or 3 cell NiMH/NiCd batteries and 3.3V/5.5V fixed rails
•2.2 µH Inductor, 4.7 µF Input and 10 µF Output Capacitor per channel
•16-lead LLP Package (4 mm x 5 mm x 0.8 mm)
•20-Bump micro SMD Package (3.0 mm x 2.0 mm x 0.6 mm)

General Description

The LM3370 is a dual step-down DC-DC converter optimized for powering ultra-low voltage circuits from a single Li-Ion battery and input rail ranging from 2.7V to 5.5V. More...


Applications

•Baseband Processors
•Application Processors (Video, Audio)
•I/O Power
•FPGA Power and CPLD
  Typical Application
click for larger image


Parametric Table     expand
Parametric Table    collapse
Channels 2 Channels
Output Range 1V-3.3V, 1V to 2V for buck 1; 1.8V to 3.3V for buck 2
Output1 Topology Buck
Output2 Topology Buck
Input Min Voltage 2.7 Volt
Input Max Voltage 5.5 Volt
Frequency Min 2000, 1500 kHz
Frequency Max 2400, 2000 kHz
Efficiency (peak) 90 %
Channels 2 Channels
Output Range 1V-3.3V, 1V to 2V for buck 1; 1.8V to 3.3V for buck 2
Output1 Topology Buck
Output2 Topology Buck
Input Min Voltage 2.7 Volt
Input Max Voltage 5.5 Volt
Frequency Min 2000, 1500 kHz
Frequency Max 2400, 2000 kHz
Efficiency (peak) 90 %
Adj Switch Frequency No, Yes
Output1 VoutMin 1 Volt
Output1 VoutMax 2 Volt
Output1 IoutMax 600 mA
Output2 VoutMin 1.8, 2 Volt
Output2 VoutMax 3.3 Volt
Output2 IoutMax 600 mA
Sync Pin No
MOSFET Rdson NFET 0.24ohm, PFET 0.39ohm
SoftStart Yes
On/Off Pin Yes
Error Flag No
Special Features I2C interface, Dynamic Voltage Scaling
Topology Buck, Voltage Mode
RegType Switching Regulator
Step-Down Yes
Step-Up No
Inverting No
Flyback No
Switching Frequency 2000 kHz
Multiple Output Capability Yes
Temperature Min -30 deg C
Temperature Max 85 deg C
PowerWise Yes
View Using Catalog


Typical Performance

click for larger image


  Additional Resources
Design Tools (see below)


Block Diagram

click for larger image



Datasheet
RoHS Compliance Information Size in KbytesDate Click link below to Download
LM3370 Dual Synchronous Step-Down DC-DC Converter with Dynamic Voltage Scaling Function 5414 Kbytes 4-Jan-08 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
I2C-CPEVUSB I2C Interface BoardFull productionN/A
 
Buy Now 		 CALLN/A-
6 weeksN/A
LM3370TL-3008EVLM3370 (micro SMD) Dual Synchronous Regulator with Dynamic Voltage Scaling Evaluation BoardFull productionN/A
 
Buy Now 		 CALLN/A-
6 weeksN/A
LM3370SD-3021EVLM3370 (LLP) Dual Synchronous Regulator with Dynamic Voltage Scaling Evaluation BoardFull productionN/A
 
Buy Now 		1+$60.001-
6 weeksN/A
LM3370SD-3013LLP16NOPB1260RoHS Download Full productionN/A
Samples
Buy Now 		1K+$1.35reel
of
1000		NS
UZXYTT
S0003UB
6 weeksN/A
LM3370SD-3416LLP16NOPB1260RoHS Download Full productionN/A
Samples
Buy Now 		1K+$1.35reel
of
1000		NS
UZXYTT
S0003VB
6 weeksN/A
LM3370SD-3621LLP16NOPB1260RoHS Download Full productionN/A
Samples
Buy Now 		1K+$1.35reel
of
1000		NS
UZXYTT
S0004AB
6 weeksN/A
LM3370SD-3806LLP16NOPB1260RoHS Download Full productionN/A
Samples
Buy Now 		1K+$1.35reel
of
1000		NS
UZXYTT
S0003XB
12 weeksN/A
LM3370SD-4221LLP16NOPB1260RoHS Download Full productionN/A
Samples
Buy Now 		1K+$1.35reel
of
1000		NS
UZXYTT
S0003YB
6 weeksN/A
LM3370SD-3021LLP16NOPB1260RoHS Download Full productionN/A
Samples
Buy Now 		1K+$1.35reel
of
1000		NS
UZXYTT
S0003TB
6 weeks50
LM3370SDX-3013LLP16NOPB1260RoHS Download Full productionN/A
 
Buy Now 		1K+$1.35reel
of
4500		NS
UZXYTT
S0003UB
6 weeksN/A
LM3370SDX-3416LLP16NOPB1260RoHS Download Full productionN/A
 
Buy Now 		1K+$1.35reel
of
4500		NS
UZXYTT
S0003VB
6 weeksN/A
LM3370SDX-3621LLP16NOPB1260RoHS Download Full productionN/A
 
Buy Now 		1K+$1.35reel
of
4500		NS
UZXYTT
S0004AB
12 weeksN/A
LM3370SDX-3806LLP16NOPB1260RoHS Download Full productionN/A
 
Buy Now 		1K+$1.35reel
of
4500		NS
UZXYTT
S0003XB
6 weeksN/A
LM3370SDX-4221LLP16NOPB1260RoHS Download Full productionN/A
 
Buy Now 		1K+$1.35reel
of
4500		NS
UZXYTT
S0003YB
6 weeksN/A
LM3370SDX-3021LLP16NOPB1260RoHS Download Full productionN/A
 
Buy Now 		1K+$1.35reel
of
4500		NS
UZXYTT
S0003TB
6 weeksN/A
LM3370TL-3006MICRO SMD20NOPB1260RoHS Download Full productionN/A
Samples
Buy Now 		1K+$1.35reel
of
250		XYTT
I SPUB
6 weeksN/A
LM3370TL-3008MICRO SMD20NOPB1260RoHS Download Full productionN/A
Samples
Buy Now 		1K+$1.35reel
of
250		XYTT
I SPTB
6 weeksN/A
LM3370TL-3022MICRO SMD20NOPB1260RoHS Download Full productionN/A
Samples
Buy Now 		1K+$1.35reel
of
250		XYTT
I STHB
6 weeksN/A
LM3370TL-3206MICRO SMD20NOPB1260RoHS Download Full productionN/A
Samples
Buy Now 		1K+$1.35reel
of
250		XYTT
I SPXB
6 weeksN/A
LM3370TL-3607MICRO SMD20NOPB1260RoHS Download Full productionN/A
Samples
Buy Now 		1K+$1.35reel
of
250		XYTT
I SPSB
6 weeksN/A
LM3370TL-3806MICRO SMD20NOPB1260RoHS Download Full productionN/A
Samples
Buy Now 		1K+$1.35reel
of
250		XYTT
I SPVB
6 weeksN/A
LM3370TLX-3006MICRO SMD20NOPB1260RoHS Download Full productionN/A
 
Buy Now 		1K+$1.35reel
of
3000		XYTT
I SPUB
6 weeksN/A
LM3370TLX-3008MICRO SMD20NOPB1260RoHS Download Full productionN/A
 
Buy Now 		1K+$1.35reel
of
3000		XYTT
I SPTB
6 weeksN/A
LM3370TLX-3022MICRO SMD20NOPB1260RoHS Download Full productionN/A
 
Buy Now 		1K+$1.35reel
of
3000		XYTT
I STHB
6 weeksN/A
LM3370TLX-3206MICRO SMD20NOPB1260RoHS Download Full productionN/A
 
Buy Now 		1K+$1.35reel
of
3000		XYTT
I SPXB
6 weeksN/A
LM3370TLX-3607MICRO SMD20NOPB1260RoHS Download Full productionN/A
 
Buy Now 		1K+$1.35reel
of
3000		XYTT
I SPSB
6 weeksN/A
LM3370TLX-3806MICRO SMD20NOPB1260RoHS Download Full productionN/A
 
Buy Now 		1K+$1.35reel
of
3000		XYTT
I SPVB
6 weeksN/A

General Description

The LM3370 is a dual step-down DC-DC converter optimized for powering ultra-low voltage circuits from a single Li-Ion battery and input rail ranging from 2.7V to 5.5V. It provides two outputs with 600 mA load per channel. The output voltage range varies from 1V to 3.3V and can be dynamically controlled using the I 2C compatible interface. This dynamic voltage scaling function allows processors to achieve maximum performance at the lowest power level. The I 2C compatible interface can also be used to control auto PFM-PWM/PWM mode selection and other performance enhancing features.

The LM3370 offers superior features and performance for portable systems with complex power management requirements. Automatic intelligent switching between PWM low-noise and PFM low-current mode offers improved system efficiency. Internal synchronous rectification enhances the converter efficiency without the use of further external devices.

There is a power-on-reset function that monitors the level of the output voltage to avoid unexpected power losses. The independent enable pin for each output allows for simple and effective power sequencing.

LM3370 is available in a 4 mm by 5 mm 16-lead non-pullback LLP and a 20-Bump micro SMD, 3.0 mm x 2.0 mm x 0.6 mm, package. A high switching frequency—2 MHz (typ)—allows use of tiny surface-mount components including a 2.2 µH inductor.

Default fixed voltages for the 2 output voltages combination can be customized to fit system requirements by contacting National Semiconductor Corporation.

Reliability Metrics

Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
LM3370SD-3013CMOS7016561009540004270700104
LM3370SD-3021CMOS7016561009540004270700104
LM3370SD-3416CMOS7016561009540004270700104
LM3370SD-3621CMOS7016561009540004270700104
LM3370SD-3806CMOS7016561009540004270700104
LM3370SD-4221CMOS7016561009540004270700104
LM3370SDX-3013CMOS7016561009540004270700104
LM3370SDX-3021CMOS7016561009540004270700104
LM3370SDX-3416CMOS7016561009540004270700104
LM3370SDX-3621CMOS7016561009540004270700104
LM3370SDX-3806CMOS7016561009540004270700104
LM3370SDX-4221CMOS7016561009540004270700104
LM3370TL-3006CMOS7016561009540004270700104
LM3370TL-3008CMOS7016561009540004270700104
LM3370TL-3022CMOS7016561009540004270700104
LM3370TL-3206CMOS7016561009540004270700104
LM3370TL-3607CMOS7016561009540004270700104
LM3370TL-3806CMOS7016561009540004270700104
LM3370TLX-3006CMOS7016561009540004270700104
LM3370TLX-3008CMOS7016561009540004270700104
LM3370TLX-3022CMOS7016561009540004270700104
LM3370TLX-3206CMOS7016561009540004270700104
LM3370TLX-3607CMOS7016561009540004270700104
LM3370TLX-3806CMOS7016561009540004270700104

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    
Efficiency and Size: Challenges in Power Management for Portable Devices     View    

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Application Notes

TitleSize in Kbytes Date Click link below to Download
AN-1428: Application Note 1428 LM3370 Evaluation Board 11933 Kbytes 9-Jan-08 Download
AN-1428 (Chinese): Application Note 1428 LM3370 Evaluation Board
 901 Kbytes  
AN-1840: Application Note 1840 USB I 2 C Interface Board Reference Manual 2769 Kbytes 30-Apr-08 Download

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

[Information as of 3-Jul-2009]