MC79L00, MC79L00A Series
ELECTRICAL CHARACTERISTICS (V = –33 V, I = 40 mA, C = 0.33 µF, C = 0.1 µF, 0°C < T < +125°C, unless otherwise noted).
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MC79L24C
MC79L24AC
Typ
Characteristics
Output Voltage (T = +25°C)
Symbol
Min
Typ
Max
Min
Max
Unit
V
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–22.1
–24
–25.9
–23
–24
–25
Vdc
mV
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Input Regulation
(T = +25°C)
Reg
line
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–27 Vdc ≥ V ≥ –38 Vdc
–
–
–
–
–
–
–
350
300
–
–
–
–
–
–
350
–
300
I
–27.5 Vdc ≥ V ≥ –38 Vdc
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–28 Vdc ≥ V ≥ –38 Vdc
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Load Regulation
Reg
mV
load
T = +25°C, 1.0 mA ≤ I ≤ 100 mA
–
–
–
–
200
100
–
–
–
–
200
100
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1.0 mA ≤ I ≤ 40 mA
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Output Voltage
V
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Vdc
–27 Vdc ≥ V ≥ –38 V, 1.0 mA ≤ I ≤ 40 mA
–
–
–
–
–
–22.8
–
–22.8
–
–
–
–25.2
–
–25.2
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–28 Vdc ≥ V ≥ –38 Vdc, 1.0 mA ≤ I ≤ 40 mA
–21.4
–21.4
–26.4
–26.4
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V = –33 Vdc, 1.0 mA ≤ I ≤ 70 mA
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Input Bias Current
I
mA
mA
IB
(T = +25°C)
–
–
–
–
6.5
6.0
–
–
–
–
6.5
6.0
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(T = +125°C)
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Input Bias Current Change
∆I
IB
–28 Vdc ≥ V ≥ –38 Vdc
–
–
–
–
1.5
0.2
–
–
–
–
1.5
0.1
I
1.0 mA ≤ I ≤ 40 mA
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Output Noise Voltage
(T = +25°C, 10 Hz ≤ f ≤ 100 kHz)
A
V
–
30
–
200
–
–
–
–
31
–
200
–
–
–
µV
dB
n
Ripple Rejection
RR
|V –V |
43
47
(–29 ≤ V ≤ –35 Vdc, f = 120 Hz, T = +25°C)
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Dropout Voltage
1.7
1.7
Vdc
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= 40 mA, T = +25°C
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APPLICATIONS INFORMATION
Design Considerations
high–frequency characteristics to insure stable operation
under all load conditions. A 0.33 µF or larger tantalum,
mylar, 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.
The MC79L00, A Series of fixed voltage regulators are
designed with Thermal Overload Protections that shuts
down the circuit when subjected to an excessive power
overload condition, Internal Short Circuit Protection that
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 length, or if the output load capacitance is large. An
input bypass capacitor should be selected to provide good
Input
MC79LXX
Output
+V
MC78LXX
+V
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in
C **
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0.1µF
C *
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0.33µF
0.1µF
0.1µF
0.33µF
A common ground is required between the input and the output
voltages. The input voltage must remain typically 2.0 V above
the output voltage even during the low point on the ripple voltage.
-V
MC79LXX
-V
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in
0.33µF
ă* C is required if regulator is located an appreciable
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ă* distance from the power supply filter
** C improves stability and transient response.
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Figure 1. Positive and Negative Regulator
Figure 2. Standard Application
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