LM79L05,LM79L05AC,LM79L12,LM79L12AC,
LM79L15,LM79L15AC
LM79LXXAC Series 3-Terminal Negative Regulators
Literature Number: SNOSBR8J
LM79LXXAC Series
October 11, 2011
3-Terminal Negative Regulators
General Description
The LM79LXXAC series of 3-terminal negative voltage regu-
lators 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 perfor-
mance. The LM79LXXAC series, when combined with a min-
imum output capacitor of 0.1μF, exhibits an excellent
transient response, a maximum line regulation of 0.07% VO/
V, and a maximum load regulation of 0.01% VO/mA.
The LM79LXXAC series also includes, as self-protection cir-
cuitry: safe operating area circuitry for output transistor power
dissipation limiting, a temperature independent 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,
the 8-lead SOIC package, and the 6-Bump micro-SMD pack-
age.
For output voltages other than the pre-set -5V, -12V and -15V,
the LM137L series provides an adjustable output voltage
range from -1.2V to -47V.
Features
■Preset output voltage error is less than ±5% overload, line
and temperature
■Specified at an output current of 100mA
■Easily compensated with a small 0.1μF output
capacitor
■Internal short-circuit, thermal and safe operating area
protection
■Easily adjustable to higher output voltages
■Maximum line regulation less than 0.07% VOUT/V
■Maximum load regulation less than 0.01% VOUT/mA
■See AN-1112 for micro-SMD considerations
Typical Applications
Fixed Output Regulator
774801
*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.
Adjustable Output Regulator
774803
−V0 = −5V − (5V/R1 + IQ) • R2,
5V/R1 > 3 IQ
© 2011 National Semiconductor Corporation 7748 www.national.com
LM79LXXAC Series 3-Terminal Negative Regulators
Connection Diagrams
8-Lead SOIC Narrow (M)
774804
Pins labeled 'NC' on LM79LXXACM 8-Lead SOIC (pin 4 and pin 8) are Open, no internal connection.
Top View
3–Lead TO-92 (Z)
774802
Bottom View
6-Bump micro-SMD
774820
Top View (Bump Side Down)
Ordering Information
Package Part
Number
Package
Marking
Transport
Media
NSC
Drawing
8-Lead
SOIC
LM79L05ACM LM79L
05ACM
Rail of 95
M08A
LM79L05ACMX Reel of 2500
LM79L12ACM LM79L
12ACM
Rail of 95
LM79L12ACMX Reel of 2500
LM79L15ACM LM79L
15ACM
Rail of 95
LM79L15ACMX Reel of 2500
3-Pin
TO-92
LM79L05ACZ 320L
79L05 Box of 1800
Z03ALM79L12ACZ 320L
79L12 Box of 1800
LM79L15ACZ 320L
79L15 Obsolete
6-Bump
micro-SMD
LM79L05ACTL XVP
IB
Reel of 250 TLA06AMA
LM79L05ACTLX Reel of 3000
www.national.com 2
LM79LXXAC
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
VO = −5V, −12V, −15V −35V
Internal Power Dissipation (Note 2) Internally Limited
Operating Temperature Range 0°C to +70°C
Maximum Junction Temperature +125°C
Storage Temperature Range −55°C to +150°C
Lead Temperature
(Soldering, 10 sec.) 260°C
Electrical Characteristics (Note 3)
TA = 0°C to +70°C 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
VO
Output
Voltage
TJ = 25°C, IO = 100mA −5.2 −5 −4.8 −12.5 −12 −11.5 −15.6 −15 −14.4
V
1mA ≤ IO ≤ 100mA −5.25 −4.75 −12.6 −11.4 −15.75 −14.25
VMIN ≤ VIN ≤ VMAX (−20 ≤ VIN ≤ −7.5) (−27 ≤ VIN ≤ −14.8) (−30 ≤ VIN ≤ −18)
1mA ≤ IO ≤ 40mA −5.25 −4.75 −12.6 −11.4 −15.75 −14.25
VMIN ≤ VIN ≤ VMAX (−20 ≤ VIN ≤ −7) (−27 ≤ VIN ≤ −14.5) (−30 ≤ VIN ≤ −17.5)
ΔVO
Line
Regulation
TJ = 25°C, IO = 100mA 60 45 45 mV
VMIN ≤ VIN ≤ VMAX (−20 ≤ VIN ≤ −7.3) (−27 ≤ VIN ≤ −14.6) (−30 ≤ VIN ≤ −17.7) V
TJ = 25°C, IO = 40mA 60 45 45 mV
VMIN ≤ VIN ≤ VMAX (−20 ≤ VIN ≤ −7) (−27 ≤ VIN ≤ −14.5) (−30 ≤ VIN ≤ −17.5) V
ΔVO
Load
Regulation
TJ = 25°C 50 100 125 mV
1mA ≤ IO ≤ 100mA
ΔVO
Long Term
Stability IO = 100mA 20 48 60 mV/
khrs
IQ
Quiescent
Current IO = 100mA 2 6 2 6 2 6 mA
ΔIQ
Quiescen
Current
Change
1mA ≤ IO ≤ 100mA 0.3 0.3 0.3
1mA ≤ IO ≤ 40mA 0.1 0.1 0.1 mA
IO = 100mA 0.25 0.25 0.25 mA
VMIN ≤ VIN ≤ VMAX (−20 ≤ VIN ≤ −7.5) (−27 ≤ VIN ≤ −14.8) (−30 ≤ VIN ≤ −18) V
Vn
Output Noise
Voltage
TJ = 25°C, IO = 100mA
f = 10Hz − 10kHz
40 96 120 μV
Ripple
Rejection
TJ = 25°C, IO = 100mA
f = 120Hz 50 52 50 dB
Input Voltage
Required to TJ = 25°C, IO = 100mA −7.3 −14.6 −17.7 V
Maintain Line
Regulation IO = 40mA −7.0 −14.5 −17.5 V
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 TO-3 (Z) package is 60°C/W θJC, 232°C/W θJA at still air, and 88°C/W at 400 ft/min of air. The θJA of the LM78LXX in the 6-Bump
micro-SMD package is 114°C/W when mounted on a 4-Layer JEDEC test board (JESD 51-7). The θJA of the LM78LXX in the SOIC-8 (M) package is 180°C/W
in still air. The maximum junction temperature shall not exceed 125°C on electrical parameters.
Note 3: To ensure constant junction temperature, low duty cycle pulse testing is used.
3 www.national.com
LM79LXXAC
Typical Performance Characteristics
Maximum Average Power Dissipation (TO-92)
774811
Peak Output Current
774812
Short Circuit Output Current
774813
Dropout Voltage
774814
Ripple Rejection
774815
Output Voltage vs. Temperature
(Normalized to 1V @ 25°C)
774816
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LM79LXXAC
Quiescent Current
774817
Output Impedance
774818
Typical Applications
±15V, 100mA Dual Power Supply
774806
5 www.national.com
LM79LXXAC
Schematic Diagrams
−5V
774809
−12V and −15V
774810
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LM79LXXAC
Physical Dimensions inches (millimeters) unless otherwise noted
8-Lead, SOIC NARROW
NS Package Number M08A
TO-92, Molded, 3-Lead
NS Package Number Z03A
7 www.national.com
LM79LXXAC
NOTES: UNLESS OTHERWISE SPECIFIED
1. EPOXY COATING.
2. 63Sn/67Pb EUTECTIC BUMP.
3. RECOMMEND NON-SOLDER MASK DEFINED LANDING PAD.
4. PIN A1 ESTABLISHED BY LOWER LEFT CORNER WITH RESPECT TO TEXT ORIENTATION.
5. XXX IN DRAWING NUMBER REPRESENTS PACKAGE SIZE VARIATION WHERE X1 IS PACKAGE WIDTH, X2 IS PACKAGE LENGTH AND X3 IS PACK-
AGE HEIGHT.
6. REFERENCE JEEC REGISTRATION MO-211, VARIATION BC.
6-Bump micro SMD
NS Package Number TLA06AMA
X1 = 1006μm X2 = 1793μm X3 = 600μm
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LM79LXXAC
Notes
9 www.national.com
LM79LXXAC
Notes
LM79LXXAC Series 3-Terminal Negative Regulators
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