Microsemi Corporation LX6431IDM, LX6431CLP, LX6431CDM, LX6431BILP, LX6431BIDM Datasheet

		LX6431/LX6431A/LX6431B
		P R E C I S I O N P R O G R A M M A B L E R E F E R E N C E S
T H E I N F I N I T E P O W E R O F I N N O V A T I O N		P R O D U C T I O N D A T A S H E E T

D E S C R I P T I O N

The LX6431 series precision adjustable three terminal shunt voltage regulators are pin-to-pin compatible with the industry standard TL431, but with significant improvements. The LX6431 design has eliminated regions of instability common to older generation shunt regulator products like the TL431. Designs are made simpler by eliminating the task of insuring capacitive loads, and output voltage and cathode currents don't combine for unstable operation. The capacitor value is chosen simply to give the best load transient response without the possibility of instability. A lower reference input current allows the use of higher value reference divider resistors,

reducing the current drain from batteries in portable equipment as well as reducing the voltage programming errors due to the impedance of the divider network (See Product Highlight figure below). In addition, the LX6431B has an improved initial accuracy of 0.4%, and the output voltage is programmable by using two external resistors from 2.5V to 36V.

These devices offer low output impedance for improved load regulation. The typical output impedance of these devices is 100mΩ . The reduced reference input bias current and minimum operating currents make these devices suitable for portable and micropower applications.

K E Y F E AT U R E S

■Unconditionally Stable For All Cathode To

Anode Capacitance Values

■Reduced Reference Input Current Allowing

The Use Of Higher Value Divider Resistors

(0.5µA Max.)

■Initial Voltage Reference Accuracy Of 0.4%

(LX6431B)

■Sink Current Capability 0.6mA to 100mA

■Typical Output Dynamic Impedance Less

Than 100mΩ

■Adjustable Output Voltage From 2.5V to

36V

NOTE: For current data & package dimensions, visit our web site: http://www.linfinity.com.
								P R O D U C T H I G H L I G H T
			O U T P U T V O L TA G E E R R O R D U E T O I R E F
	20										T Y P I C A L P R O G R A M M A B L E V O L T A G E
												R E F E R E N C E C I R C U I T
	18
	16										VIN	VKA
	14											R1
Error	12
	10											LX6431
%
	8
												R2
	6
	4
	2											GND
	0
	2.5	3.75	5	6.25
					7.5
						8.75
							10
								11.25
									12.5
										13.75
				(VKA)	Output Voltage - (V)						15
						PA C K A G E O R D E R I N F O R M AT I O N

				Initial			Plastic SOIC			Plastic TO-92
	TA (°C)					DM			LP
				Tolerance			8-pin			3-pin
				2%			LX6431CDM			LX6431CLP
	0 to 70			1%			LX6431ACDM			LX6431ACLP
				0.4%			LX6431BCDM			LX6431BCLP
				2%			LX6431IDM			LX6431ILP
	-40 to 85			1%			LX6431AIDM			LX6431AILP
				0.4%			LX6431BIDM			LX6431BILP

Copyright © 1999

Rev. 1.4 6/99

Note: All surface-mount packages are available in Tape & Reel.

Append the letter "T" to part number. (i.e. LX5212CDPT)

TO-92 (LP) package also available in ammo-pack.

L I N F I N I T Y M I C R O E L E C T R O N I C S I N C .	1
11861 WESTERN AVENUE, GARDEN GROVE, CA. 92841, 714-898-8121, FAX: [phone]

P R O D U C T D A T A B O O K 1 9 9 6 / 1 9 9 7

LX6431/LX6431A/LX6431B

P R E C I S I O N P R O G R A M M A B L E R E F E R E N C E S

P R O D U C T I O N D A T A S H E E T

	ABSOLUTE MAXIMUM RATINGS	(Note 1)
	Cathode to Anode Voltage (VKA) ...................................................................	-0.3V to 37V
	Reference Input Current (IREF) ....................................................................	-50µA to 10µA
	Continuous Cathode Current (IK) .........................................................	-100mA to 150mA
	Operating Junction Temperature
	Plastic (DM & LP Packages) .................................................................................	150°C
	Storage Temperature Range ......................................................................	-65°C to 150°C
	Lead Temperature .....................................................................................................	300°C

Note 1. Exceeding these ratings could cause damage to the device. All voltages are with respect to Ground. Currents are positive into, negative out of the specified terminal. Pin numbers refer to DIL packages only.

THERMAL DATA

DM PACKAGE:

THERMAL RESISTANCE-JUNCTION TO AMBIENT, θ JA	165°C/W
LP PACKAGE:
THERMAL RESISTANCE-JUNCTION TO AMBIENT, θ JA	156°C/W

PACKAGE PIN OUTS

CATHODE				1	8			REF
N.C.				2	7			ANODE
ANODE				3	6			ANODE
N.C.				4	5			N.C.

DM PACKAGE

(Top View)

1. CATHODE

2. ANODE

3. REF

LP PACKAGE

(Top View)

Junction Temperature Calculation: TJ = TA + (PD x θ JA).

The θ JA numbers are guidelines for the thermal performance of the device/pc-board system. All of the above assume no ambient airflow

BLOCK DIAGRAM

Cathode (K)

Ref (R)

VREF

Anode (A)

2		Copyright © 1999
		Rev. 1.4 6/99

P R O D U C T D A T A B O O K 1 9 9 6 / 1 9 9 7

LX6431/LX6431A/LX6431B

P R E C I S I O N P R O G R A M M A B L E R E F E R E N C E S

P R O D U C T I O N D A T A S H E E T

E L E C T R I C A L C H A R A C T E R I S T I C S (Note 2)

(Unless otherwise specified, these specifications apply over the operating ambient temperatures for LX6431C/LX6431AC/LX6431BC with 0°C ≤ TA ≤ 70°C, LX6431I/LX6431AI/LX6431BI with -40°C ≤ TA ≤ 85°C.)

	Parameter				Symbol	Test Conditions	LX6431				Units
							Min. Typ. Max.
Reference Input Voltage				LX6431	VREF	IK = 10mA, VKA = VREF, TA = 25°C,	2440			2550	mV
				LX6431A		IK = 10mA, VKA = VREF, TA = 25°C	2470			2520	mV
				LX6431B		IK = 10mA, VKA = VREF, TA = 25°C	2490			2510	mV
Reference Drift				LX6431		IK = 10mA, VKA = VREF, 0°C ≤ TA ≤ 70°C				15	mV
						IK = 10mA, VKA = VREF, -40°C ≤ TA ≤ 85°C				25	mV
				LX6431A		IK = 10mA, VKA = VREF, 0°C ≤ TA ≤ 70°C				15	mV
						IK = 10mA, VKA = VREF, -40°C ≤ TA ≤ 85°C				25	mV
				LX6431B		IK = 10mA, VKA = VREF, 0°C ≤ TA ≤ 70°C				15	mV
						IK = 10mA, VKA = VREF, -40°C ≤ TA ≤ 85°C				20	mV
Voltage Ratio, Reference to Cathode						IK = 10mA, VKA = 2.5V to 36V, TA = 25°C		0.3		1	mV/V
(Note 3)						IK = 10mA, VKA = 2.5V to 36V, TA = Operating Range		0.3		1	mV/V
Reference Input Current					IREF	VKA = VREF, TA = 25°C		0.1		0.5	µA
						VKA = VREF, TA = Operating Range		0.1		0.5	µA
Minimum Operating Current					IMIN	VKA = VREF to 36V, TA = 25°C		0.4		0.6	mA
						VKA = VREF to 36V, TA = Operating Range		0.4		0.6	mA
Off-State Cathode Current					IOFF	VKA = 36V, VREF = 0V, TA = 25°C		0.3		1	µA
Dynamic Impedance					ZKA	VKA = VREF, IK = 0.6mA to 100mA, f ≤ 1kHz, TA = 25°C		30		100	mΩ
Note 2. These parameters are guaranteed by design.
Note 3.	∆ VREF		Ratio of change in reference input voltage
	∆ VKA
			to the change in cathode voltage.

Copyright © 1999	3
Rev. 1.4 6/99

P R O D U C T D A T A B O O K 1 9 9 6 / 1 9 9 7

LX6431/LX6431A/LX6431B

P R E C I S I O N P R O G R A M M A B L E R E F E R E N C E S

P R O D U C T I O N D A T A S H E E T

GRAPH / CURVE INDEX

Characteristic Curves

FIGURE #

1.REFERENCE VOLTAGE vs. FREE-AIR TEMPERATURE

2.REFERENCE CURRENT vs. FREE-AIR TEMPERATURE

3.CATHODE CURRENT vs. CATHODE VOLTAGE

4.OFF-STATE CATHODE CURRENT vs. FREE-AIR TEMPERATURE

5.RATIO OF DELTA REFERENCE VOLTAGE TO DELTA CATHODE VOLTAGE vs. FREE-AIR TEMPERATURE

6.EQUIVALENT INPUT NOISE VOLTAGE vs. FREQUENCY

FIGURE INDEX

Application Information

FIGURE #

7.COMPARISON OF REFERENCE RESISTOR VALUES BETWEEN AN LX6431B AND A TL1431. Resistors used with the LX6431B are 5 times higher in value.

8.COMPARISON OF REFERENCE RESISTOR VALUES BETWEEN AN LX6431B AND A TL1431. When used as 0.5%, 5V shunt regulators.

Parameter Measurement Information

FIGURE #

9.TEST CIRCUIT FOR VKA = VREF

10.TEST CIRCUIT FOR VKA > VREF

11.TEST CIRCUIT FOR IOFF

Typical Characteristics

FIGURE #

12.EQUIVALENT INPUT NOISE VOLTAGE OVER A 10-SECOND PERIOD

13.SMALL-SIGNAL VOLTAGE AMPLIFICATION vs. FREQUENCY

14.REFERENCE IMPEDANCE vs. FREQUENCY

15.PULSE RESPONSE

16.DIFFERENTIAL VOLTAGE AMPLIFICATION vs. FREQUENCY

4		Copyright © 1999
		Rev. 1.4 6/99