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
-5V, -12V, and -15V 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 0.1F, 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 -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 0.1F 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
00774801
*Required if the regulator is located far from the power supply filter. A 1F
aluminum electrolytic may be substituted.
**Required for stability. A 1F aluminum electrolytic may be substituted.
Adjustable Output Regulator
00774803
-V
0
= -5V - (5V/R1 + I
Q
)
R2,
5V/R1
>
3 I
Q
Connection Diagrams
6-Bump micro SMD
00774820
Bump Side Down
TO-92 Plastic Package (Z)
00774802
Bottom View
February 2005
LM320L/LM79LXXAC
Series
3-T
erminal
Negative
Regulators
2005 National Semiconductor Corporation
DS007748
www.national.com
Absolute Maximum Ratings
(Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Input Voltage
V
O
= -5V, -12V, -15V
-35V
Internal Power Dissipation (Note 2)
Internally Limited
Operating Temperature Range
0C to +70C
Maximum Junction Temperature
+125C
Storage Temperature Range
-55C to +150C
Lead Temperature
(Soldering, 10 sec.)
260C
Electrical Characteristics
(Note 3)
T
A
= 0C to +70C unless otherwise noted.
Output Voltage
-5V
-12V
-15V
Input Voltage (unless otherwise noted)
-10V
-17V
-20V
Units
Symbol
Parameter
Conditions
Min
Typ
Max
Min
Typ
Max
Min
Typ
Max
V
O
Output
Voltage
T
J
= 25C, I
O
= 100mA
-5.2
-5
-4.8
-12.5
-12
-11.5
-15.6
-15
-14.4
1mA
I
O
100mA
-5.25
-4.75
-12.6
-11.4
-15.75
-14.25
V
MIN
V
IN
V
MAX
(-20
V
IN
-7.5)
(-27
V
IN
-14.8)
(-30
V
IN
-18)
V
1mA
I
O
40mA
-5.25
-4.75
-12.6
-11.4
-15.75
-14.25
V
MIN
V
IN
V
MAX
(-20
V
IN
-7)
(-27
V
IN
-14.5)
(-30
V
IN
-17.5)
V
O
Line
Regulation
T
J
= 25C, I
O
= 100mA
60
45
45
mV
V
MIN
V
IN
V
MAX
(-20
V
IN
-7.3)
(-27
V
IN
-14.6)
(-30
V
IN
-17.7)
V
T
J
= 25C, I
O
= 40mA
60
45
45
mV
V
MIN
V
IN
V
MAX
(-20
V
IN
-7)
(-27
V
IN
-14.5)
(-30
V
IN
-17.5)
V
V
O
Load
Regulation
T
J
= 25C
50
100
125
mV
1mA
I
O
100mA
V
O
Long Term
Stability
I
O
= 100mA
20
48
60
mV/khrs
I
Q
Quiescent
Current
I
O
= 100mA
2
6
2
6
2
6
mA
I
Q
Quiescent
Current
1mA
I
O
100mA
0.3
0.3
0.3
Change
1mA
I
O
40mA
0.1
0.1
0.1
mA
I
O
= 100mA
0.25
0.25
0.25
mA
V
MIN
V
IN
V
MAX
(-20
V
IN
-7.5)
(-27
V
IN
-14.8)
(-30
V
IN
-18)
V
V
n
Output Noise
Voltage
T
J
= 25C, I
O
= 100mA
40
96
120
V
f = 10Hz - 10kHz
Ripple
Rejection
T
J
= 25C, I
O
= 100mA
50
52
50
dB
f = 120Hz
Input Voltage T
J
= 25C, I
O
= 100mA
-7.3
-14.6
-17.7
V
Required to
I
O
= 40mA
-7.0
-14.5
-17.5
V
Maintain Line
Regulation
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
functional, but do not guarantee specific performance limits.
Note 2: Thermal resistance of Z package is 60C/W
JC
, 232C/W
JA
at still air, and 88C/W at 400 ft/min of air. The M package
JA
is 180C/W in still air. The
maximum junction temperature shall not exceed 125C on electrical parameters.
Note 3: To ensure constant junction temperature, low duty cycle pulse testing is used.
LM320L/LM79LXXAC
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