Fairchild Semiconductor MC7924, MC7912, MC7912A, MC7910, MC7918 Datasheet

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MC79XX/MC79XXA/LM79XX

3-Terminal 1A Negative Voltage Regulator

Features

•Output Current in Excess of 1A

•Output Voltages of -5, -6, -8 , -9, -10, -12, -15, -18 and - 24V

•Internal Thermal Overload Protection

•Short Circuit Protection

•Output Transistor Safe Operating Area Compensation

Description

The MC79XX / MC79XXA/ LM79XX series of three terminal negative regulators are available in TO-220 package and with several fixed output voltages, making them useful in a wide range of applications. Each type employs internal current limiting, thermal shut down and safe operating area protection, making it essentially indestructible.

TO-220 Vin

1

1. GND 2. Input 3. Output

Internal Block Digram

GND
		R1
VOLTAGE		R2
REFERENCE
	+	Output
	-	Q1
		Q2
		PROTECTION
I1	I2	CIRCUITRY
		Rsc
		In
		Input

Rev. 1.0.1

©2002 Fairchild Semiconductor Corporation

MC79XX/MC79XXA/LM79XX

Absolute Maximum Ratings

	Parameter	Symbol	Value	Unit
	Input Voltage	VI	-35	V
	Thermal Resistance Junction-Case (Note1)	Rθ JC	5	° C/W
	Thermal Resistance Junction-Air (Note1, 2)	Rθ JA	65
	Operating Temperature Range	TOPR	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 (MC7905/LM7905)

(VI = -10V, IO = 500mA, 0° C ≤ TJ ≤	+125° C, CI =2.2 F, CO =1 F, unless otherwise specified.)
Parameter	Symbol	Conditions			Min.	Typ.	Max.	Unit
Output Voltage	VO	TJ = +25° C			-4.8	-5.0	-5.2	V
		IO = 5mA to 1A, PO ≤ 15W			-4.75	-5.0	-5.25
		VI = -7V to -20V
Line Regulation (Note3)	∆ VO	TJ = +25° C		VI = -7V to -25V	-	35	100	mV
				VI = -8V to -12V	-	8	50
		TJ = +25° C			-	10	100
	∆ VO	IO = 5mA to 1.5A
Load Regulation (Note3)								mV
		TJ =+25° C			-	3	50
		IO = 250mA to 750mA
Quiescent Current	IQ	TJ =+25° C			-	3	6	mA
Quiescent Current Change	∆ IQ	IO = 5mA to 1A			-	0.05	0.5	mA
		VI = -8V to -25V			-	0.1	0.8
Temperature Coefficient of VD	∆ Vo/∆ T	IO = 5mA			-	- 0.4	-	mV/° C
Output Noise Voltage	VN	f = 10Hz to 100kHz			-	40	-	V
		TA =+25° C
Ripple Rejection	RR	f = 120Hz			54	60	-	dB
		∆ VI = 10V
Dropout Voltage	VD	TJ = +25° C			-	2	-	V
		IO = 1A
Short Circuit Current	ISC	TJ =+25° C, VI = -35V			-	300	-	mA
Peak Current	IPK	TJ =+25° C			-	2.2	-	A

Note

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

2

MC79XX/MC79XXA/LM79XX

Electrical Characteristics (MC7906) (Continued)

(VI = -11V, IO = 500mA, 0° C ≤ TJ ≤	+125° C, CI =2.2 F, CO =1 F, unless otherwise specified.)
Parameter	Symbol	Conditions			Min.	Typ.	Max.	Unit
Output Voltage	VO	TJ = +25° C			-5.75	-6	-6.25	V
		IO = 5mA to 1A, PO ≤ 15W			-5.7	-6	-6.3
		VI = -9V to -21V
Line Regulation (Note1)	∆ VO	TJ = +25° C		VI = -8V to -25V	-	10	120	mV
				VI = -9V to -13V	-	5	60
		TJ = +25° C			-	10	120
	∆ VO	IO = 5mA to 1.5A
Load Regulation (Note1)								mV
		TJ =+25° C			-	3	60
		IO = 250mA to 750mA
Quiescent Current	IQ	TJ =+25° C			-	3	6	mA
Quiescent Current Change	∆ IQ	IO = 5mA to 1A			-	0.05	0.5	mA
		VI = -8V to -25V			-	0.1	1.3
Temperature Coefficient of VD	∆ Vo/∆ T	IO = 5mA			-	-0.5	-	mV/° C
Output Noise Voltage	VN	f = 10Hz to 100kHz			-	130	-	V
		TA =+25° C
Ripple Rejection	RR	f = 120Hz			54	60	-	dB
		∆ VI = 10V
Dropout Voltage	VD	TJ = +25° C			-	2	-	V
		IO = 1A
Short Circuit Current	ISC	TJ = +25° C, VI = -35V			-	300	-	mA
Peak Current	IPK	TJ = +25° C			-	2.2	-	A

Note

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

3

MC79XX/MC79XXA/LM79XX

Electrical Characteristics (MC7908) (Continued)

	(VI = -14V, IO = 500mA, 0° C ≤ TJ ≤	+125° C, CI =2.2 F, CO =1 F, unless otherwise specified.)
	Parameter	Symbol	Conditions		Min.	Typ.	Max.	Unit
	Output Voltage	VO	TJ = +25° C		-7.7	-8	-8.3	V
			IO = 5mA to 1A, PO ≤ 15W		-7.6	-8	-8.4
			VI = -10V to -23V
	Line Regulation (Note1)	∆ VO	TJ = +25° C	VI = -10.5V to -25V	-	10	160	mV
				VI = -11V to -17V	-	5	80
			TJ = +25° C		-	12	160
		∆ VO	IO = 5mA to 1.5A
	Load Regulation (Note1)							mV
			TJ =+25° C		-	4	80
			IO = 250mA to 750mA
	Quiescent Current	IQ	TJ =+25° C		-	3	6	mA
	Quiescent Current Change	∆ IQ	IO = 5mA to 1A		-	0.05	0.5	mA
			VI = -10.5V to -25V		-	0.1	1
	Temperature Coefficient of VD	∆ Vo/∆ T	IO = 5mA		-	-0.6	-	mV/° C
	Output Noise Voltage	VN	f = 10Hz to 100kHz		-	175	-	V
			TA =+25° C
	Ripple Rejection	RR	f = 120Hz		54	60	-	dB
			∆ VI = 10V
	Dropout Voltage	VD	TJ = +25° C		-	2	-	V
			IO = 1A
	Short Circuit Current	ISC	TJ = +25° C, VI = -35V		-	300	-	mA
	Peak Current	IPK	TJ = +25° C		-	2.2	-	A

Note

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

4

MC79XX/MC79XXA/LM79XX

Electrical Characteristics (MC7909) (Continued)

(VI = -15V, IO = 500mA, 0° C ≤ TJ ≤	+125° C, CI =2.2 F, CO =1 F, unless otherwise specified.)
Parameter	Symbol	Conditions			Min.		Typ.	Max.	Unit
Output Voltage	VO	TJ = +25° C			-8.7		-9.0	-9.3	V
		IO = 5mA to 1A, PO ≤ 15W			-8.6		-9.0	-9.4
		VI = -1.5V to -23V
Line Regulation (Note1)	∆ VO	TJ = +25° C		VI = -11.5V to -26V	-		10	180	mV
				VI = -12V to -18V	-		5	90
		TJ = +25° C			-		12	180
	∆ VO	IO = 5mA to 1.5A
Load Regulation (Note1)									mV
		TJ = +25° C			-		4	90
		IO = 250mA to 750mA
Quiescent Current	IQ	TJ = +25° C			-		3	6	mA
Quiescent Current Change	∆ IQ	IO = 5mA to 1A			-		0.05	0.5	mA
		VI = -11.5V to -26V			-		0.1	1
Temperature Coefficient of VD	∆ Vo/∆ T	IO = 5mA			-		-0.6	-	mV/° C
Output Noise Voltage	VN	f = 10Hz to 100kHz			-		175	-	V
		TA = +25° C
Ripple Rejection	RR	f = 120Hz			54		60	-	dB
		∆ VI = 10V
Dropout Voltage	VD	TJ = +25° C			-		2	-	V
		IO = 1A
Short Circuit Current	ISC	TJ = +25° C, VI = -35V			-		300	-	mA
Peak Current	IPK	TJ = +25° C			-		2.2	-	A

Note:

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

5

MC79XX/MC79XXA/LM79XX

Electrical Characteristics (MC7910) (Continued)

(VI = -17V, IO = 500mA, 0° C ≤ TJ ≤	+125° C, CI =2.2 F, CO =1 F, unless otherwise specified.)
Parameter	Symbol	Conditions				Min.		Typ.	Max.	Unit
Output Voltage	VO	TJ = +25° C				-9.6		-10	-10.4	V
		IO = 5mA to 1A, Pd ≤			15W	-9.5		-10	-10.5
		VI = -12V to -28
Line Regulation (Note1)	∆ VO	TJ = +25° C		VI = -12.5V to -28V		-		12	200	mV
				VI	= -14V to -20V	-		6	100
		TJ = +25° C				-		12	200
	∆ VO	IO = 5mA to 1.5A
Load Regulation (Note1)										mV
		TJ = +25° C				-		4	100
		IO = 250mA to 750mA
Quiescent Current	IQ	TJ = +25° C				-		3	6	mA
Quiescent Current Change	∆ IQ	IO = 5mA to 1A				-		0.05	0.5	mA
		VI = -12.5V to -28V				-		0.1	1
Temperature Coefficient of VO	∆ Vo/∆ T	IO = 5mA				-		-1	-	mV/° C
Output Noise Voltage	VN	10Hz ≤ f ≤ 100kHz				-		280	-	V
		TA =+25° C
Ripple Rejection	RR	f = 120Hz				54		60	-	dB
		∆ VI = 10V
Dropout Voltage	VD	TJ = +25° C				-		2	-	V
		IO = 1A
Short Circuit Current	ISC	TJ = +25° C, VI = -35V				-		300	-	mA
Peak Current	IPK	TJ = +25° C				-		2.2	-	A

Note:

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

6