
©2002 Fairchild Semiconductor Corporation
www.fairchildsemi.com
Rev. 1.0.2
Features
• Output Current up to 100mA
• No External Components
• Internal Thermal Over Load Protection
• Internal Short Circuit Current Limiting
• Output Voltage Offered in ±5% Tolerance
• Output Voltage of -5V, -8V, -12V, -15V, -18V, -24V
Description
These regulators employ internal current limiting and
thermal shutdown, making them essentially indestructible.
TO-92
1
8-SOP
SOT-89
1
1.GND 2.Input 3.Output
1. Output 2.3.6.7. Input 5. GND 4.8. NC
1
Internal Block Diagram
Q1
Q2
Q3
Q4
Q5
Q6
Q7
Q8
Q9
Q10
Q11
Q12
Q13Q14
Q15
Q16
Q17
R1
R2
R3
R4
R5
R6
R7
R15
R16
R17
R18
R26
R22
R24 R25
R29
R
R28
R23+R21
R27
D3
D2
D1
C1
GND
Output
Input
MC79LXXA/LM79LXXA
3-Terminal 0.1A Negative Voltage Regulator

MC79LXXA/LM79LXXA
2
Absolute Maximum Ratings
Electrical Characteristics(MC79L05A/LM79L05A)
(VI = -10V, IO = 40mA, CI = 0.33µF, CO = 0.1µF, 0°C ≤T
J
≤ +125°C, unless otherwise specified)
Note:
1. Load and line regulation are specified at constant junction temperature. Change in V
O
due to heating effects must be taken
into account separately. Pulse testing with low duty is used.
Parameter Symbol Value Unit
Input Voltage (for V
o
= -5V to -8V)
(for V
O
= -12V to -18V)
(for V
O
= -24V)
V
I
-30
-35
-40
V
Operating Temperature Range T
OPR
0 ~ +125 °C
Storage Temperature Range T
STG
-65 ~ +150 °C
Parameter Symbol Conditions Min. Typ. Max. Unit
Output Voltage V
O
TJ = +25°C -4.8 -5.0 -5.2 V
Line Regulation (Note1) ∆V
O
TJ =+25°C
-7.0V ≥ V
I
≥ -20V - 15 150 mV
-8V ≥ VI ≥ -20V - - 100 mV
Load Regulation (Note1) ∆V
O
TJ =+25°C
1.0mA ≤ I
O
≤ 100mA - 20 60 mV
1.0mA ≤ I
O
≤ 40mA - 10 30 mV
Output Voltage V
O
-7.0V≥ V
I
≥ -20V, 1.0mA ≤ IO ≤ 40mA -4.75 - -5.25 V
V
I
= -10V, 1.0mA ≤ I
O
≤ 70mA -4.75 - -5.25 V
Quiescent Current I
Q
TJ =+25°C-2.05.5
mA
T
J
= +125°C--6.0
Quiescent Current
Change
With Line ∆I
Q
-8V ≥ V
I
≥ -20V - - 1.5 mA
With Load ∆I
Q
1.0mA ≤ I
O
≤ 40mA - - 0.1 mA
Output Noise Voltage V
N
TA = +25°C,10Hz ≤ f ≤ 100kHz - 30 - µV
Ripple Rejection RR
f = 120Hz, -8V ≥ V
I
≥ -18V
T
J
= +25°C
41 60 - dB
Dropout Voltage V
D
TJ = +25°C-1.7-V

MC79LXXA/LM79LXXA
3
Electrical Characteristics (MC79L08A)
(Continued)
(VI = -14V, IO = 40mA, CI = 0.33µF, CO = 0.1µF, 0°C ≤T
J
≤ +125°C, unless otherwise specified)
Note:
1. Load an d lin e re gul ation ar e spec ifie d at con sta nt ju nct ion t empe rat ure. Chan ge i n V
O
due to heating effects must be taken
into account separately. Pulse testing with low duty is used.
Parameter Symbol Conditions Min. Typ. Max. Unit
Output Voltage V
O
TJ = +25°C -7.7 -8.0 -8.3 V
Line Regulation(Note1) ∆V
O
TJ = +25°C
-10.3V ≥ V
I
≥ -23V - - 175 mV
-12V ≥ VI ≥ -23V - - 125 mV
Load Regulation (Note1) ∆V
O
TJ = +25°C
1.0mA ≤ I
o
≤ 100mA - - 80 mV
1.0mA ≤ I
o
≤ 40mA - - 40 mV
Output Voltage V
O
-10.3V ≥ V
I
≥ -23V, 1.0mA ≤ Io ≤ 40mA -7.6 - -8.4
V
V
I
= -14V, 1.0mA ≤ I
o
≤ 70mA -7.6 - -8.4
Quiescent Current I
q
Tj = +25°C--6.0
mA
T
j
= +125°C--5.5
Quiescent Current
Change
With Line
∆I
Q
-11.7V ≥ V
I
≥ -23V - - 1.5 mA
With Load 1.0mA ≤ I
o
≤ 40mA - - 0.1 mA
Output Noise Voltage V
N
Tj = +25°C,10Hz ≤ f ≤ 100kHz - 50 - µV
Ripple Rejection RR
f = 120Hz, -11V ≥ V
I
≥ -21V
T
j
= +25°C
39 55 - dB
Dropout Voltage V
D
Tj = +25°C-1.7-V

MC79LXXA/LM79LXXA
4
Electrical Characteristics(MC79L12A)
(Continued)
(VI = -19V, IO = 40mA, CI = 0.33µF, CO = 0.1µF, 0°C ≤T
J
≤ +125°C, unless otherwise specified)
Note:
1. Load and line regulation are specified at constant junction temperature. Change in V
O
due to heating effects must be taken
into account separately. Pulse testing with low duty is used.
Parameter Symbol Conditions Min. Typ. Max. Unit
Output Voltage V
O
TJ = +25°C -11.5 -12.0 -12.5 V
Line Regulation (Note1) ∆V
O
TJ = +25°C
-14.5V ≥ V
I
≥ -27V - - 250 mV
-16V ≥ VI ≥ -27V - - 200 mV
Load Regulation (Note1) ∆V
O
TJ = +25°C
1.0mA ≤ I
O
≤ 100mA - - 100 mV
1.0mA ≤ I
O
≤ 40mA - - 50 mV
Output Voltage V
O
-14.5V > V
I
> -27V, 1.0mA ≤ IO ≤ 40mA -11.4 - -12.6 V
V
I
= -19V, 1.0mA ≤ I
O
≤ 70mA -11.4 - -12.6 V
Quiescent Current I
Q
TJ = +25°C--6.0
mA
T
J
= +125°C--6.5
Quiescent Current
Change
With Line ∆I
Q
-16V ≥ V
I
≥ -27V - - 1.5 mA
With Load ∆I
Q
1.0mA ≤ I
O
≤ 40mA - - 0.1 mA
Output Noise Voltage V
N
TA = +25°C,10Hz ≤ f ≤ 100kHz - 80 - µV
Ripple Rejection RR
f = 120Hz, -15V≥ V
I
≥ -25V
T
J
= +25°C
37 42 - dB
Dropout Voltage V
D
TJ = +25°C-1.7-V

MC79LXXA/LM79LXXA
5
Electrical Characteristics(MC79L15A)
(Continued)
(VI = -23V, IO = 40mA, CI = 0.33µF, CO = 0.1µF, 0°C ≤T
J
≤ +125°C, unless otherwise specified)
Note:
1. Load an d lin e re gul ation ar e spec ifie d at con sta nt ju nct ion t empe rat ure. Chan ge i n V
O
due to heating effects must be taken
into account separately. Pulse testing with low duty is used.
Parameter Symbol Conditions Min. Typ. Max. Unit
Output Voltage V
O
TJ = +25°C -14.4 -15.0 -15.6 V
Line Regulation (Note1) ∆V
O
TJ = +25°C
-17.5V ≥ V
I
≥ -30V - - 300 mV
-20V ≥ VI ≥ -30V - - 250 mV
Load Regulation (Note1) ∆V
O
TJ = +25°C
1.0mA ≤ I
O
≤ 100mA - - 150 mV
1.0mA ≤ I
O
≤ 40mA - - 75 mV
Output Voltage V
O
-17.5V ≥ V
I
≥ -30V, 1.0mA ≤ IO ≤ 40mA -14.25 - -15.75 V
V
I
= -23V, 1.0mA ≤ I
O
≤ 70mA -14.25 - -15.75 V
Quiescent Current I
Q
TJ = +25°C--6.0
mA
T
J
= +125°C--6.5
Quiescent Current
Change
With Line ∆I
Q
-20V ≥ V
I
≥ -30V - - 1.5 mA
With Load ∆I
Q
1.0mA ≤ I
O
≤ 40mA - - 0.1 mA
Output Noise Voltage V
N
TA = +25°C,10Hz ≤ f ≤ 100kHz - 90 - µV
Ripple Rejection RR
f = 120Hz, -18.5V ≥ V
I
≥ -28.5V
T
J
= +25°C
34 39 - dB
Dropout Voltage V
D
TJ = +25°C-1.7-V

MC79LXXA/LM79LXXA
6
Electrical Characteristics(MC79L18A)
(Continued)
(VI = -27V, IO = 40mA, CI = 0.33µF, CO = 0.1µF, 0°C ≤T
J
≤ +125°C, unless otherwise specified)
Note:
1. Load and line regulation are specified at constant junction temperature. Change in V
O
due to heating effects must be taken
into account separately. Pulse testing with low duty is used.
Parameter Symbol Conditions Min. Typ. Max. Unit
Output Voltage V
O
TJ = +25°C -17.3 -18.0 -18.7 V
Line Regulation (Note1) ∆V
O
TJ = +25°C
-20.7V ≥ V
I
≥ -33V - - 325 mV
-21V ≥ VI ≥ -33V - - 275 mV
Load Regulation (Note1) ∆V
O
TJ = +25°C
1.0mA ≤ I
O
≤ 100mA - - 170 mV
1.0mA ≤ I
O
≤ 40mA - - 85 mV
Output Voltage V
O
-20.7V > V
I
> -33V, 1.0mA ≤ IO ≤ 40mA -17.1 - -18.9 V
V
I
= -27V, 1.0mA ≤ I
O
≤ 70mA -17.1 - -18.9 V
Quiescent Current I
Q
TJ = +25°C--6.5
mA
T
J
= +125°C--6.0
Quiescent Current
Change
With Line ∆I
Q
-21V ≥ V
I
≥ -33V - - 1.5 mA
With Load ∆I
Q
1.0mA ≤ I
O
≤ 40mA - - 0.1 mA
Output Noise Voltage V
N
TA =+25°C,10Hz ≤ f ≤ 100kHz - 150 - µV
Ripple Rejection RR
f = 120Hz, -23V ≥ V
I
≥ -33V
T
J
= +25°C
33 48 - dB
Dropout Voltage V
D
TJ = +25°C-1.7-V

MC79LXXA/LM79LXXA
7
Electrical Characteristics(MC79L24A)
(Continued)
(VI = -33V, IO = 40mA, CI = 0.33µF, CO = 0.1µF, 0°C ≤T
J
≤ +125°C, unless otherwise specified)
Note:
1. Load an d lin e re gul ation ar e spec ifie d at con sta nt ju nct ion t empe rat ure. Chan ge i n V
O
due to heating effects must be taken
into account separately. Pulse testing with low duty is used.
Parameter Symbol Conditions Min. Typ. Max. Unit
Output Voltage V
O
TJ = +25°C -23 -24 -25 V
Line Regulation (Note1) ∆V
O
TJ = +25°C
-27V ≥ V
I
≥ -38V - - 350 mV
-28V ≥ VI ≥ -38V - - 300 mV
Load Regulation (Note1) ∆V
O
TJ = +25°C
1.0mA ≤ I
O
≤ 100mA - - 200 mV
1.0mA ≤ I
O
≤ 40mA - - 100 mV
Output Voltage V
O
-27V ≥ V
I
≥ -38V, 1.0mA ≤ IO ≤ 40mA -22.8 - -25.2 V
V
I
= -33V, 1.0mA ≤ I
O
≤ 70mA -22.8 - -25.2 V
Quiescent Current I
Q
TJ = +25°C--6.5
mA
T
J
= +125°C--6.0
Quiescent Current
Change
With Line ∆I
Q
-28V ≥ V
I
≥ -38V - - 1.5 mA
With Load ∆I
Q
1.0mA ≤ I
O
≤ 40mA - - 0.1 mA
Output Noise Voltage V
N
TA = +25°C,10Hz ≤ f ≤ 100kHz - 200 - µV
Ripple Rejection RR
f = 120Hz, -29V ≥ V
I
≥ -35V
T
J
= +25°C
31 47 - dB
Dropout Voltage V
D
TJ = +25°C-1.7-V

MC79LXXA/LM79LXXA
8
Typical Application
Design Considerations
The MC79LXXA/LM79LXXA Series of fixed voltage regulators are designed with Thermal Overload Pro tection that shuts
down the circuit when subjected to an excessive power overload condition. Internal Short Circuit Protection th at limits the
maximum current the circuit will pass. In many low current applications, compensation capacitors are not required. However,
it is recommended that the regulator input be bypassed with a capacitor if the regulator is connected to the power supply filter
with long wire lengths, or if the output load capacitance is large. An input bypass capacitor should be selected to provide good
high frequency characteristics to insure stable operation under all load conditions. A 0.33µF or larger tantalum , my lar, or other
capacitor having low internal impedance at high frequencies should be chosen. The bypass capacitor should be mounted with
the shortest possible leads directly across the regulator's input terminals. Normally good construction techniques should be
used to minimize ground loops and lead resistance drops since the regulator has no external sense lead. Bypassing the output is
also recommended.
A common ground is required between the Input and the output voltages. The input voltage must remain typically 2.0V above
the output voltage even during the low point on the input ripple voltage.
* C1 is required if regulator is located an appreciable distance from power supply filter.
* C
O
improves stability and transient response.
Figure 1. Posi tive And Negativ e Regulator
Figure 2. Typical Application
LM78LXXA
MC78LXXA
LM79LXXA
MC79LXXA
I
MC79LXXA
LM79LXXA

MC79LXXA/LM79LXXA
9
Mechanical Dimensions
Package
Dimensions in millimeters
0.46
±0.10
1.27TYP
(R2.29)
3.86MAX
[1.27
±0.20
]
1.27TYP
[1.27
±0.20
]
3.60
±0.20
14.47
±0.40
1.02
±0.10
(0.25)
4.58
±0.20
4.58
+0.25
–0.15
0.38
+0.10
–0.05
0.38
+0.10
–0.05
TO-92

MC79LXXA/LM79LXXA
10
Mechanical Dimensions
(Continued)
Package
Dimensions in millimeters
4.92 ±0.20
0.194 ±0.008
0.41 ±0.10
0.016 ±0.004
1.27
0.050
5.72
0.225
1.55 ±0.20
0.061 ±0.008
0.1~0.25
0.004~0.001
6.00 ±0.30
0.236 ±0.012
3.95 ±0.20
0.156 ±0.008
0.50 ±0.20
0.020 ±0.008
5.13
0.202
MAX
#1
#4
#5
0~8°
#8
0.56
0.022
()
1.80
0.071
MAX0.10
MAX0.004
MAX
MIN
+
0.10
-0.05
0.15
+
0.004
-0.002
0.006
8-SOP

MC79LXXA/LM79LXXA
11
Mechanical Dimensions
(Continued)
Package
Dimensions in millimeters
SOT-89
0.40
±0.10
2.50
±0.20
(0.50)
(0.40)
4.10
±0.20
0.40
+0.10
–0.05
0.50
±0.10
1.65
±0.10
4.50
±0.20
1.50
±0.20
C0.2
1.50 TYP 1.50 TYP
(1.10)

MC79LXXA/LM79LXXA
12/11/02 0.0m 001
Stock#DSxxxxxxxx
2002 Fairchild Semiconductor Corporation
LIFE SUPPORT POL I CY
FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES
OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR
CORPORATION. As used herein :
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the body,
or (b) support or sustain life, and (c) whose failure to
perform when properly used in accordance with
instructions for use provided in the labeling, can be
reasonably expected to result in a significant injury of the
user.
2. A critical component in any component of a life support
device or sys tem whose failure to perform can be
reasonably expec ted to cause the failur e of the life support
device or system, or to affect its safety or effec tiveness.
www.fairchildsemi.com
DISCLAIMER
FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY
PRODUCTS HEREI N TO IMPROVE RELIABILITY, FUNCTION OR DES IGN. FAIRCHILD DOES NOT ASSUME ANY
LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER
DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RI GHTS OF OTHERS.
Ordering Information
Product Number Package Operating Temperature
LM79L05ACZ TO-92 0 ~ +125°C
Product Number Package Operating Temperature
MC79L05ACP
TO-92
0 ~ +125°C
MC79L08ACP
MC79L12ACP
MC79L15ACP
MC79L18ACP
MC79L24ACP
MC79L05ACD
8-SOP
MC79L15ACD
MC79L05ACH SOT-89