LM3488_09 Datasheet, PDF (1/24 Pages) National Semiconductor (TI) – High Efficiency Low-Side N-Channel Controller for Switching Regulators

LM3488/LM3488Q
March 30, 2009
High Efficiency Low-Side N-Channel Controller for
Switching Regulators
General Description
The LM3488 is a versatile Low-Side N-FET high performance
controller for switching regulators. It is suitable for use in
topologies requiring low side FET, such as boost, flyback,
SEPIC, etc. Moreover, the LM3488 can be operated at ex-
tremely high switching frequency in order to reduce the overall
solution size. The switching frequency of LM3488 can be ad-
justed to any value between 100kHz and 1MHz by using a
single external resistor or by synchronizing it to an external
clock. Current mode control provides superior bandwidth and
transient response, besides cycle-by-cycle current limiting.
Output current can be programmed with a single external re-
sistor.
The LM3488 has built in features such as thermal shutdown,
short-circuit protection and over voltage protection. 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.
Key Specifications
■ ^{Wide supply voltage range of 2.97V to 40V}
■ ^{100kHz to 1MHz Adjustable and Synchronizable clock}
frequency
■ ^{±1.5% (over temperature) internal reference}
■ ^{5µA shutdown current (over temperature)}
Features
■ ^{LM3488Q is AEC-Q100 qualified and manufactured on an}
Automotive Grade Flow
■ ^{8-lead Mini-SO8 (MSOP-8) 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 softstart}
■ ^{Current Mode Operation}
■ ^{Undervoltage Lockout with hysteresis}
Applications
■ ^{Distributed Power Systems}
■ ^{Notebook, PDA, Digital Camera, and other Portable}
Applications
■ ^{Offline Power Supplies}
■ ^{Set-Top Boxes}
Typical Application Circuit
Typical SEPIC Converter
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