LM3370 - Dual Synchronous Step-Down DC-DC Converter with Dynamic Voltage Scaling Function

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
•	V_OUT1 = 1V to 2V in 50 mV steps
•	V_OUT2 = 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 ≤ V_IN ≤ 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

Parameters Values

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

Typical Performance

click for larger image

Additional Resources

Block Diagram

click for larger image

Datasheet

RoHS Compliance Information	Size in Kbytes	Date
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 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

Qty

Qty

$US each

I2C-CPEV

USB I2C Interface Board

Full production

N/A

Buy Now

N/A

6 weeks

N/A

LM3370TL-3008EV

LM3370 (micro SMD) Dual Synchronous Regulator with Dynamic Voltage Scaling Evaluation Board

Full production

N/A

Buy Now

N/A

6 weeks

N/A

LM3370SD-3021EV

LM3370 (LLP) Dual Synchronous Regulator with Dynamic Voltage Scaling Evaluation Board

Full production

N/A

Buy Now

1+

$60.00

1

6 weeks

N/A

LM3370SD-3013

16

NOPB

1

260

Full production

N/A

Samples

Buy Now

1K+

$1.35

reel
of
1000

NS
UZXYTT
S0003UB

6 weeks

N/A

LM3370SD-3416

16

NOPB

1

260

Full production

N/A

Samples

Buy Now

1K+

$1.35

reel
of
1000

NS
UZXYTT
S0003VB

6 weeks

N/A

LM3370SD-3621

16

NOPB

1

260

Full production

N/A

Samples

Buy Now

1K+

$1.35

reel
of
1000

NS
UZXYTT
S0004AB

6 weeks

N/A

LM3370SD-3806

16

NOPB

1

260

Full production

N/A

Samples

Buy Now

1K+

$1.35

reel
of
1000

NS
UZXYTT
S0003XB

12 weeks

N/A

LM3370SD-4221

16

NOPB

1

260

Full production

N/A

Samples

Buy Now

1K+

$1.35

reel
of
1000

NS
UZXYTT
S0003YB

6 weeks

N/A

LM3370SD-3021

16

NOPB

1

260

Full production

N/A

Samples

Buy Now

1K+

$1.35

reel
of
1000

NS
UZXYTT
S0003TB

6 weeks

50

LM3370SDX-3013

16

NOPB

1

260

Full production

N/A

Buy Now

1K+

$1.35

reel
of
4500

NS
UZXYTT
S0003UB

6 weeks

N/A

LM3370SDX-3416

16

NOPB

1

260

Full production

N/A

Buy Now

1K+

$1.35

reel
of
4500

NS
UZXYTT
S0003VB

6 weeks

N/A

LM3370SDX-3621

16

NOPB

1

260

Full production

N/A

Buy Now

1K+

$1.35

reel
of
4500

NS
UZXYTT
S0004AB

12 weeks

N/A

LM3370SDX-3806

16

NOPB

1

260

Full production

N/A

Buy Now

1K+

$1.35

reel
of
4500

NS
UZXYTT
S0003XB

6 weeks

N/A

LM3370SDX-4221

16

NOPB

1

260

Full production

N/A

Buy Now

1K+

$1.35

reel
of
4500

NS
UZXYTT
S0003YB

6 weeks

N/A

LM3370SDX-3021

16

NOPB

1

260

Full production

N/A

Buy Now

1K+

$1.35

reel
of
4500

NS
UZXYTT
S0003TB

6 weeks

N/A

LM3370TL-3006

20

NOPB

1

260

Full production

N/A

Samples

Buy Now

1K+

$1.35

reel
of
250

6 weeks

N/A

LM3370TL-3008

20

NOPB

1

260

Full production

N/A

Samples

Buy Now

1K+

$1.35

reel
of
250

6 weeks

N/A

LM3370TL-3022

20

NOPB

1

260

Full production

N/A

Samples

Buy Now

1K+

$1.35

reel
of
250

6 weeks

N/A

LM3370TL-3206

20

NOPB

1

260

Full production

N/A

Samples

Buy Now

1K+

$1.35

reel
of
250

6 weeks

N/A

LM3370TL-3607

20

NOPB

1

260

Full production

N/A

Samples

Buy Now

1K+

$1.35

reel
of
250

6 weeks

N/A

LM3370TL-3806

20

NOPB

1

260

Full production

N/A

Samples

Buy Now

1K+

$1.35

reel
of
250

6 weeks

N/A

LM3370TLX-3006

20

NOPB

1

260

Full production

N/A

Buy Now

1K+

$1.35

reel
of
3000

6 weeks

N/A

LM3370TLX-3008

20

NOPB

1

260

Full production

N/A

Buy Now

1K+

$1.35

reel
of
3000

6 weeks

N/A

LM3370TLX-3022

20

NOPB

1

260

Full production

N/A

Buy Now

1K+

$1.35

reel
of
3000

6 weeks

N/A

LM3370TLX-3206

20

NOPB

1

260

Full production

N/A

Buy Now

1K+

$1.35

reel
of
3000

6 weeks

N/A

LM3370TLX-3607

20

NOPB

1

260

Full production

N/A

Buy Now

1K+

$1.35

reel
of
3000

6 weeks

N/A

LM3370TLX-3806

20

NOPB

1

260

Full production

N/A

Buy Now

1K+

$1.35

reel
of
3000

6 weeks

N/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-3013	CMOS7	0	18406	0	0	1089000	4	309006723
LM3370SD-3021	CMOS7	0	18406	0	0	1089000	4	309006723
LM3370SD-3416	CMOS7	0	18406	0	0	1089000	4	309006723
LM3370SD-3621	CMOS7	0	18406	0	0	1089000	4	309006723
LM3370SD-3806	CMOS7	0	18406	0	0	1089000	4	309006723
LM3370SD-4221	CMOS7	0	18406	0	0	1089000	4	309006723
LM3370SDX-3013	CMOS7	0	18406	0	0	1089000	4	309006723
LM3370SDX-3021	CMOS7	0	18406	0	0	1089000	4	309006723
LM3370SDX-3416	CMOS7	0	18406	0	0	1089000	4	309006723
LM3370SDX-3621	CMOS7	0	18406	0	0	1089000	4	309006723
LM3370SDX-3806	CMOS7	0	18406	0	0	1089000	4	309006723
LM3370SDX-4221	CMOS7	0	18406	0	0	1089000	4	309006723
LM3370TL-3006	CMOS7	0	18406	0	0	1089000	4	309006723
LM3370TL-3008	CMOS7	0	18406	0	0	1089000	4	309006723
LM3370TL-3022	CMOS7	0	18406	0	0	1089000	4	309006723
LM3370TL-3206	CMOS7	0	18406	0	0	1089000	4	309006723
LM3370TL-3607	CMOS7	0	18406	0	0	1089000	4	309006723
LM3370TL-3806	CMOS7	0	18406	0	0	1089000	4	309006723
LM3370TLX-3006	CMOS7	0	18406	0	0	1089000	4	309006723
LM3370TLX-3008	CMOS7	0	18406	0	0	1089000	4	309006723
LM3370TLX-3022	CMOS7	0	18406	0	0	1089000	4	309006723
LM3370TLX-3206	CMOS7	0	18406	0	0	1089000	4	309006723
LM3370TLX-3607	CMOS7	0	18406	0	0	1089000	4	309006723
LM3370TLX-3806	CMOS7	0	18406	0	0	1089000	4	309006723

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

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Application Notes

Title	Size in Kbytes	Date
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

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[Information as of 7-Nov-2009]