LM27403_15 Datasheet, PDF (1/54 Pages) Texas Instruments – LM27403 Synchronous Buck Controller With Temperature-Compensated, Inductor-DCRBased Overcurrent Protection and Programmable Thermal Shutdown

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LM27403
SNVS896B – AUGUST 2013 – REVISED NOVEMBER 2014
LM27403 Synchronous Buck Controller With Temperature-Compensated, Inductor-DCR-
Based Overcurrent Protection and Programmable Thermal Shutdown
1 Features
•1 Up to 97% Efficiency and 93% Duty Cycle
• Wide Input Voltage Range of 3 V to 20 V
• Switching Frequency From 200 kHz to 1.2 MHz
• Inductor-DCR-Based Overcurrent Protection With
Thermal Compensation
• 0.6-V Reference With 1% Feedback Accuracy
• 30-ns Min On-Time for Low VOUT
• Integrated High-Current MOSFET Drivers
– Adaptive Deadtime Control
• Ultrafast Line and Load Transient Response
– High GBW Error Amplifier
– PWM Line Feedforward
• Integrated VDD Bias Supply LDO Subregulator
• Programmable System-Level OTP
• Precision Enable With Hysteresis
• Frequency Synchronization
• Monotonic Prebiased Start-up
• Programmable Soft-Start With Tracking
• Output Remote Sense
• Open-Drain Power Good Indicator
• 4-mm x 4-mm WQFN-24 PowerPAD™ Package
2 Applications
• DC-DC Converters and POL Modules
• Telecommunications Infrastructure
• Embedded Computing, Servers, Storage
3 Description
The LM27403 is a feature-rich, easy-to-use,
synchronous buck controller offering exceptional
levels of integration and performance for superior
efficiency in high power density, point-of-load (POL)
DC-DC regulator solutions. The resistor-
programmable switching frequency from 200 kHz to
1.2 MHz and integrated, high-current MOSFET gate
drivers with adaptive deadtime offer flexibility to
optimize solution size and maximize conversion
efficiency.
High precision and low output voltage are easily
obtained with a 0.6-V, 1% accurate voltage reference
together with a 30-ns high-side MOSFET minimum
controllable on-time. Using lossless inductor dc
resistance (DCR) current sensing and an inexpensive
2N3904 BJT to sense temperature remotely at the
inductor, the LM27403 supports accurate and
thermally compensated overcurrent protection (OCP).
Device Information⁽¹⁾
PART NUMBER PACKAGE
BODY SIZE (NOM)
LM27403
WQFN (24)
4.00 mm x 4.00 mm
(1) For all available packages, see the orderable addendum at
the end of the datasheet.
Typical Application Diagram
VOUT+
VDD _VIN
24 23
1 SS/TRACK
2 RS
3 FB
4 COMP
LM27403
5 FADJ
6 SYNC
CBOOT 18
HG 17
SW ¹⁶
LG 15
VDD ¹⁴
GND 13
7 8 9 10 11 12
VIN
GND
VOUT+
D± D+
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.