L2949E(8SOP) [UTC]

Regulator, 1 Output, BIPolar, PDSO8,;


型号：	L2949E(8SOP)
厂家：	Unisonic Technologies
描述：	Regulator, 1 Output, BIPolar, PDSO8, 光电二极管
文件：	总7页 (文件大小：135K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

UTCL2949E

LINEAR INTEGRATED CIRCUIT

MULTIFUNCTION VERY LOW

DROP VOLTAGE REGULATOR

DESCRIPTION

The UTC L2949E is a monolithic integrated 5V voltage

regulator with a very low dropout output and additonal

functions as power-on reset and input voltage sense.It is

designed for supplying the microcomputer controlled

systems especially in automotive applications.

DIP-8

SOP-8

FEATURES

*Operating dc supply voltage range 5V to 28V.

*Transient supply voltage up to 40V.

*Extremely low quiescent current in standby mode.

*High precision standby output voltage 5V±1%

SOP-20

*Output current capability up to 100mA.

*Very low dropout voltage less than 0.5V.

*Reset circuit sensing the output voltage

*Programmable reset pulse delay with external capacitor

*Voltage sense comparator.

*Thermal shutdown and short circuit protections.

PIN CONNECTIONS

N.C.

GND

N.C.

VOUT

GND

N.C.

RES

GND

VOUT

DIP-8/SOP-8

RES

SOP-20

UTC UNISONIC TECHNOLOGIES CO. LTD

QW-R102-014,A

UTCL2949E

LINEAR INTEGRATED CIRCUIT

BLOCK DIAGRAM

VOUT

PREREGULATOR 5V

2μ

RES

REG

REF

RESET

1.23V

SENSE

GND

ABSOLUTE MAXIMUM RATINGS

PARAMETER

DC Operating Supply Voltage

Transient Supply Voltage(T<1s)

Output Current

SYMBOL

VCC

VCC TR

RATING

UNIT

Internally Limited

Output Voltage

V^RES

Vso

Reset Output

Sense Output

Output Current

Reset Output

I^RES

Iso

Sense Output

Preregulator Output Voltage

Preregulator Output Current

Junction Temperature

Storage Temperature Range

℃

-40～+150

-55～+150

℃

Tstg

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QW-R102-014,A

UTCL2949E

DESCRIPTION

Thermal Resistance Junction-ambient

LINEAR INTEGRATED CIRCUIT

THERMAL DATA

SYMBOL

RATING

UNIT

DIP-8

SOP-8

SOP-20

100

200

℃/W

Rth j-amb

℃/W

℃

Thermal Resistance Junction-pin (SOP-20)

Thermal Shutdown Junction temperature

Rth j-pins

TJSD

165

ELECTRICAL CHARACTERISTICS(Vs=14V;-40℃<Tj<125℃ unless otherwise specified)

PARAMETER

Output Voltage

SYMBOL

CONDITIONS

Tj=25℃;Io=1mA

MIN

4.95

4.90

4.75

TYP.

MAX

5.05

5.10

5.25

UNIT

Output Voltage

6V<VIN<28V,1mA<Io<50mA

VIN=40V;

T<1s 5mA<Io<100mA

Io=10mA

Dropout voltage

0.1

0.2

0.3

0.25

0.4

Io=50mA

Io=100mA

VIN=4V,Io=35mA

0.5

0.4

Input to Output Voltage

Difference in Undervoltage

Condition

V^IO

μA

Max Output Leakage

Iouth ** VIN=25V,Vo=5.5V

Line Regulation

Load Regulation

Current Limit

VOL

VOLO

ILIM

6V<VIN<28V, Io=1mA

1mA<Io<100mA

Vo=4.5V

Vo=4.5V,TJ=25℃

Vo=0V(note 1)

Io=0.3mA;TJ<100℃

Io=100mA

400

105

120

200

100

200

μA

Quiescent Current

IQSE

300

** With this test we guarantee that with no output current the output voltage will not exceed 5.5V

RESET

PARAMETER

Reset Thereshold Voltage

Reset Thereshold Hysteresis

Reset Pulse Delay

SYMBOL

VRT

VRTH

tRD

CONDITIONS

MIN

TYP.

Vo-0.5V

100

MAX

UNIT

200

180

0.4

CT=100nF;TR≧100μs

RRES=10KΩ to Vs≧1.5V

VRES=5V

100

Reset Output Low Voltage

Reset Output Gigh Leakage

Current

VRL

IRH

μA

Delay Comparator Thereshold

Delay Comparator Thereshold VCTth,hy

Hysteresis

VCTth

100

UTC UNISONIC TECHNOLOGIES CO. LTD

QW-R102-014,A

UTCL2949E

LINEAR INTEGRATED CIRCUIT

SENSE

PARAMETER

SYMBOL

Vst

CONDITIONS

MIN

1.16

TYP.

1.23

100

MAX

1.35

200

0.4

UNIT

Sense Low Thereshold

Sense Thereshold Hysteresis

Sense Output Low Voltage

Vsth

VSL

VSI≦1.16V;Vs≧3V

Rso=10KΩ to Vo

Vso=5V;VSI≧1.5V

VSI=0

μA

Sense Output Leakage

Sense Input Current

ISH

ISI

-3

-20

-8

PREREGULATOR

PARAMETER

Preregulator Output Voltage

Preregulator Output Current

Note 1:Foldback characteristic

SYMBOL

CONDITIONS

Iz=10μA

MIN

4.5

TYP.

MAX

UNIT

μA

APPLICATION CIRCUIT

VOUT

Vz (optional)

VBAT

PREREGULATOR 5V

RES

2μ

VOUT

REG

RESET

1.23V

REF

1.23V

GND

SENSE

For stability:Cs≧1μF, Co ≧4.7μF, ESR<10Ωat 10KHz

Recommended for application:Cs=Co=10µF to 100µF

APPLICATION INFORMATION

Suppl Voltage Transient

High supply voltage transients can cause a reset output signal disturbation.

For supply voltage greater than 8V the circuit shows a high immunity of the reset output against supply transients of

the reset output against supply transients of more than100V/μs.

For supply voltages less than 8V supply transients of more than 0.4V/μs can cause a reset signal disturbation.

To improve the transient behaviour for supply voltages less than 8V a capacitor at pin 3 can be used.

A capacitor at pin 3(C3≦1μF ) reduces also the output noise.

UTC UNISONIC TECHNOLOGIES CO. LTD

QW-R102-014,A

UTCL2949E

LINEAR INTEGRATED CIRCUIT

FUNCTIONAL DESCRIPTION

The UTC L2949E is a monolithic integrated voltage regulator,based on the STM modular voltage regulator

approch.Several outstanding features and auxiliary functions are implemented to meet the requirements of supplying

microprocessor systems in automotive applications.Nevertheless,It is suitable also in other applications where the

present functions are required.The modular approach of this device allows to get easily also other features and

functions when required.

Voltage Regulator

The voltage regulator uses an lsolated Collector Vertical PNP transistor as a regulating element.

200

100

IOUT(mA)

Figure 1: Foldback Characteristic of Vo

With this structure very low dropout voltage at currents up to 100mA is obtained.The dropout operation of the

standby regulator is maintained down to 3V input supply voltage.The output voltage is regulated up to the transient

input supply voltage of 4V.With this feature no functional interruption due to overvoltage pulses is generated.The

typical cuve showing the standby.output voltage as a function of the input supply voltage is shown in Fig.2. The

current consumption of the device(quiescent current) is less than 300μA.

To reduce the quiescent current peak in the undervoltage region and to improve the transient response inthis

region.the dropout voltage is controlled,the quiescent current as a function of the supply input voltage is shown in

Fig.3.

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QW-R102-014,A

UTCL2949E

LINEAR INTEGRATED CIRCUIT

2.0

RL=100Ω

1.5

VOUT

1.0

0.5

VOUT

RL=4.7KΩ

40V

28V

Figure 2: Output Voltage vs.Input voltage

Figure 3: Quiescent Current vs.Supply Voltage

Preregulator

To improve the transient immunity a preregulator stabilized the internal supply voltage to 5V.This internal voltage is

present at Pin3(Vz).This voltage should not be used as an output because the output capability is very small(≦10μ

A).

This output may be used as an option when a better transient behaviour for supply voltages less than 8V is

required(see also application note).

In this case a capacitor(100nF - 1μF) must be connected between Pin3 and GND.If this feature is not used Pin3

must be left open.

Reset Circuit

The block circuit diagram of the reset circuit is shown in Fig.4. the reset circuit supervises the output voltage.

The reset thereshold of 4.5V is defined with the internal reference voltage and standby output drivider.

The reset pulse delay time t^RD,is defined with the charge time of an external capacitor CT:

CT● 2V

TRD=

2μA

The reaction time of the reset circuit originates from the discharge time limitation of the reset capacitor CT and is

proportional of the reset capacitor CT and is proportional to the value of CT.

The reactioin time of the reset circuit increases the noise immunity.Standby output voltagedrops below the reset

threshold only a bit longer than th reaction time results in a shorter reset delay time.

The nominal reset delay time will be generated for standby output voltage drops longer than approximately 50μs.

The typical reset output waveforms are shown in Fig.5.

Sense Comparator

The sense comparator compares an input signal with an internal voltage reference of typical 1.23V.The use of an

external voltage divider makes this comparator flexible in th application.

It can be used to supervise the input voltage either before or after the protection diode and to give additional

informations to the microprocessor like low voltage warnings.

UTC UNISONIC TECHNOLOGIES CO. LTD

QW-R102-014,A

UTCL2949E

LINEAR INTEGRATED CIRCUIT

1.23V

22K

REF

RESET

OUT

REG

2.8V

Figure 4

40V

VOUT

VIN

VOUT1

5.0V

VRT+0.1V

VRT

1.5V

RESET

tRD

tRR

tRD

SWITCH ON

OUTPUT

SWITCH OFF

INPUT DROP

DUMP

OVERLOAD

Figure 5

UTC assumes no responsibility for equipment failures that result from using products at values that

exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or

other parameters) listed in products specifications of any and all UTC products described or contained

herein. UTC products are not designed for use in life support appliances, devices or systems where

malfunction of these products can be reasonably expected to result in personal injury. Reproduction in

whole or in part is prohibited without the prior written consent of the copyright owner. The information

presented in this document does not form part of any quotation or contract, is believed to be accurate

and reliable and may be changed without notice.

UTC UNISONIC TECHNOLOGIES CO. LTD

QW-R102-014,A

L2949E(8SOP) [UTC]

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