NSC LM431CIZ, LM431CIMX, LM431CIM3X, LM431CIM3, LM431BIM3 Datasheet

December 1999

LM431

Adjustable Precision Zener Shunt Regulator

General Description

The LM431 is a 3-terminal adjustable shunt regulator with guaranteed temperature stability over the entire temperature range of operation. It is now available in a chip sized package (4-Bump micro SMD) using National's micro SMD package technology. The output voltage may be set at any level greater than 2.5V (VREF) up to 36V merely by selecting two external resistors that act as a voltage divided network. Due to the sharp turn-on characteristics this device is an excellent replacement for many zener diode applications.

Features

nAverage temperature coefficient 50 ppm/ÊC

nTemperature compensated for operation over the full temperature range

nProgrammable output voltage

nFast turn-on response

nLow output noise

nLM431 in micro SMD package

Connection Diagrams

TO-92: Plastic Package

SOT-23: 3-Lead Small Outline

	DS010055-28
DS010055-1	Top View
Top View
	4-Bump micro SMD
SO-8: 8-Pin Surface Mount

	DS010055-54
DS010055-2	Top View
Top view	(bump side down)

Regulator Shunt Zener Precision Adjustable LM431

© 1999 National Semiconductor Corporation

DS010055

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LM431

Ordering Information

Package	Typical Accuracy Order Number/Package Marking			Temperature	Transport Media	NSC
				Range		Drawing
	0.5%	1%	2%
TO-92	LM431CCZ/	LM431BCZ/	LM431ACZ/	0ÊC to +70ÊC
	LM431CCZ	LM431BCZ	LM431ACZ
					Rails	Z03A
	LM431CIZ/	LM431BIZ/	LM431AIZ/	−40ÊC to +85ÊC
	LM431CIZ	LM431BIZ	LM431AIZ
SO-8	LM431CCM/	LM431BCM/	LM431ACM/	0ÊC to +70ÊC
	431CCM	431BCM	LM431ACM
					Rails and Tape &Reel	M08A
	LM431CIM/	LM431BIM/	LM431AIM/	−40ÊC to +85ÊC
	431CIM	431BIM	LM431AIM
SOT-23	LM431CCM3/	LM431BCM3/	LM431ACM3/	0ÊC to +70ÊC
	N1B	N1D	N1F
					Rails and Tape &Reel	MA03B
	LM431CIM3	LM431BIM3	LM431AIM3	−40ÊC to +85ÊC
	N1A	N1C	N1E
micro SMD	±	±	LM431AIBP	−40ÊC to +85ÊC	250 Units Tape and Reel	BPA04AFA
			LM431AIBPX(Note 1)		3k Units Tape and Reel

Note 1: The micro SMD package marking is a 2 digit manufacturing Date Code only

micro SMD Top View Marking Example

DS010055-56

The LM431 micro SMD Package will be marked with a two digit date manufacturing code. The underline indicates the bottom of the marking. Pin one will be placed at the bottom left hand corner, and the rest of the pin numbers will follow counter-clockwise.

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Symbol and Functional Diagrams

DS010055-99

DS010055-55

DC Test Circuits

DS010055-4								DS010055-5
FIGURE 1. Test Circuit for VZ	=	VREF	Note: V	Z	= V	REF	(1 + R1/R2) + I	· R1
							REF

FIGURE 2. Test Circuit for VZ > VREF

DS010055-6

FIGURE 3. Test Circuit for Off-State Current

LM431

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LM431

Absolute Maximum Ratings (Note 2)

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

Storage Temperature Range	−65ÊC to +150ÊC
Operating Temperature Range
Industrial (LM431xI)	−40ÊC to +85ÊC
Commercial (LM431xC)	0ÊC to +70ÊC
Soldering Information
Infrared or Convection (20 sec.)	235ÊC
Wave Soldering (10 sec.)	260ÊC (lead temp.)
Cathode Voltage	37V
Continuous Cathode Current	−10 mA to +150 mA

Reference Voltage	−0.5V
Reference Input Current	10 mA
Internal Power Dissipation (Notes 3, 4)
TO-92 Package	0.78W
SO-8 Package	0.81W
SOT-23 Package	0.28W
micro SMD Package	0.30W

Operating Conditions

	Min	Max
Cathode Voltage	VREF	37V
Cathode Current	1.0 mA	100 mA

LM431

Electrical Characteristics

TA = 25ÊC unless otherwise specified

Symbol	Parameter	Conditions		Min	Typ	Max	Units
VREF	Reference Voltage	VZ = VREF, II = 10 mA		2.440	2.495	2.550	V
		LM431A (Figure 1 )
		VZ = VREF, II = 10 mA		2.470	2.495	2.520	V
		LM431B (Figure 1 )
		VZ = VREF, II = 10 mA		2.485	2.500	2.510	V
		LM431C (Figure 1 )
VDEV	Deviation of Reference Input Voltage Over	VZ = VREF, II = 10 mA,			8.0	17	mV
	Temperature (Note 5)	TA = Full Range (Figure 1 )
	Ratio of the Change in Reference Voltage	IZ = 10 mA	VZ from VREF to 10V		−1.4	−2.7	mV/V
	to the Change in Cathode Voltage
		(Figure 2 )	VZ from 10V to 36V		−1.0	−2.0
IREF	Reference Input Current	R1 = 10 kΩ, R2 = ∞,			2.0	4.0	µA
		II = 10 mA (Figure 2 )
IREF	Deviation of Reference Input Current over	R1 = 10 kΩ, R2 = ∞,
	Temperature	II = 10 mA,			0.4	1.2	µA
		TA = Full Range (Figure 2 )
IZ(MIN)	Minimum Cathode Current for Regulation	VZ = VREF (Figure 1 )			0.4	1.0	mA
IZ(OFF)	Off-State Current	VZ = 36V, VREF = 0V (Figure 3 )			0.3	1.0	µA
rZ	Dynamic Output Impedance (Note 6)	VZ = VREF, LM431A,				0.75	Ω
		Frequency = 0 Hz (Figure 1 )
		VZ = VREF, LM431B, LM431C				0.50	Ω
		Frequency = 0 Hz (Figure 1 )

Note 2: 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 3: TJ Max = 150ÊC.

Note 4: Ratings apply to ambient temperature at 25ÊC. Above this temperature, derate the TO-92 at 6.2 mW/ÊC, the SO-8 at 6.5 mW/ÊC, the SOT-23 at 2.2 mW/ÊC and the micro SMD at 3mW/ÊC.

Note 5: Deviation of reference input voltage, VDEV, is defined as the maximum variation of the reference input voltage over the full temperature range.

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