LM2652 1.5A, Dual High Performance Synchronous Buck Regulator
ADVANCE INFORMATION
January 2005
LM2652
1.5A, Dual High Performance Synchronous Buck
Regulator
General Description
The LM2652 is a monolithic dual synchronous buck regula-
tor designed for low output voltages. Special attention to
power sequencing, voltage accuracy and start-up character-
istics has been made to enable a simple solution to the
challenging requirements of FPGA & DSP power. Four inte-
grated FET power switches ensure high efficiency, minimal
external components and maximum ease-of-use. The IC can
accept an input of 2.7V to 5.5V and deliver 1.5A per channel.
The bias and power inputs can run from different rails to
balance system power. Output voltages are factory program-
mable from 0.8V to 3.3V in 50mV steps. The LM2652 is
available in two switching frequency options (650kHz and
1300kHz) and both options can be synchronized to an ex-
ternal clock of 300-1600kHz. The two switching channels run
180藲 out of phase to reduce input capacitor size and cost.
Output fault protection is provided by the use of cycle-by-
cycle current limit and frequency fold-back. Separate soft-
start, power good flags and output enables allow for power
sequencing flexibility.
Features
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Dual 1.5 Amp outputs
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Output voltage factory set in 50mV steps from 0.8V to
3.3V
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Input voltage from 2.7V to 5.5V
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2% reference accuracy
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4 internal 80m鈩?synchronous switches
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180藲 out of phase operation
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Independent enables (CMOS compatible)
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Separate Power Good flags
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650kHz or 1300kHz switching frequency
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PLL synchronization to an external clock
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Programmable soft-start
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Supports all-ceramic output capacitors
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TSSOP-28 Exposed Pad package
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Current limit and thermal shutdown protection
Applications
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Cable Modems
xDSL Modems
DSP, FPGA and microprocessor power
Local Regulation
Set-Top Box
Typical Application
20117201
漏 2005 National Semiconductor Corporation
DS201172
www.national.com
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