LM2940/LM2940C
Electrical Characteristics
Output Voltage (V
O
)
Parameter
Long Term
Stability
Dropout Voltage
Short Circuit
Current
Maximum Line
Transient
R
O
= 100Ω
LM2940, T
≤
100 ms
I
O
= 1A
I
O
= 100 mA
Conditions
(Continued)
V
IN
= V
O
+ 5V, I
O
= 1A, C
O
= 22 µF, unless otherwise specified.
Boldface limits apply over the entire operating tempera-
ture range of the indicated device.
All other specifications apply for T
A
= T
J
= 25˚C.
12V
LM2940
Typ
Limit
48
0.5
110
1.9
0.8/1.0
150/200
1.6
0.7/1.0
150/200
1.6/1.3
LM2940/833
Limit
60
0.5
110
1.9
0.8/1.0
150/200
1.6
0.7/1.0
150/200
1.6/1.3
Typ
15V
LM2940
Limit
LM2940/833
Limit
mV/
1000 Hr
V
MAX
mV
MAX
A
MIN
Units
75
55
−30
−30
−75
−55
60/60
40/40
45
−15/−15
−15
−50/−50
−45/−45
−45/−45
−55
−45/−45
−45/−45
V
MIN
−15/−15
−30
−15
55
45
−15/−15
V
MIN
40/40
V
MIN
LM2940/883, T
≤
20 ms
LM2940C, T
≤
1 ms
Reverse Polarity
DC Input
Voltage
Reverse Polarity
Transient Input
Voltage
R
O
= 100Ω
LM2940, LM2940/883
LM2940C
R
O
= 100Ω
LM2940, T
≤
100 ms
LM2940/883, T
≤
20 ms
LM2940C, T
≤
1 ms
Thermal Performance
Thermal Resistance
Junction-to-Case
Thermal Resistance
Junction-to-Ambient
3-Lead TO-220
3-Lead TO-263
3-Lead TO-220
3-Lead TO-263
8-Lead LLP (Note 2)
4
4
60
80
35
˚C/W
˚C/W
˚C/W
˚C/W
˚C/W
Note 1:
Absolute Maximum Ratings are limits beyond which damage to the device may occur. Operating Conditions are conditions under which the device functions
but the specifications might not be guaranteed. For guaranteed specifications and test conditions see the Electrical Characteristics.
Note 2:
The maximum allowable power dissipation is a function of the maximum junction temperature, T
J
, the junction-to-ambient thermal resistance,
θ
JA
, and the
ambient temperature, T
A
. Exceeding the maximum allowable power dissipation will cause excessive die temperature, and the regulator will go into thermal shutdown.
The value of
θ
JA
(for devices in still air with no heatsink) is 60˚C/W for the TO-220 package, 80˚C/W for the TO-263 package, and 174˚C/W for the SOT-223 package.
The effective value of
θ
JA
can be reduced by using a heatsink (see Application Hints for specific information on heatsinking). The value of
θ
JA
for the LLP package
is specifically dependent on PCB trace area, trace material, and the number of layers and thermal vias. For improved thermal resistance and power dissipation for
the LLP package, refer to Application Note AN-1187. It is recommended that 6 vias be placed under the center pad to improve thermal performance.
Note 3:
ESD rating is based on the human body model, 100 pF discharged through 1.5 kΩ.
Note 4:
All limits are guaranteed at T
A
= T
J
= 25˚C only (standard typeface) or over the entire operating temperature range of the indicated device (boldface type).
All limits at T
A
= T
J
= 25˚C are 100% production tested. All limits at temperature extremes are guaranteed via correlation using standard Statistical Quality Control
methods.
Note 5:
All limits are guaranteed at T
A
= T
J
= 25˚C only (standard typeface) or over the entire operating temperature range of the indicated device (boldface type).
All limits are 100% production tested and are used to calculate Outgoing Quality Levels.
Note 6:
Output current will decrease with increasing temperature but will not drop below 1A at the maximum specified temperature.
7
www.national.com
NSC [ NATIONAL SEMICONDUCTOR ]
