LM340T-1.2 National Semiconductor, LM340T-1.2 Datasheet
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LM340T-1.2
Manufacturer Part Number
LM340T-1.2
Description
Manufacturer
National Semiconductor
Datasheet
1.LM340SX-5.0.pdf
(17 pages)
Specifications of LM340T-1.2
Case
TO220-3
Date_code
2002+
© 2006 National Semiconductor Corporation
LM340/LM78XX Series
3-Terminal Positive Regulators
General Description
The
3-terminal positive voltage regulators employ internal
current-limiting, thermal shutdown and safe-area compensa-
tion, making them essentially indestructible. If adequate heat
sinking is provided, they can deliver over 1.0A output cur-
rent. They are intended as fixed voltage regulators in a wide
range of applications including local (on-card) regulation for
elimination of noise and distribution problems associated
with single-point regulation. In addition to use as fixed volt-
age regulators, these devices can be used with external
components to obtain adjustable output voltages and cur-
rents.
Considerable effort was expended to make the entire series
of regulators easy to use and minimize the number of exter-
nal components. It is not necessary to bypass the output,
although this does improve transient response. Input by-
passing is needed only if the regulator is located far from the
filter capacitor of the power supply.
Typical Applications
*Required if the regulator is located far from the power supply filter.
**Although no output capacitor is needed for stability, it does help transient
response. (If needed, use 0.1 µF, ceramic disc).
∆I
Q
= 1.3 mA over line and load changes.
LM140/LM340A/LM340/LM78XXC
Fixed Output Regulator
Current Regulator
00778103
DS007781
00778101
monolithic
The 5V, 12V, and 15V regulator options are available in the
steel TO-3 power package. The LM340A/LM340/LM78XXC
series is available in the TO-220 plastic power package, and
the LM340-5.0 is available in the SOT-223 package, as well
as the LM340-5.0 and LM340-12 in the surface-mount TO-
263 package.
Features
n Complete specifications at 1A load
n Output voltage tolerances of
n Line regulation of 0.01% of V
n Load regulation of 0.3% of V
n Internal thermal overload protection
n Internal short-circuit current limit
n Output transistor safe area protection
n P
V
load regulation (L
OUT
over the temperature range (LM340A)
(LM340A)
Comparison between SOT-223 and D-Pak (TO-252)
+
= 5V + (5V/R1 + I
Product Enhancement tested
r
Adjustable Output Regulator
) ≈ [(R1 + R2)/R1] (L
Q
) R2 5V/R1
Packages
Scale 1:1
>
r
OUT
3 I
±
OUT
of LM340-5).
2% at T
Q
,
/A (LM340A)
/V of ∆V
00778102
j
00778138
= 25˚C and
IN
www.national.com
at 1A load
July 2006
±
4%