LM320L/LM79LXXAC Series 3-Terminal Negative Regulators
February 2005
LM320L/LM79LXXAC Series
3-Terminal Negative Regulators
General Description
The LM320L/LM79LXXAC dual marked series of 3-terminal
negative voltage regulators features fixed output voltages of
鈭?V, 鈭?2V, and 鈭?5V with output current capabilities in
excess of 100mA. These devices were designed using the
latest computer techniques for optimizing the packaged IC
thermal/electrical performance. The LM79LXXAC series,
even when combined with a minimum output compensation
capacitor of 0.1碌F, exhibits an excellent transient response,
a maximum line regulation of 0.07% V
O
/V, and a maximum
load regulation of 0.01% V
O
/mA.
The LM320L/LM79LXXAC series also includes, as self-
protection circuitry: safe operating area circuitry for output
transistor power dissipation limiting, a temperature indepen-
dent short circuit current limit for peak output current limiting,
and a thermal shutdown circuit to prevent excessive junction
temperature. Although designed primarily as fixed voltage
regulators, these devices may be combined with simple
external circuitry for boosted and/or adjustable voltages and
currents. The LM79LXXAC series is available in the 3-lead
TO-92 package, 8-lead SOIC package, and the 6-Bump
micro SMD package. The LM320L series is available in the
3-lead TO-92 package.
For output voltage other than 鈭?V, 鈭?2V and 鈭?5V, the
LM137L series provides an output voltage range from 1.2V
to 47V.
Features
n
Preset output voltage error is less than
鹵
5% overload,
line and temperature
n
Specified at an output current of 100mA
n
Easily compensated with a small 0.1碌F output
capacitor
n
Internal short-circuit, thermal and safe operating area
protection
n
Easily adjustable to higher output voltages
n
Maximum line regulation less than 0.07% V
OUT
/V
n
Maximum load regulation less than 0.01% V
OUT
/mA
n
See AN-1112 for micro SMD considerations
Typical Applications
Fixed Output Regulator
Adjustable Output Regulator
00774801
00774803
*Required if the regulator is located far from the power supply filter. A 1碌F
aluminum electrolytic may be substituted.
*
*
Required for stability. A 1碌F aluminum electrolytic may be substituted.
鈭扸
0
= 鈭?V 鈭?(5V/R1 + I
Q
)
鈥?/div>
R2,
5V/R1
>
3 I
Q
Connection Diagrams
6-Bump micro SMD
TO-92 Plastic Package (Z)
00774802
Bottom View
00774820
Bump Side Down
漏 2005 National Semiconductor Corporation
DS007748
www.national.com
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