IRU431LCL3TR [INFINEON]

暂无描述;


型号：	IRU431LCL3TR
厂家：	Infineon
描述：	暂无描述稳压器电源电路参考电压源光电二极管输出元件
文件：	总6页 (文件大小：49K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

Data Sheet No. PD94118

IRU431L / IRU431AL

LOW -VOLTAGE ADJUSTABLE PRECISION

SHUNT REGULATOR

FEATURES

DESCRIPTION

The IRU431L family are three-terminal adjustable shunt

regulators that can also be used as precision voltage

SOT-23 Packages

Voltage Reference Initial Accuracy

(1% for IRU431L and 0.5% for IRU431AL)

Low Operating Cathode Current

(80µA max)

Unconditionally Stable with only 1µF

Adjustable Output from 1.24V to 15V

0.25Ω Typical Output Impedance

Pin to Pin Compatible with TLV431

references. Its output voltage may be set to any value

between VREF(1.24V) and 15V with two external resis-

tors as shown in the typical application circuit. Other

applications of this device include being used as a

merged amplifier and reference in applications such as

a linear regulator or as the secondary side controller in

low voltage power supply applications. The IRU431L only

requires 80µA maximum quiescent current before regu-

lating, making it ideal as a voltage reference for battery

type applications. The IRU431L has ±1% initial accu-

racy while IRU431AL provides ±0.5% initial accuracy.

APPLICATIONS

Precision Voltage Reference

Linear Regulator Controller

Secondary Side Controller for the low voltage

power supply applications

TYPICAL APPLICATION

VIN

VOUT

IRU431L

Vo = VREF ×o 1 +

Figure 1 - Typical application of the IRU431L as a shunt regulator / voltage reference.

PACKAGE ORDER INFORMATION

TA (°C)

0 To 70

5-PIN SOT-23 (L5)

IRU431LCL5

IRU431ALCL5

3-PIN SOT-23 (L3)

IRU431LCL3

IRU431ALCL3

Rev. 1.8

02/20/02

www.irf.com

IRU431L / IRU431AL

ABSOLUTE MAXIMUM RATINGS

Input Voltage (VIN) .................................................... 15V

Continuous Cathode Current Range .......................... -15mA To +15mA

Reference Current Range .......................................... -0.05mA To 1mA

Storage Temperature Range ...................................... -658C To 1508C

Operating Junction Temperature Range .....................

08C To 1508C

PACKAGE INFORMATION

5-PIN SOT-23 (L5)

3-PIN SOT-23 (L3)

TOP VIEW

Cathode

Anode

Ref

Cathode

Ref

qJA=256°C/W

qJA=336°C/W

ELECTRICAL SPECIFICATIONS

Unless otherwise specified, these specifications apply over TA=0 to 708C, Co=1µF. Typical values refer to TA=258C.

Low duty cycle pulse testing is used which keeps junction and case temperatures equal to the ambient tempera-

ture.

PARAMETER

SYM

TEST CONDITION

MIN

TYP

MAX UNITS

Reference Voltage

IRU431L

Reference Voltage

IRU431AL

VREF

IK=10mA, VKA=VREF, TA=258C

IK=10mA, VKA=VREF

IK=10mA, VKA=VREF, TA=258C

IK=10mA, VKA=VREF

VKA=VREF, IK=10mA

Note 1

1.228 1.240 1.252

1.221 1.240 1.259

1.234 1.240 1.246

1.228 1.240 1.252

VREF

VREF Deviation over full

temperature range

Ratio of VREF change to

cathode voltage change

Reference Pin Current

IREF Deviation over full

temperature range

Minimum Cathode Current

Off State Cathode Current

VREF(DEV)

mV/V

∆VREF/∆VKA IK=10mA, ∆VKA=VREF to 6V

-1

-6

IK=10mA, R1=10KΩ, R2=open

Note 1

0.15

0.05

µA

IREF(DEV)

IK(MIN)

Ioff

VKA=VREF

0.6

1.8

3.2

0.25

0.75

0.4

µA

VKA=6V, VREF=0V

VKA=10V, VREF=0V

VKA=15V, VREF=0V

VKA=VREF, f<1KHz,

IK=0.1 to 15mA, Note 2

Dynamic Impedance

ZKA0

Ω

Note 1: The deviation parameters, VREF(DEV) and IREF(DEV) Where:

are defined as the differences between the maximum ?αVREF? unit is ppm/8C

and the minimum values obtained over the rated tem- ∆TA is the rated operating free air temperature of the

perature range. The average full range temperature coef- device.

ficient of the reference input voltage is defined as:

αVREF can be positive or negative depending on whether

minimum VREF or maximum VREF respectively occurs at

the lower temperature.

VREF(DEV)

VREF(258C)

× 10⁶

?αVREF? =

∆TA

Rev. 1.8

02/20/02

www.irf.com

IRU431L / IRU431AL

Note 2: The dynamic impedance when VKA=VREF is de- When the device is operating with two external resistors

fined as:

(See figure 3), the total dynamic impedance of the cir-

cuit is given by:

∆VKA

∆IK

?ZKA0? =

∆V

∆I

?ZKA? =

= ?ZKA0? ×o 1 +

PIN DESCRIPTIONS

SOT-23

3-PIN

PIN#

SOT-23

5-PIN

PIN#

PIN SYMBOL

PIN DESCRIPTION

Ref

Resistors from the Ref pin to the Cathode pin and to ground form a divider

that sets the output voltage.

Cathode

Anode

The output of the shunt regulator. A capacitor of 1µF minimum value must

be connected from this pin to Anode pin to insure unconditional stability.

Ground pin. This pin must be connected to the lowest potential in the

system and all other pins must be at higher potential with respect to this

pin.

1, 2

These pins are not connected internally.

BLOCK DIAGRAM

Cathode

Ref

1.24V

Anode

Figure 2 - Simplified block diagram of the IRU431L.

Rev. 1.8

02/20/02

www.irf.com

IRU431L / IRU431AL

APPLICATION INFORMATION

Output Voltage Setting

An example is given below on how to properly select the

The IRU431L can be programmed to any voltages in the biasing resistor.

range of 1.24 to 15V with the addition of R1 and R2

external resistors according to the following formula:

Assuming:

VMIN = 4.5V

VMAX = 6V

VKA = 3.3V

IL = 10mA

Vo = VKA = VREF ×o 1 +

p + IREF × R1

The IRU431L keeps a constant voltage of 1.240V be-

tween the Ref pin and ground pin. By placing a resistor The maximum value for the biasing resistor is calcu-

R2 across these two pins a constant current flows lated using the following equations:

through R2, adding to the IREF current and into the R1

resistor producing a voltage equal to:

VMIN - VKA

IB(MAX) + IL(MAX)

RB(MAX) =

1.240

IB(MAX) = IK(MIN) + IR

p × R1 + IREF × R1

Where:

which will be added to the 1.240V to set the output volt-

age as shown in the above equation. Since the input

bias current of the Ref pin is 0.5µA max, it adds a very

small error to the output voltage and for most applica-

tions can be ignored. For example, in a typical 5V to

3.3V application where R2=1.21KΩ and R1=2KΩ the

error due to the IADJ is only 1mV which is about 0.03% of

the nominal set point.

VMIN = Minimum supply voltage

IL(MAX) = Maximum load current

IB(MAX) = Maximum bias current

IK(MIN) = Maximum value for the minimum

cathode current spec

IR = Current through R1

Assuming R1 = 2KΩ as before,

3.3 - 1.24

IR =

= 1.03mA

VKA = VOUT

IB(MAX) = 0.08 + 1.03 = 1.11mA

4.5 - 3.3

IRU431L

RB(MAX) =

= 108Ω

1.11 +10

Select RB = 100Ω

Figure 3 - Typical application of the

IRU431L for programming the output voltage.

The maximum power dissipation of the resistor is

calculated under the maximum supply voltage as

follows:

(VMAX - VKA)²

Biasing Resistor (RB) Selection

PRB(MAX) =

The biasing resistor RB is selected such that it does not

limit the input current under the minimum input supply

and maximum load and biasing current.

Where:

VMAX = Maximum supply voltage

PRB(MAX) = Maximum RB power dissipation

(6 - 3.3)²

100

PRB(MAX) =

= 73mW

Rev. 1.8

02/20/02

www.irf.com

IRU431L / IRU431AL

Thermal Design

Stability

The IRU431L is offered in the surface mount SOT-23 (L) The IRU431L has many different domains of stability as

packages. The SOT-23 package has the maximum power a function of the cathode current. As is typical of three-

dissipation capability of 150mW at TA=25°C with the de- terminal shunt regulators, the IRU431L has many do-

rating factor of -1.2mW / °C.

mains of stability. The actual domain in which any prac-

tical circuit operates is related to cathode current. In

The table below summarizes the maximum power dissi- general the device will be unconditionally stable for any

pation capability of each package versus ambient tem- cathode current if a capacitor, 1µF or larger, is connected

perature.

between the cathode and the anode. If the cathode cur-

rent is always higher than 3mA under minimum line and

maximum load conditions, the capacitor value can be

reduced to 0.01µF and the system will be stable.

Ambient Temperature (TA) -8C

Pkg

SOT-23

150mW 132mW 120mW

108mW

96mW

In our previous example, the maximum power dissipa-

tion of the device is calculated under no load and maxi-

mum input supply condition.

The maximum power is calculated using the following

equation:

PMAX = VKA × o ^{VMAX - VKA}p

Where:

PMAX = Maximum power dissipation of the 431L

For our example:

6 - 3.3

PMAX = 3.3 × o

p = 89mW

100

As shown in the power dissipation table, both packages

can handle this power dissipation.

Rev. 1.8

02/20/02

www.irf.com

IRU431L / IRU431AL

TYPICAL APPLICATION

OUT

12V

Figure 4 - Low cost 3.3V to 2.7V output.

Ref Desig

C1, C2

Description

Shunt Regulator

Capacitor

Resistor

Qty

Part #

Manuf

IRU431L

Elect,220µF, 6.3V, ECAOJFQ221 Panasonic

6.2KΩ, 5%, SMT

Resistor

118Ω, 1%, SMT

R3, R4

HS1

Resistor

Heat Sink

100Ω, 1% SMT

Use minimum of 1" square copper pad area

for load current <4A

IR WORLD HEADQUARTERS:233 Kansas St., El Segundo, California 90245, USA Tel: (310) 252-7105

TAC Fax: (310) 252-7903

Visit us at www.irf.com for sales contact information

Data and specifications subject to change without notice. 02/01

Rev. 1.8

02/20/02

www.irf.com

IRU431LCL3TR [INFINEON]

相关型号：

IRU431LCL5

IRU431LCL5PBF

IRU431LCL5TR

IRU431LCL5TRPBF

IRU431LCS

IRU431LCSPBF

IRUD200CH20PBF

IRUD360CW40

IRUD360CW40PBF

IRUD400CW60

IRUH330118A

IRUH330118AK