LM3478MA_15 Datasheet, PDF (1/26 Pages) Texas Instruments – High-Efficiency Low-Side N-Channel Controller for Switching Regulator

LM3478MA
www.ti.com
SNVS705B – FEBRUARY 2011 – REVISED FEBRUARY 2013
High-Efficiency Low-Side N-Channel Controller for Switching Regulator
Check for Samples: LM3478MA
FEATURES
1
•2 8-lead SOIC package
• Internal push-pull driver with 1A peak current
capability
• Current limit and thermal shutdown
• Frequency compensation optimized with a
capacitor and a resistor
• Internal soft start
• Current Mode Operation
• Undervoltage Lockout with hysteresis
APPLICATIONS
• Distributed Power Systems
• Battery Chargers
• Offline Power Supplies
• Telecom Power Supplies
• Automotive Power Systems
KEY SPECIFICATIONS
• Wide supply voltage range of 2.97V to 40V
• 100kHz to 1MHz Adjustable clock frequency
• ±2.5% (over temperature) internal reference
• 10µA shutdown current (over temperature)
DESCRIPTION
The LM3478 is a versatile Low-Side N-Channel
MOSFET controller for switching regulators. It is
suitable for use in topologies requiring a low side
MOSFET, such as boost, flyback, or SEPIC.
Moreover, the LM3478 can be operated at extremely
high switching frequency in order to reduce the
overall solution size. The switching frequency of the
LM3478 can be adjusted to any value between
100kHz and 1MHz by using a single external resistor.
Current mode control provides superior bandwidth
and transient response, besides cycle-by-cycle
current limiting. Output current can be programmed
with a single external resistor.
The LM3478 has built in features such as thermal
shutdown, short-circuit protection, over voltage
protection, etc. Power saving shutdown mode
reduces the total supply current to 5µA and allows
power supply sequencing. Internal soft-start limits the
inrush current at start-up.
TYPICAL APPLICATION CIRCUIT
Figure 1. Typical High Efficiency Step-Up (Boost) Converter
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.
All trademarks are the property of their respective owners.
2
PRODUCT PREVIEW information concerns products in the
formative or design phase of development. Characteristic data and
other specifications are design goals. Texas Instruments reserves
the right to change or discontinue these products without notice.
Copyright © 2011–2013, Texas Instruments Incorporated