LM27403 Datasheet, PDF (1/49 Pages) Texas Instruments – Synchronous Buck Controller with Temperature-Compensated, Inductor-DCR-Based Overcurrent Protection and Programmable Thermal Shutdown

LM27403
www.ti.com
SNVS896 A – AUGUST 2013 – REVISED SEPTEMBER 2013
Synchronous Buck Controller with Temperature-Compensated, Inductor-DCR-Based
Overcurrent Protection and Programmable Thermal Shutdown
Check for Samples: LM27403
FEATURES
1
•2 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 Startup with Soft-Start
• Open-Drain Power Good Indicator
• 4 mm x 4 mm, WQFN-24 PowerPAD™ Package
APPLICATIONS
• DC-DC Converters
• High Power Density POL Modules
• Telecommunications Infrastructure
• Embedded Computing, Servers, Storage
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).
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
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
and Power Block NexFET is a trademark of Texas Instruments.
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 © 2013, Texas Instruments Incorporated