LM27402_15 Datasheet, PDF (1/48 Pages) Texas Instruments – LM27402 High-Performance Synchronous Buck Controller With DCR Current Sensing

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LM27402
SNVS615J – JANUARY 2010 – REVISED JULY 2015
LM27402 High-Performance Synchronous Buck Controller With DCR Current Sensing
1 Features
•1 Wide Input Voltage Range of 3 V to 20 V
• Inductor DCR or Shunt Resistor Based
Overcurrent Protection
• 0.6-V Reference With ±1% FB Accuracy Across
Full –40°C to 125°C Junction Temperature Range
• Switching Frequency from 200 kHz to 1.2 MHz
• Output Voltage as High as 95% of Input Voltage
• Integrated High-Current MOSFET Drivers
• Internal VDD Bias Supply LDO Subregulator
• External Clock Synchronization
• Adjustable Soft-Start With External Capacitor
• Pre-Biased Start-up Capability
• Power Supply Tracking
• Voltage-Mode Control With Line Feedforward
• Open-Drain Power Good Indicator
• Precision Enable With Hysteresis
• HTSSOP-16 and WQFN-16 Packages
2 Applications
• High Current, Low Voltage Supply for FPGA and
ASIC
• General-Purpose, High-Current Buck Converters
• DC-DC Converters and POL Modules
• Telecom, Datacom, Networking, Distributed Power
Architectures
3 Description
The LM27402 is a voltage-mode, synchronous, DC-
DC step-down controller with lossless inductor DCR
current sensing capability. Sensing the inductor
current eliminates the need to add resistive
powertrain elements, which increases overall
efficiency and facilitates accurate, continuous current
sensing. A 0.6-V ±1% voltage reference enables high
accuracy and low voltage capability at the output. An
input operating voltage range of 3 V to 20 V makes
the LM27402 suitable for a large variety of input rails.
The LM27402 voltage-mode control loop incorporates
input voltage feed-forward to maintain stability
throughout the entire input voltage range. The
switching frequency is adjustable from 200 kHz to
1.2 MHz. Dual, high-current, integrated MOSFET
drivers support large Q_G, low R_DS(on) power
MOSFETs. A power good indicator provides power
rail sequencing capability and output fault detection.
An adjustable external soft-start limits inrush current
and provides monotonic output control during start-
up. Other features include external tracking of other
power supplies, integrated LDO bias supply, and
synchronization capability.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
LM27402
WQFN (16)
HTSSOP (16)
4.00 mm × 4.00 mm
5.00 mm × 4.40 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
Typical Application Circuit
VOUT+
VDD
VIN
SS/TRACK
CBOOT
FB
HG
COMP _LM27402
SW
FADJ
LG
SYNC
GND
VIN
GND
VOUT+
VOUT±
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.