NSC LM2931Z-5.0, LM2931T-5.0, LM2931S-5.0, LM2931M-5.0, LM2931CT Datasheet

March 2000

LM2931

Series Low Dropout Regulators

General Description

The LM2931 positive voltage regulator features a very low quiescent current of 1mA or less when supplying 10mA loads. This unique characteristic and the extremely low input-output differential required for proper regulation (0.2V for output currents of 10mA) make the LM2931 the ideal regulator for standby power systems. Applications include memory standby circuits, CMOS and other low power processor power supplies as well as systems demanding as much as 100mA of output current.

Designed originally for automotive applications, the LM2931 and all regulated circuitry are protected from reverse battery installations or 2 battery jumps. During line transients, such as a load dump (60V) when the input voltage to the regulator can momentarily exceed the specified maximum operating voltage, the regulator will automatically shut down to protect both internal circuits and the load. The LM2931 cannot be harmed by temporary mirror-image insertion. Familiar regulator features such as short circuit and thermal overload protection are also provided.

The LM2931 family includes a fixed 5V output (±3.8% tolerance for A grade) or an adjustable output with ON/OFF pin.

Both versions are available in a TO-220 power package, TO-263 surface mount package, and an 8-lead surface mount package. The fixed output version is also available in the TO-92 plastic and 6-Bump micro SMD packages.

Features

nVery low quiescent current

nOutput current in excess of 100 mA

nInput-output differential less than 0.6V

nReverse battery protection

n60V load dump protection

n−50V reverse transient protection

nShort circuit protection

nInternal thermal overload protection

nMirror-image insertion protection

nAvailable in TO-220, TO-92, TO-263, SO-8 or 6-Bump micro SMD packages

nAvailable as adjustable with TTL compatible switch

nSee AN-1112 for micro SMD considerations

Connection Diagrams

FIXED VOLTAGE OUTPUT

TO-220 3-Lead Power Package

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Front View

8-Pin Surface Mount

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*NC = Not internally connected. Must be electrically isolated from the rest of the circuit for the micro SMD package.

Top View

TO-263 Surface-Mount Package

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Top View

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Side View

TO-92 Plastic Package

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Bottom View

Regulators Dropout Low LM2931Series

© 2000 National Semiconductor Corporation

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LM2931

Connection Diagrams (Continued)

6-Bump micro SMD

micro SMD Laser Mark

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Top View

(Bump Side Down)

ADJUSTABLE OUTPUT VOLTAGE

TO-220 5-Lead Power Package	TO-263
	5-Lead Surface-Mount Package

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Front View

Top View

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Side View

8-Pin Surface Mount

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Top View

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Connection Diagrams (Continued)

Ordering Information

Output	Package	Part Number	Package Marking	Transport Media	NSC
Number					Drawing
5V	3-Pin TO-220	LM2931T-5.0	LM2931T-5.0	Rails	T03B
		LM2931AT-5.0	LM2931AT-5.0	Rails
	3-Pin TO-263	LM2931S-5.0	LM2931S-5.0	Rails	TS3B
		LM2931AS-5.0	LM2931AS-5.0	Rails
	TO-92	LM2931Z-5.0	LM2931Z-5	1.8k Units per Box	Z03A
		LM2931AZ-5.0	LM2931AZ	1.8k Units per Box
	8-Pin	LM2931M-5.0	2931M-5.0	Rails	M08A
	SOIC
		LM2931AM-5.0	2931AM-5.0	Rails
	* 6-Bump	LM2931IBPX-5.0	-	Tape and Reel	BPA06HTA
	micro SMD
Adjustable,	5-Pin TO-220	LM2931CT	LM2931CT	Rails	T05A
3V to 24V
	5-Pin TO-263	LM2931CS	LM2931CS	Rails	TS5B
	8-Pin	LM2931CM	LM2931CM	Rails	M08A
	SOIC
3.3V	* 6-Bump	LM2931IBPX-3.3	-	Tape and Reel	BPA06HTA
	micro SMD

Note: The micro SMD package marking is a single digit manufacturing Date Code Only.

LM2931

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LM2931

Typical Applications

LM2931 Fixed Output

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*Required if regulator is located far from power supply filter.

**C2 must be at least 100 µF to maintain stability. May be increased without bound to maintain regulation during transients. Locate as close as possible to the regulator. This capacitor must be rated over the same operating temperature range as the regulator. The equivalent series resistance (ESR) of this capacitor is critical; see curve.

LM2931 Adjustable Output

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Note: Using 27k for R1 will automatically compensate for errors in VOUT due to the input bias current of the ADJ pin (approximately 1 µA).

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Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications.

Input Voltage
Operating Range	26V
Overvoltage Protection
LM2931A, LM2931C (Adjustable)	60V
LM2931	50V

Internal Power Dissipation
(Note 2) (Note 4)	Internally Limited
Operating Ambient Temperature
Range	−40ÊC to +85ÊC
Maximum Junction Temperature	125ÊC
Storage Temperature Range	−65ÊC to +150ÊC
Lead Temp. (Soldering, 10 seconds)	230ÊC
ESD Tolerance (Note 5)	2000V

Electrical Characteristics for Fixed 3.3V Version

VIN = 14V, IO = 10mA, TJ = 25ÊC, C2 = 100µF (unless otherwise specified) (Note 2)

Parameter	Conditions		LM2931-3.3		Units
		Typ		Limit
				(Note 3)
Output Voltage		3.3		3.465	VMAX
				3.135	VMIN
	4V £ VIN £ 26V, IO = 100 mA			3.630	VMAX
	−40ÊC £ TJ £ 125ÊC			2.970	VMIN
Line Regulation	4V £ VIN £ 26V	4		33	mVMAX
Load Regulation	5mA £ IO £ 100mA	10		50	mVMAX
Output Impedance	100mADC and 10mArms,	200			mW
	100Hz - 10kHz
Quiescent Current	IO £ 10mA, 4V £ VIN £ 26V	0.4		1.0	mAMAX
	−40ÊC £ TJ £ 125ÊC
	IO = 100mA, VIN = 14V, TJ = 25ÊC	15			mA
Output Noise Voltage	10Hz -100kHz, COUT = 100µF	330			µV rms
Long Term Stability		13			mV/1000 hr
Ripple Rejection	fO = 120Hz	80			dB
Dropout Voltage	IO = 10mA	0.05		0.2	VMAX
	IO = 100mA	0.30		0.6
Maximum Operational		33		26	VMIN
Input Voltage
Maximum Line Transient	RL = 500W, VO £ 5.5V,	70		50	VMIN
	T = 1ms, t £ 100ms
Reverse Polarity Input	VO ³ −0.3V, R L = 500W	−30		−15	V MIN
Voltage, DC
Reverse Polarity Input	T = 1ms, t £ 100ms, RL = 500W	−80		−50	V MIN
Voltage, Transient

Electrical Characteristics for Fixed 5V Version

VIN = 14V, IO = 10mA, TJ = 25ÊC, C2 = 100 µF (unless otherwise specified) (Note 2)

Parameter	Conditions	LM2931A-5.0		LM2931-5.0		Units
		Typ	Limit	Typ	Limit
			(Note 3)		(Note 3)
Output Voltage		5	5.19	5	5.25	VMAX
			4.81		4.75	VMIN
	6.0V £ VIN £ 26V, IO = 100mA		5.25		5.5	VMAX
	−40ÊC £ TJ £ 125ÊC		4.75		4.5	VMIN
Line Regulation	9V £ VIN £ 16V	2	10	2	10	mVMAX
	6V £ VIN £ 26V	4	30	4	30
Load Regulation	5 mA £ IO £ 100mA	14	50	14	50	mVMAX
Output Impedance	100mADC and 10mArms,	200		200		mW
	100Hz -10kHz

LM2931

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LM2931

Electrical Characteristics for Fixed 5V Version (Continued)

VIN = 14V, IO = 10mA, TJ = 25ÊC, C2 = 100 µF (unless otherwise specified) (Note 2)

Parameter	Conditions	LM2931A-5.0		LM2931-5.0			Units
		Typ	Limit	Typ	Limit
			(Note 3)		(Note 3)
Quiescent Current	IO £ 10mA, 6V £ VIN £ 26V	0.4	1.0	0.4	1.0	mAMAX
	−40ÊC £ TJ £ 125ÊC
	IO = 100mA, VIN = 14V, TJ = 25ÊC	15	30	15		mAMAX
			5			mAMIN
Output Noise Voltage	10Hz -100kHz, COUT = 100µF	500		500			µV rms
Long Term Stability		20		20		mV/1000
							hr
Ripple Rejection	fO = 120 Hz	80	55	80			dBMIN
Dropout Voltage	IO = 10mA	0.05	0.2	0.05	0.2		VMAX
	IO = 100mA	0.3	0.6	0.3	0.6
Maximum Operational Input		33	26	33	26		VMIN
Voltage
Maximum Line Transient	RL = 500W, VO £ 5.5V,	70	60	70	50		VMIN
	T = 1ms, t £ 100ms
Reverse Polarity Input	VO ³ −0.3V, R L = 500W	−30	−15	−30	−15	V	MIN
Voltage, DC
Reverse Polarity Input	T = 1ms, t £ 100ms, RL = 500W	−80	−50	−80	−50	V	MIN
Voltage, Transient

Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Electrical specifications do not apply when operating the device beyond its rated operating conditions.

Note 2: See circuit in Typical Applications. To ensure constant junction temperature, low duty cycle pulse testing is used.

Note 3: All limits are guaranteed for TJ = 25ÊC (standard type face) or over the full operating junction temperature range of −40ÊC to +125ÊC (bold type face).

Note 4: The maximum power dissipation is a function of maximum junction temperature TJmax, total thermal resistance θJA, and ambient temperature TA. The maxi-

mum allowable power dissipation at any ambient temperature is PD = (TJmax − T A)/θJA. If this dissipation is exceeded, the die temperature will rise above 150ÊC and the LM2931 will go into thermal shutdown. For the LM2931 in the TO-92 package, θJA is 195ÊC/W; in the SO-8 package, θJA is 160ÊC/W, and in the TO-220 package,

θJA is 50ÊC/W; in the TO-263 package, θJA is 73ÊC/W; and in the 6-Bump micro SMD package θJA is 290ÊC/W. If the TO-220 package is used with a heat sink, θJA is the sum of the package thermal resistance junction-to-case of 3ÊC/W and the thermal resistance added by the heat sink and thermal interface.

If the TO-263 package is used, the thermal resistance can be reduced by increasing the P.C. board copper area thermally connected to the package: Using 0.5 square inches of copper area, θJA is 50ÊC/W; with 1 square inch of copper area, θJA is 37ÊC/W; and with 1.6 or more square inches of copper area, θJA is 32ÊC/W.

Note 5: Human body model, 100 pF discharged through 1.5 kΩ.

Electrical Characteristics for Adjustable Version

VIN = 14V, VOUT = 3V, IO = 10 mA, TJ = 25ÊC, R1 = 27k, C2 = 100 µF (unless otherwise specified) (Note 2)

Parameter	Conditions	Typ	Limit	Units
				Limit
Reference Voltage		1.20	1.26	VMAX
			1.14	VMIN
	IO £ 100 mA, −40ÊC £ Tj £ 125ÊC, R1 = 27k		1.32	VMAX
	Measured from VOUT to Adjust Pin		1.08	VMIN
Output Voltage Range			24	VMAX
			3	VMIN
Line Regulation	VOUT + 0.6V £ VIN £ 26V	0.2	1.5	mV/VMAX
Load Regulation	5 mA £ IO £ 100 mA	0.3	1	%MAX
Output Impedance	100 mADC and 10 mArms, 100 Hz±10 kHz	40		mW/V
Quiescent Current	IO = 10 mA	0.4	1	mAMAX
	IO = 100 mA	15		mA
	During Shutdown RL = 500W	0.8	1	mAMAX
Output Noise Voltage	10 Hz±100 kHz	100		µVrms/V
Long Term Stability		0.4		%/1000 hr
Ripple Rejection	fO = 120 Hz	0.02		%/V

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