SS6580/L
Step-Down DC/DC Controller with Shutdown
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FEATURES
Operating Voltage up to 15V.
Simple Voltage-Mode PWM Control.
Fast Transient Response.
2V and 1.3V
±
2% Feedback Voltage Reference
Options.
Adjustable Current Limit without External Sense
Resistors.
200 KHz Switching Oscillator.
Short-Circuit Protection with Low Short-Circuit
Output Current.
Low Shutdown Current
Built-in Soft Start.
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DESCRIPTION
The SS6580 is a high-power, high-efficiency
voltage-mode switching regulator controller for
motherboard V
I/O
power supply applications.
Designed to drive an N-channel MOSFET in a
standard buck topology, the SS6580 features
a
high
voltage
CMOS
output
driver
with
short-circuit protection in an 8-pin package.
An external 4-bit Digital-to-Analog Converter (DAC)
can be used along with the SS6580 to adjust
the output voltage from 2.0V to 3.5V in 0.1V
increments. Table 1 on the following page
specifies the corresponding output voltage for 16
combinations of DAC inputs as shown in the
typical application circuit.
The 200 KHz switching frequency allows the use
of small external components while maintaining
high conversion efficiency. The 11MHz bandwidth
and the 6V/µS slew rate of the error amplifier
ensure high converter bandwidth and fast transient
response.
The
SS6580
provides
both
adjustable
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APPLICATIONS
Power Supply for Motherboard V
GTL
(1.5V Output)
Power Supply for Motherboard V
I/O
.
High-Power 5V to 3.xV DC/DC Regulators.
Low-Voltage Distributed Power Supplies.
over-current and adjustable short-circuit protection
by sensing the output current across the on-
resistance of the external N-channel MOSFET,
rather than an external low value sense resistor.
The SS6580L provides a lower reference
voltage (1.30V) than the default SS6580
(2.00V) for lower V
OUT
requirements.
Rev.2.01 6/26/2003
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