LM320L/LM79LXXAC/LM13121 Series 3-Terminal Negative Regulators
January 2003
LM320L/LM79LXXAC/LM13121 Series
3-Terminal Negative Regulators
General Description
The LM320L/LM79LXXAC/LM13121 dual marked series of
3-terminal negative voltage regulators features fixed output
voltages of −5V, −12V, and −15V with output current capa-
bilities in excess of 100mA. These devices were designed
using the latest computer techniques for optimizing the pack-
aged IC thermal/electrical performance. The LM79LXXAC
series, even when combined with a minimum output com-
pensation capacitor of 0.1µF, 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/LM13121 series also includes, as
self-protection circuitry: safe operating area circuitry for out-
put transistor power dissipation limiting, a temperature inde-
pendent 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 volt-
ages 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 avail-
able in the 3-lead TO-92 package.
For output voltage other than −5V, −12V and −15V, the
LM137L series provides an output voltage range from 1.2V
to 47V.
Features
n
Preset output voltage error is less than
±
5% overload,
line and temperature
n
Specified at an output current of 100mA
n
Easily compensated with a small 0.1µF 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 1µF
aluminum electrolytic may be substituted.
*
*
Required for stability. A 1µF aluminum electrolytic may be substituted.
−V
0
= −5V − (5V/R1 + I
Q
)
•
R2,
5V/R1
>
3 I
Q
Connection Diagrams
6-Bump micro SMD
TO-92 Plastic Package (Z)
00774802
Bottom View
00774820
Bump Side Down
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