LM3495 Datasheet, PDF (1/26 Pages) National Semiconductor (TI) – Emulated Peak Current Mode Buck Controller for Low Output Voltage

April 2006
LM3495
Emulated Peak Current Mode Buck Controller for Low
Output Voltage
General Description
The LM3495 is a PWM buck regulator which implements a
unique emulated peak current mode control. This control
method eliminates the switching noise which typically limits
current mode operation at extremely short duty cycles and
high operating frequency. The switching frequency is pro-
grammable between 200 kHz and 1.5 MHz, and can also be
synchronized to an external clock. The LM3495 is also very
fault tolerant with both switch node short, hiccup mode, and
adaptive duty cycle limit protection. A 0.6V 1% reference and
glitch free pre-biased start-up ensure the most demanding
digital loads operate reliably. Internal soft start and the ability
to track the output of another supply make the LM3495
versatile and efficient.
Features
n Input voltage from 2.9V to 18V
n Output voltage adjustable from 0.6V to 5.5V
n Feedback Accuracy: ±1%
n Low-side Sensing, Programmable Current Limit without
sense resistor
n Input Under Voltage Lockout
n Hiccup mode current limit protection eliminates thermal
runaway during fault conditions
n Internal soft start with tracking capability
n 200 kHz to 1.5 MHz Switching frequency,
Synchronizable
n On-chip gate drivers
n Soft output discharge during shutdown
n Startup into output pre-bias
n Operation from a single input rail
n Adaptive Duty Cycle Limit
n TSSOP-16 package
Applications
n Wide input voltage buck converters with low voltage,
high accuracy outputs
n Core logic regulators
n High-efficiency buck regulation
Typical Application
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