LM3475 Datasheet, PDF (1/14 Pages) National Semiconductor (TI) – Hysteretic PFET Buck Controller

October 2004
LM3475
Hysteretic PFET Buck Controller
General Description
The LM3475 is a hysteretic P-FET buck controller designed
to support a wide range of high efficiency applications in a
very small SOT23-5 package. The hysteretic control scheme
has several advantages, including simple system design
with no external compensation, stable operation with a wide
range of components, and extremely fast transient re-
sponse. Hysteretic control also provides high efficiency op-
eration, even at light loads. The PFET architecture allows for
low component count as well as 100% duty cycle and ultra-
low dropout operation.
Features
n Easy to use control methodology
n 0.8V to V_IN adjustable output range
n High Efficiency (90% typical)
n ±0.9% (±1.5% over temp) feedback voltage
n 100% duty cycle capable
n Maximum operating frequency up to 2MHz
n Internal Soft-Start
n Enable pin
n SOT23-5 package
Applications
n TFT Monitor
n Auto PC
n Vehicle Security
n Navigation Systems
n Notebook Standby Supply
n Battery Powered Portable Applications
n Distributed Power Systems
Typical Application Circuit
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