LM117, LM317-N
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SNVS774L –MAY 2004–REVISED FEBRUARY 2011
LM117/LM317A/LM317-N 3-Terminal Adjustable Regulator
Check for Samples: LM117, LM317-N
Normally, no capacitors are needed unless the device
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FEATURES
is situated more than 6 inches from the input filter
capacitors in which case an input bypass is needed.
An optional output capacitor can be added to improve
transient response. The adjustment terminal can be
bypassed to achieve very high ripple rejection ratios
which are difficult to achieve with standard 3-terminal
regulators.
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Specified 1% Output Voltage Tolerance
(LM317A)
•
Specified Max. 0.01%/V Line Regulation
(LM317A)
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•
•
•
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Specified Max. 0.3% Load Regulation (LM117)
Specified 1.5A Output Current
Besides replacing fixed regulators, the LM117 is
useful in a wide variety of other applications. Since
the regulator is “floating” and sees only the input-to-
output differential voltage, supplies of several
hundred volts can be regulated as long as the
maximum input to output differential is not exceeded,
i.e., avoid short-circuiting the output.
Adjustable Output Down to 1.2V
Current Limit Constant With Temperature
P+ Product Enhancement Tested
80 dB Ripple Rejection
Output is Short-Circuit Protected
Also, it makes an especially simple adjustable
switching regulator, a programmable output regulator,
or by connecting a fixed resistor between the
adjustment pin and output, the LM117 can be used
DESCRIPTION
The LM117 series of adjustable 3-terminal positive
voltage regulators is capable of supplying in excess
of 1.5A over a 1.2V to 37V output range. They are
exceptionally easy to use and require only two
external resistors to set the output voltage. Further,
both line and load regulation are better than standard
fixed regulators. Also, the LM117 is packaged in
standard transistor packages which are easily
mounted and handled.
as
a precision current regulator. Supplies with
electronic shutdown can be achieved by clamping the
adjustment terminal to ground which programs the
output to 1.2V where most loads draw little current.
For applications requiring greater output current, see
LM150 series (3A) and LM138 series (5A) data
sheets. For the negative complement, see LM137
series data sheet.
In addition to higher performance than fixed
regulators, the LM117 series offers full overload
protection available only in IC's. Included on the chip
are current limit, thermal overload protection and safe
area protection. All overload protection circuitry
remains fully functional even if the adjustment
terminal is disconnected.
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PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
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