Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating ratings indicate conditions for which the device is func-
tional, but do not guarantee specific performance limits. Electrical Characteristics state DC and AC electrical specifications under particular test conditions which guar-
antee specific performance limits. This assumes that the device is within the Operating Ratings. Specifications are not guaranteed for parameters where no limit is
given, however, the typical value is a good indication of device performance.
Note 2:
Thermal resistance without a heat sink for junction to case temperature is 3˚C/W and for case to ambient temperature is 50˚C/W for the TO-220, 73˚C/W
for the TO-263. 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,
θ
JA
is 50˚C/W; with 1 square inch of copper area,
θ
JA
is 37˚C/W; and with 1.6 or more square inches of copper area,
θ
JA
is 32˚C/W.
Note 3:
All characteristics are measured with a capacitor across the input of 0.1 µF and a capacitor across the output of 10 µF. All characteristics except noise voltage
and ripple rejection ratio are measured using pulse techniques (t
W
≤10
ms, duty cycle≤5%). Output voltage changes due to changes in internal temperature must be
taken into account separately.
Note 4:
Guaranteed and 100% production tested.
Note 5:
Guaranteed (but not 100% production tested) over the operating temperature and input current ranges. These limits are not used to calculate outgoing qual-
ity levels.
Note 6:
To ensure constant junction temperature, low duty cycle pulse testing is used.
Typical Application
DS005539-5
*Required if regulator is located far from power supply filter.
*
*
C
OUT
must be at least 10 µF to maintain stability. May be increased without bound to maintain regulation during transients. Locate as close as possible to the
regulator. This capacitor must be rated over the same operating temperature range as the regulator. The equivalent series resistance (ESR) of this capacitor
should be less than 1Ω over the expected operating temperature range.
Typical Performance Characteristics
Output Impedance
Overvoltage Supply Current
Reverse Supply Current
DS005539-11
DS005539-12
DS005539-13
3
www.national.com
Typical Performance Characteristics
Output at Reverse
Supply
(Continued)
Output Voltage (Normalized
to 1V at T
j
= 25˚C)
Output at Overvoltage
DS005539-15
DS005539-14
DS005539-16
Dropout Voltage
Dropout Voltage
Low Voltage Behavior
DS005539-17
DS005539-18
DS005539-19
High Voltage Behavior
Line Transient Response
Load Transient Response
DS005539-20
DS005539-21
DS005539-22
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4
Typical Performance Characteristics
Peak Output Current
(Continued)
Quiescent Current
Quiescent Current
DS005539-23
DS005539-24
DS005539-25
Quiescent Current
Ripple Rejection
Ripple Rejection
DS005539-26
DS005539-27
DS005539-28
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 14V in-
put, 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 acceler-
ated 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
O
:
The percentage change in
output voltage for a thermal variation from room temperature
