LM3370_15 Datasheet, PDF (1/33 Pages) Texas Instruments – Dual Synchronous Step-Down DC-DC Converter

LM3370
www.ti.com
SNVS406N – NOVEMBER 2005 – REVISED MAY 2013
LM3370 Dual Synchronous Step-Down DC-DC Converter
with Dynamic Voltage Scaling Function
Check for Samples: LM3370
FEATURES
1
•2 I²C-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 and
Forced PWM Mode for Low Noise Operation
– Spread Spectrum Capability Using I²C
• 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
• 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
• 2.2µH Inductor, 4.7µF Input and 10µF Output
Capacitor Per Channel
• 16-lead WSON Package (4 mm x 5 mm x 0.8
mm)
• 20-Bump DSBGA Package (3.0 mm x 2.0 mm x
0.6 mm)
APPLICATIONS
• Baseband Processors
• Application Processors (Video, Audio)
• I/O Power
• FPGA Power and CPLD
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 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.
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.
Typical Application Circuit
V_IN1
V_IN2
FB1
SDA
SCL
nPOR1
nPOR2
EN1
EN2
FB2
LM3370
V_IN1
C_IN1
4.7 PF
2.7V to 5.5V
SW1
V_OUT1
PGND1 ^{L1:2.2 PH}
SGND
C_OUT1
10 PF
V_DD
PGND2
* ^{4.7 PF}
SW2
V_IN2 ^{L2:2.2 PH}
2.7V to 5.5V
C_IN2
4.7 PF
V_IN1
V_OUT2
C_OUT2
10 PF
* Optional Capacitor
1
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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
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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