AAC243E-D8A-G-LF_技术文档

Power Management AAC242/243

AAC242/243

PRELIMINARY DATA

Current Mode PWM Contoller

DESCRIPTION

The AAC242 and AAC243 are part of AAI’s new

family of specialty products for Power Management

applications. The AAC242 and AAC243 are high

performance integrated circuits designed for Off-line

or DC to DC converters using peak current mode

control. The AAC24X has a current sense of 250mV

in comparison to 1V for AAC14X parts.

In offline AC designs the startup is improved by the

low start-up current of the family. The integrated

soft-start function adds to the easy of using the

AAC24X parts in offline applications.

FEATURES

•

Low Start-up current

Pulse by pulse current limiting

The AAC242 and AAC243 are identical except for the

Under Voltage Lockout. The AAC242 has UVLO_on

threshold of 16V and off of 10V making it easy to use

in offline supplies where startup requirements for

energy storage is necessary. For applications using

lower supply voltages the AAC243 has UVLO_onof

8.4V and UVLO_offof 7.6V.

On board voltage reference

Under Voltage Lockout with hysteresis

Simple oscillator circuit

Over Voltage protection zener

High current output driver

Less than 30ns rise and fall times

Operation to over 1MHz

The AAC24X family is offered in DIP and SMD

packages. The packages are industry standards and

are ROHS compliant.

Extended temperature is

Peak Current Mode control

standard with the AAC24X family.

Integrated Soft-Start Function (~330 Clock

Cycles)

The greater than 1A output driver is ideal for driving

MOSFETs and low power IGBTs. Rise and fall times

are typically less that 30ns with a 1000pF load. The

improvements in switching speed can provide

improvements in efficiency, higher operating

frequency and over current protection.

•

100ns leading edge current blanking for reduced

filtering

250mV current sense

PIN CONFIGURATION: 8-Lead DIP and SOIC8

The AAC24X family has a minimum pulse width of

0.4% allowing operation at very low power without

pulse skipping or erratic operation. The narrower

pulse width capibilities enhances operation at higher

frequencies and voltages.

View of the AAC24X shown from the top.

COMP 1 8 VREF

AAC242

AAC243

Rt/Ct 4 5 GND

VFB

VCC

OUT

ISENSE

–

AADS00012 / R127B

-

Preliminary

-

October 2010 1 / 8

Power Management AAC242/243

BLOCK DIAGRAM

8 Vcc

5.00VREF

UVLO

2.5V

5V

REF

Vref 7

34V

DVR

5 GND

4 Rt/Ct

REF

OK

OSC

OUTPUT 6

Error

Amp

11R

2R

+

-

S

R

-

2 Vfb

Q

R

1V

+

Current Sense

Comparator

1 COMP

3 Isense

Open Loop Test Circuit

V+

A

Rt

4.7K

100K

0.1uF

1

8

7

6

5

COMP

Vref

Vcc

2N3904

2

3

4

FB

1K

1K/1W

OUTPUT

Isense

R/C

OUT

GND

5K

0.1uF

4.7K

Ct

MAXIMUM RATINGS

PARAMETER

PARAMETERS

UNITS

CONDITIONS

MIN.

MAX.

Supply Voltage (V_cc– Ground)

V_fband I_senseAmp Inputs

Output Current

0

30

V

A

Low impedance source

-0.3

5.5

±1

1200

1000

150

mW

°C

DIP

Power Dissipation

SOIC8

Operating Junction Temperature

Operating Ambient Temperature

Extended industrial temp. rated

devices

-40

105

°C

Operating Ambient Temperature

Storage Temperature Range

Lead Temperature (10 Second)

-40

-65

125

150

300

°C

Automotive temp. rated devices

Soldering

–

AADS00012 / R127B

-

Preliminary

-

October 2010 2 / 8

Power Management AAC242/243

ELECTRICAL CHARACTERISTICS

Unless otherwise stated, T=25C, Vcc=15V, R_T= 10KΩ, C_T= 3300pF.

PARAMETER

PARAMETERS

UNITS

CONDITIONS

MIN.

TYP.

MAX.

REFERENCE SECTION

V

Output Voltage

4.95

5.00

6

5.05

15

Line Regulation

mV

12V<V_cc<25V

0C to 130C

Load Regulation

3

25

Temperature Stability

0.2

mV/°C

V

Total Output Variation

Long Term Stability

4.9

-30

47

5.1

-60

Line, Load, and Temperature

T_a=125°C for 1000 hours

5

mV

Output Short Circuit Current

OSCILLATOR SECTION

Frequency Initial Accuracy

Frequency Change with Voltage

Frequency Change with Temp.

Oscillator Voltage Swing

ERROR AMPLIFIER SECTION

Voltage Feedback Input

Input Bias Current

-50

mA

52

0.2

1

57

1

KHz

%

Ta=25°C

12<Vcc<25V

T_low<T_a<T_high

%

1.65

V_pp

2.45

2.5

2.55

-1

V

µA

dB

MHz

dB

mA

V

V_out=2.5V

Open Loop Voltage Gain

Unity Gain Bandwidth

Power Supply Rejection Ratio

Output Current Sink

90

10

70

12

-1

T_j=25°C

12V<V_cc<25V

Output Current Source

Output Voltage Swing High

Output Voltage Swing Low

6

0.8

V

PULSE WIDTH MODULATION SECTION

Maximum Duty Cycle

97

%

Minimum Duty Cycle

0.4

Before drop out

CURRENT SENSE SECTION

Voltage Gain

11.4

242

12.0

250

70

12.6

258

V

Maximum Input Signal

Power Supply Rejection Ratio

Input Bias Current

mV

dB

µA

nS

-10

300

Time Delay to Output

–

AADS00012 / R127B

-

Preliminary

-

October 2010 3 / 8

Power Management AAC242/243

PARAMETER

PARAMETERS

TYP.

UNITS

CONDITIONS

MIN.

MAX.

OUTPUT SECTION

Voltage Out Low

0.4

2.2

V

Isink = 20mA

Isink = 200mA

Isink = 20mA

Voltage Out Low

Voltage Out High

13.5

12.5

14

V

Voltage Out High

13.5

V

Isink = 200mA

Vcc=6V, Isink = 1mA

C_L=1000pF

Voltage Out UVLO

1.1

50

V

Voltage Output Rise Time

Voltage Output Fall Time

Current Output Source Peak

Current Output Sink Peak

30

ns

A

C_L=1000pF

1.2

0.7

A

UNDER-VOLTAGE LOCKOUT SECTION

Voltage Start Threshold (142)

Voltage Start Threshold (143)

Voltage Turnoff Threshold (142)

Voltage Turnoff Threshold (143)

Zener Clamp Voltage

15

7.8

9

16

8.4

10

17

9

V

11

8.2

7

7.6

34

30

I_cc≤25mA

TOTAL DEVICE SECTION

Start-up Supply Current

0.4

0.6

11

mA

Operating Supply Current

The improved switching performance increases the high peak current associated with internal and external

capacitances and will require careful grounding and PCB trace routing. Bypass and timing capacitors should be of

high quality and located carefully with short traces. The reference capacitor must be located very close to the IC

with minimum trace lengths. A single point ground should be located at pin 5 ground. The use of a good ground

plane is recommended. Under certain conditions of high peak currents it may be advisable to isolate the Vref pin

from the bypass capacitor with a resistor to prevent interaction of the high current with the internal oscillator

operation.

Charge and discharge times are given by the following formulas:

T_C=0.55R_tC_t

T_D=R_tC_tLn[(0.0063R_t-2.7)/(0.0063R_t-4)]

Frequency =( T_C+ T_D)^-1

Oscillator simplified circuit.

1

2

3

4

8

7

6

5

COMP

FB

Vref

Vcc

Rt

Ct

Isense

R/C

OUT

GND

–

AADS00012 / R127B

-

Preliminary

-

October 2010 4 / 8

Power Management AAC242/243

Oscillator Frequency as a function of Rt and Ct

Dead/delay time verses Ct

Ct Capacitance in nF

Oscillator frequency in KHz

Peak current is set by the internal comparator with a fixed limit of 0.250V. Raising the current sense pin (3) to

0.250V or higher will cause a termination of the output pulse regardless of the error amplifier output. The peak

current is normally determined when the current sense pin exceeds the error amplifier conditioned output. Peak

current is determined by the formula:

I_SENSE(PK)= 0.250V/R_S

In some cases where leading edge switching transients exceed the 100ns blanking, a small RC filter will be required.

RC filter

1

2

3

4

8

7

6

5

COMP

FB

Vref

Vcc

Isense

R/C

OUT

GND

R

C

Rsense

–

AADS00012 / R127B

-

Preliminary

-

October 2010 5 / 8

Power Management AAC242/243

In cases where duty cycle exceeds 50% slope compensation is required. This can be implemented by adding a buffer

transistor to the oscillator circuit and using a resistive summing circuit to provide the ramp necessary for slope

compensation.

Slope compensation

Rt

2N3904

Rslope

1

2

3

4

8

7

6

5

COMP

FB

Vref

Vcc

Isense

R/C

OUT

GND

R

C

Rsense

Ct

Shut down circuits depend on the desired function. A transistor can be used to allow control on and off of the PWM

or an SCR can be used to latch off the PWM.

Shutdown circuits

100K

1

2

3

4

8

7

6

5

1

8

7

6

5

COMP

FB

Vref

Vcc

COMP

FB

Vref

Vcc

2

3

4

Isense

R/C

OUT

GND

Isense

R/C

OUT

GND

shutdown

2N3904

shutdown

2N3904

–

AADS00012 / R127B

-

Preliminary

-

October 2010 6 / 8

Power Management AAC242/243

Ordering Information

Ordering PN(1)

Subgroup Description

Temp. Range

Package

Packing Type

Packing Qty

AAC242E‐D8A‐G‐LF

Controller

Current Mode,

Offline Thresholds

Ext. Industrial

8‐Pin DIP

Tube

50

AAC242A‐D8A‐G‐LF

AAC242E‐S8A‐G‐LF

AAC242E‐S8A‐G‐LF‐TR

AAC242A‐S8A‐G‐LF

AAC242A‐S8A‐G‐LF‐TR

AAC242E‐F8A‐G‐LF‐W

AC242E‐F8A‐G‐LF‐TR

AAC242A‐F8A‐G‐LF‐W

AC242A‐F8A‐G‐LF‐TR

AAC243E‐D8A‐G‐LF

AAC243A‐D8A‐G‐LF

AAC243E‐S8A‐G‐LF

AAC243E‐S8A‐G‐LF‐TR

AAC243A‐S8A‐G‐LF

AAC243A‐S8A‐G‐LF‐TR

AC243E‐F8A‐G‐LF‐W

AAC243E‐F8A‐G‐LF‐TR

AC243A‐F8A‐G‐LF‐W

AAC243A‐F8A‐G‐LF‐TR

Current Mode,

Offline Thresholds

Automotive

Ext. Industrial

Automotive

Ext. Industrial

Automotive

Ext. Industrial

Automotive

Ext. Industrial

Automotive

Ext. Industrial

Automotive

8‐Pin DIP

8‐Pin SOIC

Tube

50

98

Current Mode,

Offline Thresholds

Current Mode,

Offline Thresholds

13” T&R (2)

Tube

2500

98

Current Mode,

Offline Thresholds

Current Mode,

Offline Thresholds

13” T&R (2)

Waffle Pack

T&R (2)

2500

TBD

50

Current Mode,

Offline Thresholds

3mmx3mm

8‐Pin DFN

Current Mode,

Offline Thresholds

3mmx3mm

8‐Pin DFN

Current Mode,

Offline Thresholds

3mmx3mm

8‐Pin DFN

Waffle Pack

T&R (2)

Current Mode,

Offline Thresholds

3mmx3mm

8‐Pin DFN

Current Mode,

Battery Level Thresholds

8‐Pin DIP

Tube

Current Mode,

Battery Level Thresholds

Tube

50

Current Mode,

Battery Level Thresholds

8‐Pin SOIC

Tube

98

Current Mode,

Battery Level Thresholds

13” T&R (2)

Tube

2500

98

Current Mode,

Battery Level Thresholds

Current Mode,

Battery Level Thresholds

13” T&R (2)

Waffle Pack

T&R (2)

2500

TBD

Current Mode,

Battery Level Thresholds

3mmx3mm

8‐Pin DFN

Current Mode,

Battery Level Thresholds

3mmx3mm

8‐Pin DFN

Current Mode,

Battery Level Thresholds

3mmx3mm

8‐Pin DFN

Waffle Pack

T&R (2)

Current Mode,

3mmx3mm

Battery Level Thresholds

8‐Pin DFN

(1) Only RoHS/Lead‐Free Packaging is normally offered.

(2) T&R ‐ Tape and Reel

Package Dimensions and Marking

The AAC242 and AAC243 are available in a plastic 8-pin DIP or SOIC package. Refer to the latest version of

specification AAPS001 (ASIC Advantage’s “Package Numbering, Marking, and Outline Standard”, available at

www.asicadvantage.com) for specific information concerning the package dimensions and package marking.

–

AADS00012 / R127B

-

Preliminary

-

October 2010 7 / 8

Power Management AAC242/243

The following is a brief overview of certain terms and conditions of sale of product. For a full and complete copy of all

the General Terms and Conditions of Sale, visit our webpage http://www.asicadvantage.com/terms.htm.

LIMITED WARRANTY

The product is warranted that it will conform to the applicable specifications and be free of defects for one year.

Buyer is responsible for selection of, use of and results obtained from use of the product. Buyer indemnifies and

holds ASIC Advantage, Inc. harmless for claims arising out of the application of ASIC Advantage, Inc.’s products to

Buyer’s designs. Applications described herein or in any catalogs, advertisements or other documents are for

illustrative purposes only.

CRITICAL APPLICATIONS

Products are not authorized for use in critical applications including aerospace and life support applications. Use of

products in these applications is fully at the risk of the Buyer. Critical applications include any system or device

whose failure to perform can result in significant injury to the user.

LETHAL VOLTAGES

Lethal voltages could be present in the applications. Please comply with all applicable safety regulations.

INTELLECTUAL PROPERTY RIGHTS AND PROPRIETARY DATA

ASIC Advantage, Inc. retains all intellectual property rights in the products. Sale of products does not confer on

Buyer any license to the intellectual property. ASIC Advantage, Inc. reserves the right to make changes without

notice to the products at any time. Buyer agrees not to use or disclose ASIC Advantage Inc.’s proprietary information

without written consent.

TRADEMARKS AND PATENTS

- IN-PLUG® is a registered trademark of ASIC Advantage, Inc.

- AAI’s modified snubber network is patented under the US Patent # 6,233,165

PROTECTION FOR CUSTOM SOLUTIONS

When AAI accepts to design and manufacture products to Buyer’s designs or specifications, buyer has certain

obligations to provide defense in a suit or proceeding claiming infringement of a patent, copyright or trademark or for

misappropriation of use of any trade secrets or for unfair competition.

COMPLIANCE WITH LAWS

Buyer agrees that at all times it will comply with all applicable federal, state, municipal, and local laws, orders and

regulations. Buyer agrees to comply with all applicable restrictions on exports and re-exports including obtaining any

required U.S. Government license, authorization, or approval. Buyer shall pay any duties, levies, taxes, brokerage

fees, or customs fees imposed on the products.

TITLE AND DELIVERY

All shipments of goods shall be delivered ExWorks, Sunnyvale, CA, U.S.A. Title in the goods shall not pass to Buyer

until ASIC Advantage, Inc. has received in full all amounts owed by Buyer.

LATEST DATASHEET UPDATES

For the latest datasheet updates, visit our web page: http://www.asicadvantage.com.

WORLDWIDE REPRESENTATIVES

To access AAI’s list of worldwide representatives, visit our web page http://www.asicadvantage.com.

COPYRIGHTS

Copyrights and all other proprietary rights in the Content rests with ASIC Advantage Inc. (AAI) or its licensors. All

rights in the Content not expressly granted herein are reserved. Except as otherwise provided, the Content published

on this document may be reproduced or distributed in unmodified form for personal non-commercial use only. Any

other use of the Content, including without limitation distribution, reproduction, modification, display or transmission

without the prior written consent of AAI is strictly prohibited. All copyright and other proprietary notices shall be

retained on all reproductions.

ASIC Advantage INC.

1290-B Reamwood Ave, Sunnyvale California 94089, USA

Tel: (1) 408-541-8686 Fax: (1) 408-541-8675

Websites: http://www.asicadvantage.com

–

AADS00012 / R127B

-

Preliminary

-

October 2010 8 / 8


型号：	AAC243E-D8A-G-LF
厂家：	Microsemi
描述：	Switching Controller, Current-mode, 1A, PDIP8, DIP-8 开关光电二极管
文件：	总8页 (文件大小：201K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

AAC243E-D8A-G-LF [MICROSEMI]

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