LM78L05ACZ - National Semiconductor

TL/H/10051

LM78L00 Series 3-Terminal Positive Voltage Regulators

June 1989

LM78L00 Series

3-Terminal Positive Voltage Regulators

General Description

The LM78L00 series of 3-terminal positive voltage regula-

tors employ internal current-limiting and thermal shutdown,

making them essentially indestructible. If adequate heat

sinking is provided, they can deliver up to 100 mA output

current. They are intended as fixed voltage regulators in a

wide range of applications including local (on-card) regula-

tion for elimination of noise and distribution problems asso-

ciated with single-point regulation. In addition, they can be

used with power pass elements to make high current volt-

age regulators. The LM78L00, used as a Zener diode/resis-

tor combination replacement, offers an effective output im-

pedance improvement of typically two orders of magnitude,

along with lower quiescent current and lower noise.

Features

YOutput current up to 100 mA

YNo external components

YInternal thermal overload protection

YInternal short circuit current-limiting

YAvailable in JEDEC TO-92

YOutput Voltages of 5.0V, 6.2V, 8.2V, 9.0V, 12V, 15V

YOutput voltage tolerances of g5% over the

temperature range

Connection Diagram

TL/H/10051–1

Top View

Order Number LM78L05ACZ, LM78L09ACZ,

LM78L12ACZ, LM78L15ACZ, LM78L62ACZ or LM78L82ACZ

See NS Package Number Z03A

C1995 National Semiconductor Corporation RRD-B30M115/Printed in U. S. A.

Absolute Maximum Ratings

If Military/Aerospace specified devices are required,

please contact the National Semiconductor Sales

Office/Distributors for availability and specifications.

Storage Temperature Range b65§Ctoa

150§C

Operation Junction Temperature Range

Commercial (LM78L00AC) 0§Ctoa

125§C

Lead Temperature

TO-92 Package/SO-8

(Soldering, 10 sec.) 265§C

Power Dissipation Internally Limited

Input Voltage

5.0V to 15V 35V

ESD Susceptibility to be determined

LM78L05AC

Electrical Characteristics

0§CsTAsa125§C, VIe10V, IOe40 mA, CIe0.33 mF, COe0.1 mF, unless otherwise specified (Note 1)

Symbol Parameter Conditions Min Typ Max Units

VOOutput Voltage TJe25§C 4.8 5.0 5.2 V

VR LINE Line Regulation TJe25§C 7.0V sVIs20V 55 150 mV

8.0V sVIs20V 45 100

VR LOAD Load Regulation TJe25§C 1.0 mA sIOs100V 11 60 mV

1.0 mA sIOs40 mA 5.0 30

VOOutput Voltage 7.0V sVIs20V 1.0 mA sIOs40 mA 4.75 5.25 V

(Note 2) 7.0V sVIsVMax 1.0 mA sIOs70 mA 4.75 5.25

IQQuiescent Current 2.0 5.5 mA

DIQQuiescent Current With Line 8.0V sVIs20V 1.5 mA

Change With Load 1.0 mA sIOs40 mA 0.1

NONoise TAe25§C, 10 Hz sfs100 kHz 40 mV

DVI/DVORipple Rejection f e120 Hz, 8.0V sVIs18V, TJe25§C4149 dB

DO Dropout Voltage TJe25§C 1.7 V

Ipk/IOS Peak Output/Output TJe25§C140 mA

Short Circuit Current

DVO/DT Average Temperature IOe5.0 mA b0.65 mV/§C

Coefficient of Output Voltage

Note 1: The maximum steady state usable output current and input voltage are very dependent on the heat sinking and/or lead length of the package. The data

above represent pulse test conditions with junction temperatures as indicated at the initiation of tests.

Note 2: Power Dissipation s0.75W.

LM78L62AC

Electrical Characteristics

0§CsTAsa125§C, VIe12V, IOe40 mA, CIe0.33 mF, COe0.1 mF, unless otherwise specified (Note 1)

Symbol Parameter Conditions Min Typ Max Units

VOOutput Voltage TJe25§C 5.95 6.2 6.45 V

VR LINE Line Regulation TJe25§C 8.5V sVIs20V 65 175 mV

9.0V sVIs20V 55 125

VR LOAD Load Regulation TJe25§C 1.0 mA sIOs100 mA 13 80 mV

1.0 mA sIOs40 mA 6.0 40

VOOutput Voltage 8.5V sVIs20V 1.0 mA sIOs40 mA 5.90 6.5 V

(Note 2) 8.5V sVIsVMax 1.0 mA sIOs70 mA 5.90 6.5

IQQuiescent Current 2.0 5.5 mA

DIQQuiescent Current With Line 8.0V sVIs20V 1.5 mA

Change With Load 1.0 mA sIOs40 mA 0.1

NONoise TAe25§C, 10 Hz sfs100 kHz 50 mV

DVI/DVORipple Rejection f e120 Hz, 10V sVIs20V, TJe25§C4046 dB

DO Dropout Voltage TJe25§C 1.7 V

Ipk/IOS Peak Output/Output TJe25§C140 mA

Short Circuit Current

DVO/DT Average Temperature IOe5.0 mA b0.75 mV/§C

Coefficient of Output Voltage

LM78L82AC

Electrical Characteristics

0§CsTAsa125§C, VIe14V, IOe40 mA, CIe0.33 mF, COe0.1 mF, unless otherwise specified (Note 1)

Symbol Parameter Conditions Min Typ Max Units

VOOutput Voltage TJe25§C 7.87 8.2 8.53 V

VR LINE Line Regulation TJe25§C 11V sVIs23V 80 175 mV

12V sVIs23V 70 125

VR LOAD Load Regulation TJe25§C 1.0 mA sIOs100 mA 15 80 mA

1.0 mA sIOs40 mA 8.0 40

VOOutput Voltage 11V sVIs23V 1.0 mA sIOs40 mA 7.8 8.5 V

(Note 2) 11V sVIsVMax 1.0 mA sIOs70 mA 7.8 8.6

IQQuiescent Current 2.1 5.5 mA

DIQQuiescent Current With Line 12V sVIs23V 1.5 mA

Change With Load 1.0 mA sIOs40 mA 0.1

NONoise TAe25§C, 10 Hz sfs100 kHz 60 mV

DVI/DVORipple Rejection f e120 Hz, 12V sVIs22V, TJe25§C3945 dB

DO Dropout Voltage TJe25§C 1.7 V

Ipk/IOS Peak Output/Output TJe25§C140 mA

Short Circuit Current

DVO/DT Average Temperature IOe5.0 mA b0.8 mV/§C

Coefficient of Output Voltage

Note 1: The maximum steady state usable output current and input voltage are very dependent on the heat sinking and/or lead length of the package. The data

above represent pulse test conditions with junction temperatures as indicated at the initiation of tests.

Note 2: Power Dissipation s0.75W.

LM78L09AC

Electrical Characteristics

0§CsTAsa125§C, VIe15V, IOe40 mA, CIe0.33 mF, COe0.1 mF, unless otherwise specified (Note 1)

Symbol Parameter Conditions Min Typ Max Units

VOOutput Voltage TJe25§C 8.64 9.0 9.36 V

VR LINE Line Regulation TJe25§C 11.5V sVIs24V 90 200 mV

13V sVIs24V 100 150

VR LOAD Load Regulation TJe25§C 1.0 mA sIOs100 mA 20 90 mV

1.0 mA sIOs40 mA 10 45

VOOutput Voltage 11.5V sVIs24V 1.0 mA sIOs40 mA 8.55 9.45 V

(Note 2) 11.5V sVIsVMax 1.0 mA sIOs70 mA 8.55 9.45

IQQuiescent Current 2.1 5.5 mA

DIQQuiescent Current With Line 11.5V sVIs24V 1.5 mA

Change With Load 1.0 mA sIOs40 mA 0.1

NONoise TAe25§C, 10 Hz sfs100 kHz 70 mV

DVI/DVORipple Rejection f e120 Hz, 15V sVIs25V, TJe25§C3844 dB

DO Dropout Voltage TJe25§C 1.7 V

Ipk/IOS Peak Output/Output TJe25§C140 mA

Short Circuit Current

DVO/DT Average Temperature IOe5.0 mA b0.9 mV/§C

Coefficient of Output Voltage

LM78L12AC

Electrical Characteristics

0§CsTAsa125§C, VIe19V, IOe40 mA, CIe0.33 mF, COe0.1 mF, unless otherwise specified (Note 1)

Symbol Parameter Conditions Min Typ Max Units

VOOutput Voltage TJe25§C 11.5 12 12.5 V

VR LINE Line Regulation TJe25§C 14.5V sVIs27V 120 250 mV

16V sVIs27V 100 200

VR LOAD Load Regulation TJe25§C 1.0 mA sIOs100 mA 20 100 mV

1.0 mA sIOs40 mA 10 50

VOOutput Voltage 14.5V sVIs27V 1.0 mA sIOs40 mA 11.4 12.6 V

(Note 2) 14.5V sVIsVMax 1.0 mA sIOs70 mA 11.4 12.6

IQQuiescent Current 2.1 5.5 mA

DIQQuiescent Current With Line 16V sVIs27V 1.5 mA

Change With Load 1.0 mA sIOs40 mA 0.1

NONoise TAe25§C, 10 Hz sfs100 kHz 80 mV

DVI/DVORipple Rejection f e120 Hz, 15V sVIs25V, TJe25§C3742 dB

DO Dropout Voltage TJe25§C 1.7 V

Ipk/IOS Peak Output/Output TJe25§C140 mA

Short Circuit Current

DVO/DT Average Temperature IOe5.0 mA b1.0 mV/§C

Coefficient of Output Voltage

Note 1: The maximum steady state usable output current and input voltage are very dependent on the heat sinking and/or lead length of the package. The data

above represent pulse test conditions with junction temperatures as indicated at the initiation of tests.

Note 2: Power Dissipation s0.75W.

LM78L15AC

Electrical Characteristics

0§CsTAsa125§C, VIe23V, IOe40 mA, CIe0.33 mF, COe0.1 mF, unless otherwise specified (Note 1)

Symbol Parameter Conditions Min Typ Max Units

VOOutput Voltage TJe25§C 14.4 15 15.6 V

VR LINE Line Regulation TJe25§C 17.5V sVIs30V 130 300 mV

20V sVIs30V 110 250

VR LOAD Load Regulation TJe25§C 1.0 mA sIOs100 mA 25 150 mV

1.0 mA sIOs40 mA 12 75

VOOutput Voltage 17.5V sVIs30V 1.0 mA sIOs40 mA 14.25 15.75 V

(Note 2) 17.5V sVIsVMax 1.0 mA sIOs70 mA 14.25 15.75

IQQuiescent Current 2.2 5.5 mA

DIQQuiescent Current With Line 20V sVIs30V 1.5 mA

Change With Load 1.0 mA sIOs40 mA 0.1

NONoise TAe25§C, 10 Hz sfs100 kHz 90 mV

DVI/DVORipple Rejection f e120 Hz, 18.5V sVIs28.5V, TJe25§C3439 dB

DO Dropout Voltage TJe25§C 1.7 V

Ipk/IOS Peak Output/Output TJe25§C140 mA

Short Circuit Current

DVO/DT Average Temperature IOe5.0 mA b1.3 mV/§C

Coefficient of Output Voltage

Note 1: The maximum steady state usable output current and input voltage are very dependent on the heat sinking and/or lead length of the package. The data

above represent pulse test conditions with junction temperatures as indicated at the initiation of tests.

Note 2: Power Dissipation s0.75W.

Equivalent Circuit

TL/H/10051–2

Typical Performance Characteristics

Ambient Temperature (TO-92)

Dissipation vs

Worst Case Power

Junction Temperature

Dropout Voltage vs

Dropout Characteristics

Input Voltage

Quiescent Current vs

Temperature

Quiescent Current vs

Frequency

Ripple Rejection vs

Line Transient Response Load Transient Response

TL/H/10051–3

Note: Other LM78L00 Series devices have similar curves.

Design Considerations

The LM78L series regulators have thermal overload protec-

tion from excessive power, internal short-circuit protection

which limits each circuit’s maximum current, and output

transistor safe-area protection for reducing the output cur-

rent as the voltage across each pass transistor is increased.

Although the internal power dissipation is limited, the junc-

tion temperature must be kept below the maximum speci-

fied temperature (125§C) in order to meet data sheet specifi-

cations. To calculate the maximum junction temperature or

heat sink required, the following thermal resistance values

should be used:

Package Typ Max Typ Max

iJC iJC iJA iJA

TO-92 160 160

Thermal Considerations

The TO-92 molded package is capable of unusually high

power dissipation due to the lead frame design. However, its

thermal capabilities are generally overlooked because of a

lack of understanding of the thermal paths from the semi-

conductor junction to ambient temperature. While thermal

resistance is normally specified for the device mounted

1 cm above an infinite heat sink, very little has been men-

tioned of the options available to improve on the conserva-

tively rated thermal capability.

An explanation of the thermal paths of the TO-92 will allow

the designer to determine the thermal stress he is applying

in any given application.

The TO-92 Package

The TO-92 package thermal paths are complex. In addition

to the path through the molding compound to ambient tem-

perature, there is another path through the leads, in parallel

with the case path, to ambient temperature, as shown in

Figure 1

The total thermal resistance in this model is then:

iJA e(iJC aiCA)(i

JL aiLA)

iJC aiCA aiJL aiLA

(1)

Where:

iJCethermal resistance of the case between the regu-

lator die and a point on the case directly above

the die location.

iCAethermal resistance between the case and air at

ambient temperature.

iJLethermal resistance from regulator die through the

input lead to a point (/16 inch below the regulator

case.

iLAetotal thermal resistance of the input/output

ground leads to ambient temperature.

iJAejunction to ambient thermal resistance.

TL/H/10051–4

FIGURE 1. TO-92 Thermal Equivalent Circuit

Methods of Heat Sinking

With two external thermal resistances in each leg of a paral-

lel network available to the circuit designer as variables, he

can choose the method of heat sinking most applicable to

his particular situation. To demonstrate, consider the effect

of placing a small 72 §C/W flag type heat sink, such as the

Staver F1-7D-2, on the LM78L00 molded case. The heat

sink effectively replaces the iCA

(Figure 2)

and the new

thermal resistance, iÊJA, equals 145 §C/W (assuming, 0.125

inch lead length).

The net change of 15 §C/W increases the allowable power

dissipation to 0.86W with a minimal inserted cost. A still

further decrease in iJA could be achieved by using a heat

sink rated at 46 §C/W, such as the Staver FS-7A. Also, if the

case sinking does not provide an adequate reduction in total

iJA, the other external thermal resistance, iLA, may be re-

duced by shortening the lead length from package base to

mounting medium. However, one point must be kept in

mind. The lead thermal path includes a thermal resistance,

iSA, from the leads at the mounting point to ambient, that is,

the mounting medium. iLA is then equal to iLS aiSA. The

new model is shown in

Figure 2

In the case of a socket, iSA could be as high as 270 §C/W,

thus causing a net increase in iJA and a consequent de-

crease in the maximum dissipation capability. Shortening

the lead length may return the net iJA to the original value,

but lead sinking would not be accomplished.

In those cases where the regulator is inserted into a copper

clad printed circuit board, it is advantageous to have a maxi-

mum area of copper at the entry points of the leads. While it

would be desirable to rigorously define the effect of PC

board copper, the real world variables are too great to allow

anything more than a few general observations.

Methods of Heat Sinking (Continued)

The best analogy for PC board copper is to compare it with

parallel resistors. Beyond some point, additional resistors

are not significantly effective; beyond some point, additional

copper area is not effective.

TL/H/10051–5

FIGURE 2. TO-92 Thermal Equivalent Circuit

(Lead at other than Ambient Temperature)

High Dissipation Applications

TL/H/10051–6

TL/H/10051–7

Where it is necessary to operate a LM78L00 regulator with a

large input/output differential voltage, the addition of series

resistor R1 will extend the output current range of the de-

vice by sharing the total power dissipation between R1 and

the regulator.

R1 eVI Min bVOb2.0V

IL Max aIQ

(2)

where:

IQis the regulator quiescent current.

Regulator power dissipation at maximum input voltage and

maximum load current is now

PD Max e(V1bVO)I

L Max aV1IQ(3)

where:

V1eVI Max b(IL Max aIQ)R1

The presence of R1 will affect load regulation according to

the equation:

Load regulation (at constant VI) (4)

eload regulation (at constant V1)

aline regulation (mV per V)

c(RI) c(DIL).

As an example, consider a 15V regulator with a supply volt-

age of 30 g5.0V, required to supply a maximum load cur-

rent of 30 mA. IQis 4.3 mA, and minimum load current is to

be 10 mA.

R1 e25 b15 b2

30 a4.3 e8

34.3

j240X(5)

V1e35 b(30 a4.3) 0.24 e35 b8.2 e26.8V

PD Max e(26.8 b15) 30 a26.8 (4.3)

e354 a115

e470 mW, which permit operation up to

70§C in most applications.

Line regulation of this circuit is typically 110 mV for an input

range of 25V– 35V at a constant load current; i.e. 11 mV/V.

Load regulation econstant V1load regulation (6)

(typically 10 mV, 10 mA– 30 mA IL)

a(11 mV/V) c0.24 c20 mA

(typically 53 mV)

e63 mV for a load current change of

20 mA at a constant VIof 30V.

Typical Applications

TL/H/10051–8

Note 1: To specify an output voltage, substitute voltage value for ‘‘00’’.

Note 2: Bypass capacitors are recommended for optimum stability and tran-

sient response and should be located as close as possible to the regulator.

LM78L00 Series 3-Terminal Positive Voltage Regulators

Physical Dimensions inches (millimeters)

Order Number LM78L05ACZ, LM78L09ACZ,

LM78L12ACZ, LM78L15ACZ, LM78L62ACZ or LM78L82ACZ

NS Package Number Z03A

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