Fairchild Semiconductor MC78T05, MC78T12, MC78T15 Datasheet

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MC78TXX

3-Terminal 3A Positive Voltage Regulator

Features

•Output Current in Excess of 3.0A

•Output Transistor Safe Operating Area Compensation

•Power Dissipation :25W

•Internal Short Circuit Current Limiting

•Internal Thermal Overload Protection

•Output Voltage Offered in 4% Tolerance

•No External Components Required

•Output Voltage of 5,12 and 15V

Internal Block Diagram

Description

This family of fixed voltage regulators are monolithic integrated circuit capable of driving loads in excess of 3.0 A.

TO-220

GND

1

1.Input 2. GND 3. Output

INPUT		SERIES	OUTPUT
		PASS
1		ELEMENT	3
	CURRENT	SOA
	GENERATOR
		PROTECTION
STARTING	REFERENCE	ERROR
CIRCUIT	VOLTAGE	AMPLIFIER
		THERMAL
		PROTECTION
			GND
			2

Rev. 1.0.1

©2002 Fairchild Semiconductor Corporation

MC78TXX

Absolute Maximum Ratings

	Parameter	Symbol	Value	Unit
	Input Voltage (for VO = 5V to 12V)	VI	35	V
	(for VO = 15V)		40	V
	Power Dissipation	PD	Internally limited
	Thermal Resistance, Junction to Air (Note1, 2)	Rθ JA	65	° C/W
	Ta = +25° C
	Thermal Resistance, Junction to Case (Note1)	Rθ JC	2.5	° C/W
	Tc = +25° C
	Operating Junction Temperature Range	TJ	0 ~ +125	° C
	Storage Temperature Range	TSTG	-65 ~ +150	° C

Note:

1. Thermal resistance test board

Size: 76.2mm * 114.3mm * 1.6mm(1S0P) JEDEC standard: JESD51-3, JESD51-7

2. Assume no ambient airflow.

Electrical Characteristics(MC78T05)

(VI = 10V, IO = 3.0 A, 0° C ≤ TJ ≤ +125° C, Po ≤ PMAX (Note3), unless otherwise specified. )

	Parameter	Symbol				Conditions		Min.	Typ.	Max.	Unit
	Output Voltage	Vo	5mA	≤	Io ≤	3.0A , TJ = +25° C		4.8	5.0	5.2	V
			7.3V	≤	VI ≤	20V, 5mA ≤ Io ≤ 2.0A		4.75	5.0	5.25
			7.2V ≤		VI ≤	35V , Io=5mA, TJ =+25° C
	Line Regulation (Note4)	∆ VO	7.2V	≤	VI ≤	35V , Io=1.0A, TJ = +25° C		-	3.0	25	mV
			7.5V	≤	VI ≤	20V, Io =2.0A, TJ = +25° C
			8.0V ≤		VI ≤	12V, Io =3.0A, TJ = +25° C
	Load Regulation (Note4)	∆ VO	5mA ≤		Io ≤	3.0A , TJ = +25° C		-	10	30	mV
			5mA	≤	Io ≤	3.0A			15	80	mV
	Thermal Regulation	REGT	Pulse =10ms, P = 20W					-	0.002	0.03	%Vo/W
			TA = +25° C
	Quiescent Current	IQ	5mA ≤		Io ≤	3.0A , TJ = +25° C		-	3.5	5.0	mA
			5mA	≤	Io ≤	3.0A			4.0	6.0	mA
			7.2V ≤		VI ≤	35V, Io = 5mA
	Quiescent Current Change	∆ IQ	TJ = +25° C ;					-	0.1	0.8	mA
			7.5V	≤	VI ≤	20V, Io =2.0A ;
			5mA ≤		Io ≤	3.0A, TJ = +25° C
	Ripple Rejection	RR	f = 120Hz, 8V ≤ VI ≤				18V, Io = 2.0A	-	75	-	dB
			TJ = +25° C
	Dropout Voltage	VD	Io = 3A ,TJ = +25° C					-	2.2	2.5	V
	Output Noise Voltage	VN	TA = +25° C, 10Hz ≤				f ≤ 100kHz	-	10	-	µ V/Vo
	Peak Output Current	IPK	TA = +25° C					-	5.0	-	A
	Output Resistance	Ro	f = 1.0kHz					-	2.0	-	mΩ
	Short Circuit Current Limit	Isc	VI = 35V, TJ =+25° C					-	1.5	2.5	A
	Average Temperature	∆ VO/∆ T	Io = 5.0mA					-	0.2	-	mV/° C
	Coefficient of Output Voltage

Note:

3.Although power dissipation is internally limited, specifications apply only for PO ≤ Pmax, Pmax = 25W

4.Load and line regulation are specified at constant junction temperature. Change in Vo due heating effects must be taken into account separately. Pulse testing with low duty is used.

2

MC78TXX

Electrical Characteristics(MC78T12) (Continued)

(VI = 19V, IO = 3.0 A, 0° C ≤ TJ ≤ +125° C, Po ≤ PMAX (Note1), unless otherwise specified. )

Parameter

Symbol

Conditions

Min.

Typ.

Max.

Unit

Output Voltage

Vo

5mA ≤

Io ≤

3.0A , TJ =+25° C

11.5

12

12.5

V

14.5V

≤

VI ≤

27V, 5mA ≤ Io ≤ 2.0A

11.4

12

12.8

14.5V

≤

VI ≤

35V, Io=5mA, TJ =+25° C

Line Regulation (Note2)

∆ VO

14.5V

≤

VI ≤

35V, Io=1.0A, TJ =+25° C

-

6.0

45

mV

14.9V

≤

VI ≤

28V, Io =2.0A, TJ =+25°

C

16V ≤

VI ≤

22V, Io =3.0A, TJ =+25° C

Load Regulation (Note2)

∆ VO

5mA ≤

Io ≤

3.0A, TJ =+25° C

-

10

30

mV

5mA ≤

Io ≤

3.0A

15

80

mV

Thermal Regulation

REGT

Pulse =10ms, P = 20W

-

0.002

0.03

%Vo/W

TA = +25° C

Quiescent Current

IQ

5mA ≤

Io ≤

3.0A, TJ =+25° C

-

3.5

5.0

mA

5mA ≤

Io ≤

3.0A

4.0

6.0

mA

14.5V

≤

VI ≤

35V, Io = 5mA

Quiescent Current Change

∆ IQ

TJ =+25° C ;

-

0.1

0.8

mA

14.9V

≤

VI ≤

27V, Io =2.0A ;

5mA ≤

Io ≤

3.0A, TJ =+25° C

Ripple Rejection

RR

f = 120Hz, 15V ≤ VI ≤

25V, Io = 2.0A

-

67

-

dB

TJ =+25° C

Dropout Voltage

VD

Io = 3A,TJ =+25° C

-

2.2

2.5

V

Output Noise Voltage

VN

TA =+25° C, 10Hz ≤ f ≤

100kHz

-

10

-

µ V/Vo

Peak Output Current

IPK

TA =+25° C

-

5.0

-

A

Output Resistance

Ro

f = 1.0kHz

-

2.0

-

mΩ

Short Circuit Current Limit

Isc

VI = 35V, TJ =+25° C

-

1.5

2.5

A

Average Temperature

∆ VO/∆ T

Io = 5.0mA

-

0.5

-

mV/° C

Coefficient of Output Voltage

Note:

1.Although power dissipation is internally limited, specifications apply only for PO ≤ Pmax, Pmax = 25W

2.Load and line regulation are specified at constant junction temperature. Change in Vo due heating effects must be taken into account separately. Pulse testing with low duty is used. ( PMAX = 25W)

3