Simple and easy to design with (using off-the-shelf external components)
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100 mΩ DMOS output switch
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3.3V, 5V and 12V fixed output and adjustable (1.2V to 37V ) versions
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50μA standby current when switched OFF
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±2%maximum output tolerance over full line and load conditions
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Wide input voltage range: 8V to 40V
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External Sync clock capability (280KHz to 400KHz)
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260 KHz fixed frequency internal oscillator
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−40 to +125°C operating junction temperature range
Description
The LM2677 series of regulators are monolithic integrated circuits which provide all of the active functions for a step-down
(buck) switching regulator capable of driving up to 5A loads with excellent line and load regulation characteristics. High
efficiency (>90%) is obtained through the use of a low ON-resistance DMOS power switch. The series consists of fixed output
voltages of 3.3V, 5V and 12V and an adjustable output version.
The SIMPLE SWITCHER concept provides for a complete design using a minimum number of external components. The switching clock frequency can be
provided by an internal fixed frequency oscillator (260KHz) or from an externally provided clock in the range of 280KHz to
400Khz which allows the use of physically smaller sized components. A family of standard inductors for use with the LM2677
are available from several manufacturers to greatly simplify the design process. The external Sync clock provides direct and
precise control of the output ripple frequency for consistent filtering or frequency spectrum positioning.
The LM2677 series also has built in thermal shutdown, current limiting and an ON/OFF control input that can power down the
regulator to a low 50μA quiescent current standby condition. The output voltage is guaranteed to a ±2% tolerance.
Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR.
The Long Term Failure Rates were calculated
at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress
temperature of 150°C to an application temperature of 55°C.
For more information on Reliability Metrics, please click here.
LM2677
LM22677
