LM2717_08 Datasheet, PDF (1/14 Pages) National Semiconductor (TI) – Dual Step-Down DC/DC Converter

March 4, 2008
LM2717
Dual Step-Down DC/DC Converter
General Description
The LM2717 is composed of two PWM DC/DC buck (step-
down) converters. The first converter is used to generate a
fixed output voltage of 3.3V. The second converter is used to
generate an adjustable output voltage. Both converters fea-
ture low R_DSON (0.16Ω) internal switches for maximum effi-
ciency. Operating frequency can be adjusted anywhere
between 300kHz and 600kHz allowing the use of small ex-
ternal components. External soft-start pins for each enables
the user to tailor the soft-start times to a specific application.
Each converter may also be shut down independently with its
own shutdown pin. The LM2717 is available in a low profile
24-lead TSSOP package ensuring a low profile overall solu-
tion.
Features
■ ^{Fixed 3.3V output buck converter with a 2.2A, 0.16Ω,}
internal switch
■ ^{Adjustable buck converter with a 3.2A, 0.16Ω, internal}
switch
■ ^{Operating input voltage range of 4V to 20V}
■ ^{Input undervoltage protection}
■ ^{300kHz to 600kHz pin adjustable operating frequency}
■ ^{Over temperature protection}
■ ^{Small 24-Lead TSSOP package}
Applications
■ ^{TFT-LCD Displays}
■ ^{Handheld Devices}
■ ^{Portable Applications}
■ ^{Laptop Computers}
Typical Application Circuit
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