LM3370
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SNVS406N –NOVEMBER 2005–REVISED MAY 2013
LM3370 Dual Synchronous Step-Down DC-DC Converter
with Dynamic Voltage Scaling Function
Check for Samples: LM3370
1
FEATURES
APPLICATIONS
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I2C-compatible interface
•
•
•
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Baseband Processors
Application Processors (Video, Audio)
I/O Power
2
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–
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VOUT1 = 1V to 2V in 50 mV Steps
VOUT2 = 1.8V to 3.3V in 100 mV Steps
Automatic PFM/PWM Mode Switching and
Forced PWM Mode for Low Noise Operation
Spread Spectrum Capability Using I2C
FPGA Power and CPLD
DESCRIPTION
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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 600mA load per
channel. The output voltage range varies from 1V to
3.3V and can be dynamically controlled using the I2C-
compatible interface. This dynamic voltage scaling
function allows processors to achieve maximum
performance at the lowest power level. The I2C-
compatible interface can also be used to control auto
PFM-PWM/PWM mode selection and other
performance enhancing features.
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600mA Load Per Channel
2MHz PWM Fixed Switching Frequency (Typ.)
The Bucks Operate 180° Out-of-Phase Timing
Offset for Noise and Input Surge Current
Abatement
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Internal Synchronous Rectification for High
Efficiency
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Internal Soft Start
Power-on-Reset Function for Both Outputs
2.7V ≤ VIN ≤ 5.5V
The LM3370 offers superior features and
performance for portable systems with complex
Operates from a Single Li-Ion Cell or 3 Cell
NiMH/NiCd Batteries and 3.3V/5.5V Fixed Rails
power
management
requirements.
Automatic
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2.2µH Inductor, 4.7µF Input and 10µF Output
Capacitor Per Channel
intelligent switching between PWM low-noise and
PFM low-current mode offers improved system
16-lead WSON Package (4 mm x 5 mm x 0.8
mm)
efficiency.
Internal
synchronous
rectification
enhances the converter efficiency without the use of
further external devices.
20-Bump DSBGA Package (3.0 mm x 2.0 mm x
0.6 mm)
Typical Application Circuit
C
IN1
4.7 mF
V
IN1
2.7V to 5.5V
FB1
SDA
V
OUT1
SW1
L1:2.2 mH
SCL
PGND1
SGND
C
OUT1
10 mF
nPOR1
nPOR2
EN1
V
V
IN1
IN2
LM3370
V
DD
V
IN1
4.7 mF
*
PGND2
SW2
V
OUT2
EN2
L2:2.2 mH
V
IN2
FB2
C
OUT2
10 mF
2.7V to 5.5V
C
IN2
4.7 mF
* Optional Capacitor
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2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2005–2013, Texas Instruments Incorporated