LM2925T National Semiconductor, LM2925T Datasheet - Page 5

• Manufacturer Part Number: LM2925T
• Description: IC REG LDO W/DELAY RESET TO220-5
• Manufacturer: National Semiconductor

Specifications of LM2925T

• Regulator Topology: Positive Fixed
• Voltage - Output: 5V
• Voltage - Input: Up to 26V
• Voltage - Dropout (typical): 0.82V @ 750mA
• Number Of Regulators: 1
• Current - Output: 500mA
• Current - Limit (min): 750mA
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Through Hole
• Package / Case: *
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: *LM2925T; LM2925

Typical Performance Characteristics
Quiescent Current
Peak Output Current
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.
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Quiescent Current
Maximum Power
Dissipation (TO-220)
(Continued)
5
Quiescent Current: The 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
put voltage for a thermal variation from room temperature to
either temperature extreme.
Application Hints
EXTERNAL CAPACITORS
The LM2925 output capacitor is required for stability. Without
it, the regulator output will oscillate, sometimes by many
volts. Though the 10 µF shown is the minimum recom-
mended value, actual size and type may vary depending
upon the application load and temperature range. Capacitor
effective series resistance (ESR) also effects the IC stability.
Since ESR varies from one brand to the next, some bench
work may be required to determine the minimum capacitor
value to use in production. Worst-case is usually determined
at the minimum junction and ambient temperature and maxi-
mum load expected.
Output capacitors can be increased in size to any desired
value above the minimum. One possible purpose of this
would be to maintain the output voltages during brief condi-
tions of negative input transients that might be characteristic
of a particular system.
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Load Transient Response
Output Capacitor ESR
O
: The percentage change in ou-
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