V

ing temperature range, −40˚C

≤ T

LM2990-12

LM2990-15

Units

(Limit)

Parameter

Conditions

Typ

Limit

Typ

Limit

(Note 4)

(Note 5)

(Note 4)

(Note 5)

Short Circuit Current

R

1.2

0.9

1.0

0.75

A (min)

Maximum Output Current

(Note 7)

1.8

1.4

1.8

1.4

A (min)

Ripple Rejection

V

52

42

52

42

dB (min)

ƒ

Output Noise Voltage

10 Hz–100 kHz, I

500

1500

600

1800

µV (max)

Long Term Stability

1000 Hours

2000

2000

ppm

Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is in-

tended to be functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics.

Note 2: Human body model, 100 pF discharged through a 1.5 k

Ω resistor.

160˚C. For the LM2990, the junction-to-ambient thermal resistance, is 53˚C/W, 73˚C/W for the TO-263, and the junction-to-case thermal resistance is 3˚C. If the

TO-263 package is used, the thermal resistance can be reduced by increasing the P.C. board copper area thermally connected to the package. Using 0.5 square

inches of copper area,

Note 5: Limits are guaranteed and 100% production tested.

Note 7: The short circuit current is less than the maximum output current with the −12V and −15V versions due to internal foldback current limiting. The −5V and

−5.2V versions, tested with a lower input voltage, does not reach the foldback current limit and therefore conducts a higher short circuit current level. If the LM2990

output is pulled above ground, the maximum allowed current sunk back into the LM2990 is 1.5A.

Definition of Terms

Dropout Voltage: The input-output voltage differential at

which the circuit ceases to regulate against further reduction

in input voltage. Measured when the output voltage has

dropped 100 mV from the nominal value obtained at (V

5V) input, dropout voltage is dependent upon load current

and junction temperature.

Input Voltage: The DC voltage applied to the input terminals

with respect to ground.

Input-Output Differential: The voltage difference between

the unregulated input voltage and the regulated output volt-

age for which the regulator will operate.

Line Regulation: The change in output voltage for a change

in the input voltage. The measurement is made under condi-

tions of low dissipation or by using pulse techniques such

that the average chip temperature is not significantly af-

fected.

Load Regulation: The change in output voltage for a

change in load current at constant chip temperature.

Long Term Stability: Output voltage stability under accelle-

rated life-test conditions after 1000 hours with maximum

rated voltage and junction temperature.

Output Noise Voltage: The rms AC voltage at the output,

with constant load and no input ripple, measured over a

specified frequency range.

Quiescent Current: That part of the positive input current

that does not contribute to the positive load current. The

regulator ground lead current.

Ripple Rejection: The ratio of the peak-to-peak input ripple

voltage to the peak-to-peak output ripple voltage.

Temperature Stability of V

output voltage for a thermal variation from room temperature

to either temperature extreme.

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