LM2990SX-12 Datasheet, PDF (1/20 Pages) Texas Instruments – LM2990 Negative Low Dropout Regulator

LM2990
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SNVS093D – JUNE 1999 – REVISED APRIL 2013
LM2990 Negative Low Dropout Regulator
Check for Samples: LM2990
FEATURES
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•2 5% Output Accuracy over Entire Operating
Range
• Output Current in Excess of 1A
• Dropout Voltage Typically 0.6V at 1A Load
• Low Quiescent Current
• Internal Short Circuit Current Limit
• Internal Thermal Shutdown with Hysteresis
• Functional Complement to the LM2940 Series
APPLICATIONS
• Post Switcher Regulator
• Local, On-Card, Regulation
• Battery Operated Equipment
DESCRIPTION
The LM2990 is a three-terminal, low dropout, 1
ampere negative voltage regulator available with fixed
output voltages of −5, −5.2, −12, and −15V.
The LM2990 uses new circuit design techniques to
provide low dropout and low quiescent current. The
dropout voltage at 1A load current is typically 0.6V
and an ensured worst-case maximum of 1V over the
entire operating temperature range. The quiescent
current is typically 1 mA with 1A load current and an
input-output voltage differential greater than 3V. A
unique circuit design of the internal bias supply limits
the quiescent current to only 9 mA (typical) when the
regulator is in the dropout mode (V_OUT − V_IN ≤ 3V).
Output voltage accuracy is ensured to ±5% over load,
and temperature extremes.
The LM2990 is short-circuit proof, and thermal
shutdown includes hysteresis to enhance the
reliability of the device when overloaded for an
extended period of time. The LM2990 is available in a
3-lead package and is rated for operation over the
automotive temperature range of −40°C to +125°C.
Typical Application
*Required if the regulator is located further than 6 inches from the power supply filter capacitors. A 1 μF solid
tantalum or a 10 μF aluminum electrolytic capacitor is recommended.
**Required for stability. Must be at least a 10 μF aluminum electrolytic or a 1 μF solid tantalum to maintain stability.
May be increased without bound to maintain regulation during transients. Locate the capacitor as close as possible to
the regulator. The equivalent series resistance (ESR) is critical, and should be less than 10Ω over the same operating
temperature range as the regulator.
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2
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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