INFINEON ICE2A0565, ICE2A165, ICE2A265, ICE2A365, ICE2B0565 User Manual

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Datasheet V4.5, Jan 2004

CoolSET™-F2

I C E 2 A 0 5 6 5 / 1 6 5 / 2 6 5 / 3 6 5 I C E 2 B 0 5 6 5 / 1 6 5 / 2 6 5 / 3 6 5 I C E 2 A 0 5 6 5 Z

I C E 2 A 1 8 0 Z / 2 8 0 Z

I C E 2 A 7 6 5 I / 2 B 7 6 5 I

I C E 2 A 7 6 5 P 2 / I C E 2 B 7 6 5 P 2

Off-Line SMPS Current Mode Controller with integrated 650V/800V CoolMOS™

P o w e r M a n a g e m e n t & S u p p l y

N e v e r s t o p t h i n k i n g .

CoolSET™-F2

 

 

 

Revision History:

2004-01-28

Datasheet V4.5

 

 

 

Previous Version:

 

 

 

 

 

Page

Subjects (major changes since last revision)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

For questions on technology, delivery and prices please contact the Infineon Technologies Offices in Germany or the Infineon Technologies Companies and Representatives worldwide: see our webpage at http:// www.infineon.com.

CoolMOS™, CoolSET™ are trademarks of Infineon Technologies AG.

Edition 2004-01-28

Published by Infineon Technologies AG, St.-Martin-Strasse 53,

D-81541 München

© Infineon Technologies AG 1999. All Rights Reserved.

Attention please!

The information herein is given to describe certain components and shall not be considered as warranted characteristics.

Terms of delivery and rights to technical change reserved.

We hereby disclaim any and all warranties, including but not limited to warranties of non-infringement, regarding circuits, descriptions and charts stated herein.

Infineon Technologies is an approved CECC manufacturer.

Information

For further information on technology, delivery terms and conditions and prices please contact your nearest Infineon Technologies Office in Germany or our Infineon Technologies Representatives worldwide (see address list).

Warnings

Due to technical requirements components may contain dangerous substances. For information on the types in question please contact your nearest Infineon Technologies Office.

Infineon Technologies Components may only be used in life-support devices or systems with the express written approval of Infineon Technologies, if a failure of such components can reasonably be expected to cause the failure of that life-support device or system, or to affect the safety or effectiveness of that device or system. Life support devices or systems are intended to be implanted in the human body, or to support and/or maintain and sustain and/or protect human life. If they fail, it is reasonable to assume that the health of the user or other persons may be endangered.

Off-Line SMPS Current Mode Controller

with integrated

650V/800V

Product Highlights

Best in class in DIP8, DIP7, TO220 packages

No heatsink required for DIP8, DIP7

Lowest standby power dissipation

Enhanced protection functions all with Auto Restart Mode

Isolated drain package for TO220

Increased creepage distance for TO220 packages

CoolSET™-F2

P-DIP-7-1

P-DIP-7-1

P-DIP-8-6

P-DIP-8-4, -6

PP--TO220O220-6-46-6-46 P-TO220-6-47

P-TO220-6-47

Features

Description

• 650V/800V avalanche rugged CoolMOS™

The second generation CoolSET™-F2 provides several

• Only few external components required

special enhancements to satisfy the needs for low power

• Input Vcc Undervoltage Lockout

standby and protection features. In standby mode

67kHz/100kHz switching frequency

frequency reduction is used to lower the power

• Max duty cycle 72%

consumption and support a stable output voltage in this

• Low Power Standby Mode to meet

mode. The frequency reduction is limited to 20kHz/21.5

 

European Commission Requirements

kHz to avoid audible noise. In case of failure modes like

• Thermal Shut Down with Auto Restart

open loop, overvoltage or overload due to short circuit the

• Overload and Open Loop Protection

device switches in Auto Restart Mode which is controlled by

• Overvoltage Protection during Auto Restart

the internal protection unit. By means of the internal precise

• Adjustable Peak Current Limitation via

peak current limitation the dimension of the transformer and

 

external resistor

the secondary diode can be lower which leads to more cost

Overall tolerance of Current Limiting < ±5%

efficiency.

Internal Leading Edge Blanking

User defined Soft Start Soft Switching for low EMI

 

 

Typical Application

 

 

 

 

 

+

 

 

RStart-up

Snubber

Converter

85 ... 270 VAC

 

DC Output

 

 

 

 

 

 

-

 

 

CVCC

Drain

 

 

 

VCC

 

 

 

 

 

Feedback

Low Power

 

Power

 

 

StandBy

Management

CoolMOS™

 

 

 

 

 

SoftS

 

PWM Controller

 

 

Soft-Start Control

 

 

Current Mode

 

 

CSoft Start

 

 

 

 

Precise Low Tolerance

 

Isense

 

 

Peak Current Limitation

 

 

FB

 

 

 

RSense

 

Protection Unit

 

 

 

 

 

GND

PWM-Controller

 

 

 

 

 

 

 

CoolSET™-F2

 

 

 

 

Feedback

 

 

 

 

Datasheet V4.5

 

3

 

Jan 2004

CoolSET™-F2

Ordering Codes

Type

Ordering Code

Package

VDS

FOSC

RDSon1)

230VAC ±15% 2)

85-265 VAC2)

ICE2A0565

Q67040-S4542

P-DIP-8-6

650V

100kHz

4.7Ω

23W

13W

ICE2A165

Q67040-S4426

P-DIP-8-6

650V

100kHz

3.0Ω

31W

18W

ICE2A265

Q67040-S4414

P-DIP-8-6

650V

100kHz

0.9Ω

52W

32W

ICE2A365

Q67040-S4415

P-DIP-8-6

650V

100kHz

0.45Ω

67W

45W

ICE2B0565

Q67040-S4540

P-DIP-8-6

650V

67kHz

4.7Ω

23W

13W

ICE2B165

Q67040-S4489

P-DIP-8-6

650V

67kHz

3.0Ω

31W

18W

ICE2B265

Q67040-S4478

P-DIP-8-6

650V

67kHz

0.9Ω

52W

32W

ICE2B365

Q67040-S4490

P-DIP-8-6

650V

67kHz

0.45Ω

67W

45W

ICE2A0565Z

Q67040-S4541

P-DIP-7-1

650V

100kHz

4.7Ω

23W

13W

ICE2A180Z

Q67040-S4546

P-DIP-7-1

800V

100kHz

3.0Ω

29W

17W

ICE2A280Z

Q67040-84547

P-DIP-7-1

800V

100KHz

0.8Ω

50W

31W

 

 

 

 

 

 

 

 

1)typ @ T=25°C

2)Maximum power rating at Ta=75°C, Tj=125°C and with copper area on PCB = 6cm²

Type

Ordering Code

Package

VDS

FOSC

RDSon1)

230VAC ±15% 2)

85-265 VAC2)

ICE2A765I

Q67040-S4609

P-TO-220-6-46

650V

100kHz

0.45Ω

240W

130W

ICE2B765I

Q67040-S4607

P-TO-220-6-46

650V

67kHz

0.45Ω

240W

130W

ICE2A765P2

Q67040-S4610

P-TO-220-6-47

650V

100kHz

0.45Ω

240W

130W

ICE2B765P2

Q67040-S4608

P-TO-220-6-47

650V

67kHz

0.45Ω

240W

130W

 

 

 

 

 

 

 

 

1)typ @ T=25°C

2)Maximum practical continuous power in an open frame design at Ta=75°C, Tj=125°C and Rth=2.7K/W

Datasheet V4.5

4

Jan 2004

CoolSET™-F2

Table of Contents

 

Page

1

Pin Configuration and Functionality . . . . . . . . . . . . . . . . . . . . . . .

. . . . . .6

 

1.1

Pin Configuration with P-DIP-8-6

. . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . .6

1.2

Pin Configuration with P-DIP-7-1

. . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . .6

1.3

Pin Configuration with P-TO220-6-46/47 . . . . . . . . . . . . . . . . . . . . . .

. . . . . .7

1.4

Pin Functionality . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . .7

 

2

Representative Blockdiagram

. . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . .8

 

3

Functional Description . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . .9

 

3.1

Power Management . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . .9

 

3.2

Improved Current Mode . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . . .9

 

3.2.1

PWM-OP . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . .10

 

3.2.2

PWM-Comparator . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . .10

3.3

Soft-Start . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . .11

 

3.4

Oscillator and Frequency Reduction . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . .12

 

3.4.1

Oscillator . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . .12

 

3.4.2

Frequency Reduction . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . .12

3.5

Current Limiting . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . . .12

3.5.1

Leading Edge Blanking . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . .12

3.5.2

Propagation Delay Compensation . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . .13

3.6

PWM-Latch . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . .13

 

3.7

Driver . . . . . . . . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . .13

3.8

Protection Unit (Auto Restart Mode) . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . .14

3.8.1

Overload / Open Loop with Normal Load . . . . . . . . . . . . . . . . . . . .

. . . .14

 

3.8.2

Overvoltage due to Open Loop with No Load . . . . . . . . . . . . . . . . .

. . . .15

 

3.8.3

Thermal Shut Down . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . .15

4

Electrical Characteristics . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . .16

 

4.1

Absolute Maximum Ratings . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . .16

 

4.2

Thermal Impedance (ICE2X765I and ICE2X765P2) . . . . . . . . . . . . . .

. . . .18

 

4.3

Operating Range . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . .18

 

4.4

Characteristics . . . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . .19

 

4.4.1

Supply Section . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . .19

4.4.2

Internal Voltage Reference . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . .20

 

4.4.3

Control Section . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . .20

 

4.4.4

Protection Unit . . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . .21

4.4.5

Current Limiting . . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . .21

4.4.6

CoolMOS™ Section . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . .22

 

5

Typical Performance Characteristics . . . . . . . . . . . . . . . . . . . . . . .

. . . .24

 

6

Layout Recommendation for C18 . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . .30

 

7

Outline Dimension . . . . . . . . . .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

. . . .31

 

 

 

 

Datasheet V4.5

5

Jan 2004

 

CoolSET™-F2

Pin Configuration and Functionality

1 Pin Configuration and Functionality

1.1

Pin Configuration with P-DIP-8-6

1.2

Pin Configuration with P-DIP-7-1

Pin

Symbol

Function

 

 

 

1

SoftS

Soft-Start

 

 

 

2

FB

Feedback

 

 

 

3

Isense

Controller Current Sense Input,

 

 

CoolMOS™ Source Output

4

Drain

650V1)/800V2) CoolMOS™ Drain

5

Drain

650V1)/800V2) CoolMOS™ Drain

6

N.C

Not connected

 

 

 

7

VCC

Controller Supply Voltage

 

 

 

8

GND

Controller Ground

 

 

 

1)at Tj = 110°C

2)at Tj = 25°C

Pin

Symbol

Function

 

 

 

1

SoftS

Soft-Start

 

 

 

2

FB

Feedback

 

 

 

3

Isense

Controller Current Sense Input,

 

 

CoolMOS™ Source Output

4

N.C.

Not connected

 

 

 

5

Drain

650V1)/800V2) CoolMOS™ Drain

7

VCC

Controller Supply Voltage

 

 

 

8

GND

Controller Ground

 

 

 

1)at Tj = 110°C

2)at Tj = 25°C

 

Package P-DIP-8-6

 

SoftS

1

8

GND

FB

2

7

VCC

Isense

3

6

N.C

 

 

Drain

4

5

Drain

 

 

 

Package P-DIP-7-1

 

SoftS

1

8

GND

FB

2

7

VCC

Isense

3

 

 

 

 

 

n.c.

4

5

Drain

 

 

Figure 1

Pin Configuration (top view)

Figure 2

Pin Configuration (top view)

Datasheet V4.5

6

Jan 2004

CoolSET™-F2

Pin Configuration and Functionality

1.3

Pin Conuration with P-TO220-6-46/47 1.4

Pin Functionality

Pin

Symbol

Function

 

 

 

 

1

Drain

650V1)

CoolMOS™ Drain

3

Isense

650V1)

CoolMOS™ Source

4

GND

Controller Ground

 

 

 

5

VCC

Controller Supply Voltage

 

 

 

6

SoftS

Soft-Start

 

 

 

7

FB

Feedback

 

 

 

 

1)at Tj = 110°C

Package P-TO220-6-46/47

1 2 3 4 5 6 7

SoftS (Soft Start & Auto Restart Control)

This pin combines the function of Soft Start in case of Start Up and Auto Restart Mode and the controlling of the Auto Restart Mode in case of an error detection.

FB (Feedback)

The information about the regulation is provided by the FB Pin to the internal Protection Unit and to the internal PWM-Comparator to control the duty cycle.

Isense (Current Sense)

The Current Sense pin senses the voltage developed on the series resistor inserted in the source of the integrated CoolMOS™. When Isense reaches the internal threshold of the Current Limit Comparator, the Driver output is disabled. By this means the Over Current Detection is realized.

Furthermore the current information is provided for the PWM-Comparator to realize the Current Mode.

Drain (Drain of integrated CoolMOS™)

Pin Drain is the connection to the Drain of the internal CoolMOSTM.

VCC (Power supply)

This pin is the positiv supply of the IC. The operating range is between 8.5V and 21V.

To provide overvoltage protection the driver gets disabled when the voltage becomes higher than 16.5V during Start Up Phase.

GND (Ground)

This pin is the ground of the primary side of the SMPS.

Drain

Isense

GND

VCC

SoftS

FB

Figure 3 Pin Configuration (top view)

Datasheet V4.5

7

Jan 2004

INFINEON ICE2A0565, ICE2A165, ICE2A265, ICE2A365, ICE2B0565 User Manual

8 5.V4 Datasheet

BlockdiagramRepresentative 4 Figure

FB

 

 

 

 

 

 

 

 

 

 

 

Current-Limit

 

 

 

10k

RSense

BlockdiagramRepresentative 2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

+

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Converter

 

 

 

 

 

RStart-up

 

 

CLine

 

 

 

 

 

 

 

 

 

Snubber

 

DC Output

 

 

 

85 ... 270 VAC

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

VOUT

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

-

 

 

 

 

 

 

 

 

 

CVCC

 

 

 

 

 

 

 

 

 

Drain

 

 

 

 

 

 

 

VCC

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Power Management

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Undervoltage

Internal Bias

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Lockout

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

C1

 

 

 

 

13.5V

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

16.5V

 

 

 

 

8.5V

 

 

 

 

 

 

Duty Cycle Max

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Power-Down

 

6.5V

Oscillator

 

0.72

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reset

 

Voltage

5.3V

 

 

 

 

 

 

 

 

 

 

 

6.5V

 

 

 

 

 

 

 

 

4.8V

Duty Cycle

 

 

 

 

 

 

 

 

 

 

 

4.0V

C2

 

 

 

 

 

 

Reference

4.0V

max

 

 

 

 

 

 

 

 

 

 

 

 

 

G1

 

 

Power-Up

 

 

 

 

 

 

 

 

 

 

 

 

 

 

RSoft-Start

 

 

 

 

Reset

 

 

 

Clock

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

fstandby-fnorm

 

 

 

 

 

 

 

 

 

 

SoftS

 

 

 

 

 

 

 

 

 

Soft Start

Soft-Start

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PWM-Latch

CoolMOS™

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Comparator

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

S

Q

 

 

 

 

 

 

 

 

 

5.6V

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CSoft-Start

 

 

C4

 

 

Spike

S

Q

 

 

 

 

R

Q

 

 

 

 

 

 

 

 

 

5.3V

 

G3

Blanking

 

 

 

 

Gate

 

 

 

 

 

 

 

 

 

G2

 

 

 

 

 

G4

 

 

 

 

 

 

 

 

T1

6.5V

 

 

 

 

5 s

 

 

 

 

 

 

 

Driver

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4.8V

C3

 

 

 

 

R

Q

 

PWM

 

 

 

 

 

 

 

 

 

 

 

 

RFB

 

 

 

 

Error-Latch

 

Comparator

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

0.3V

C5

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Thermal Shutdown

 

 

 

fosc

 

 

 

 

Comparator

 

 

Leading Edge

 

 

 

 

 

 

 

 

 

 

 

 

fnorm

 

 

 

 

 

 

 

 

Vcsth

Blanking

D1

Isense

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

220ns

 

 

 

 

 

 

Tj

>140°C

 

 

fstandby

 

UFB

0.8V

 

 

 

 

 

 

 

 

BlockdiagramRepresentative

 

2004Jan

 

 

 

Protection Unit

 

 

Standby Unit

 

 

 

 

Propagation-Delay

 

 

 

 

F2CoolSET™-

 

 

 

 

 

 

 

 

x3.65

Compensation

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PWM OP

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Improved Current Mode

Current Limiting

 

 

 

 

Optocoupler

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CoolSET™-F2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

GND

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ICE2Axxxx

ICE2Bxxxx

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

fnorm

100kHz

 

67kHz

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

fstandby

21.5kHz

 

20kHz

 

 

 

 

 

 

CoolSET™-F2

Functional Description

3 Functional Description

3.1

Power Management

3.2

Improved Current Mode

 

M ain Line (100V -380V)

 

R S tart-U p

 

 

 

Prim ary W inding

 

C VC C

V C C

 

 

Pow er Managem ent

U nd ervo ltag e

 

Intern al

 

 

L ockout

 

B ia s

1 3.5V

 

 

 

8 .5V

 

 

P o w er-D ow n

 

6.5 V

 

 

R e set

 

5.3 V

 

 

V olta ge

 

 

4.8 V

 

 

R e fe rence

P o w e r-U p

 

4.0 V

 

 

R ese t

 

 

 

R

Q

 

 

P W M -La tch

6.5V

S

Q

R S oft-S tart

E rro r-Latch

S o ftS

 

 

 

 

S oft-Start Com parator

T 1

 

E rror-D e te ctio n

C S oft-Start

 

 

Figure 5 Power Management

The Undervoltage Lockout monitors the external supply voltage VVCC. In case the IC is inactive the current consumption is max. 55µA. When the SMPS is

plugged to the main line the current through RStart-up charges the external Capacitor CVCC. When VVCC

exceeds the on-threshold VCCon=13.5V the internal bias circuit and the voltage reference are switched on. After that the internal bandgap generates a reference voltage VREF=6.5V to supply the internal circuits. To avoid uncontrolled ringing at switch-on a hysteresis is implemented which means that switch-off is only after active mode when Vcc falls below 8.5V.

In case of switch-on a Power Up Reset is done by reseting the internal error-latch in the protection unit.

When VVCC falls below the off-threshold VCCoff=8.5V the internal reference is switched off and the Power Down

reset let T1 discharging the soft-start capacitor CSoft-Start at pin SoftS. Thus it is ensured that at every switch-on

the voltage ramp at pin SoftS starts at zero.

Soft-Start C om parator

FB

PW M -Latch

 

 

 

R

Q

 

 

D river

PW M C om parator

 

 

 

S

Q

0.8V

 

 

PW M O P

 

 

x3.65

Isense

Im proved

 

 

Current M ode

 

 

Figure 6 Current Mode

Current Mode means that the duty cycle is controlled by the slope of the primary current. This is done by comparison the FB signal with the amplified current sense signal.

Amplified Current Signal

 

FB

 

0.8V

 

Driver

t

Ton

 

 

t

Figure 7 Pulse Width Modulation

In case the amplified current sense signal exceeds the FB signal the on-time Ton of the driver is finished by reseting the PWM-Latch (see Figure 7).

Datasheet V4.5

9

Jan 2004

CoolSET™-F2

The primary current is sensed by the external series resistor RSense inserted in the source of the integrated CoolMOS™. By means of Current Mode the regulation of the secondary voltage is insensitive on line variations. Line variation causes varition of the increasing current slope which controls the duty cycle. The external RSense allows an individual adjustment of the maximum source current of the integrated CoolMOS™.

Soft-Start C om parator

 

 

 

 

PW M C om parator

FB

 

 

 

 

 

 

 

PW M -Latch

O scillator

0.3V

 

 

 

C 5

 

 

 

 

G ate D river

V O S C

 

 

 

 

0.8V

 

 

 

10kΩ

 

x3.65

 

 

R 1

 

T

2

V 1

 

 

 

PW M O P

 

C 1

20pF

 

 

 

Voltage Ram p

 

 

 

Figure 8 Improved Current Mode

To improve the Current Mode during light load conditions the amplified current ramp of the PWM-OP is superimposed on a voltage ramp, which is built by the switch T2, the voltage source V1 and the 1st order low pass filter composed of R1 and C1(see Figure 8, Figure 9). Every time the oscillator shuts down for max. duty cycle limitation the switch T2 is closed by VOSC. When the oscillator triggers the Gate Driver T2 is opened so that the voltage ramp can start.

In case of light load the amplified current ramp is to small to ensure a stable regulation. In that case the Voltage Ramp is a well defined signal for the comparison with the FB-signal. The duty cycle is then controlled by the slope of the Voltage Ramp.

By means of the Comparator C5, the Gate Driver is switched-off until the voltage ramp exceeds 0.3V. It allows the duty cycle to be reduced continously till 0% by decreasing VFB below that threshold.

Functional Description

VOSC

 

max.

 

Duty Cycle

 

Voltage Ramp

t

 

0.8V

 

FB

 

0.3V

 

Gate Driver

t

 

 

t

Figure 9 Light Load Conditions

3.2.1PWM-OP

The input of the PWM-OP is applied over the internal leading edge blanking to the external sense resistor

RSense connected to pin ISense. RSense converts the source current into a sense voltage. The sense voltage

is amplified with a gain of 3.65 by PWM OP. The output of the PWM-OP is connected to the voltage source V1. The voltage ramp with the superimposed amplified current singal is fed into the positive inputs of the PWMComparator, C5 and the Soft-Start-Comparator.

3.2.2PWM-Comparator

The PWM-Comparator compares the sensed current signal of the integrated CoolMOSTM with the feedback signal VFB (see Figure 10). VFB is created by an external optocoupler or external transistor in combination with the internal pullup resistor RFB and provides the load information of the feedback circuitry. When the amplified current signal of the integrated CoolMOS™ exceeds the signal V FB the PWMComparator switches off the Gate Driver.

Datasheet V4.5

10

Jan 2004

CoolSET™-F2

 

6.5V

R FB

Soft-Start C om parator

FB

PW M -Latch

 

 

PW M C om parator

 

0.8V

O ptocoupler

PW M O P

 

 

Isense

 

x3.65

 

Im proved

 

Current M ode

Figure 10 PWM Controlling

3.3Soft-Start

V S oftS

 

5.6V

 

5.3V

 

T S oft-S tart

 

G ate D river

t

 

t

Functional Description

pullup resistor RSoft-Start. The Soft-Start-Comparator compares the voltage at pin SoftS at the negative input

with the ramp signal of the PWM-OP at the positive

input. When Soft-Start voltage VSoftS is less than Feedback voltage VFB the Soft-Start-Comparator limits

the pulse width by reseting the PWM-Latch (see Figure 11). In addition to Start-Up, Soft-Start is also activated at each restart attempt during Auto Restart. By means

of the above mentioned CSoft-Start the Soft-Start can be defined by the user. The Soft-Start is finished when

VSoftS exceeds 5.3V. At that time the Protection Unit is activated by Comparator C4 and senses the FB by

Comparator C3 wether the voltage is below 4.8V which means that the voltage on the secondary side of the SMPS is settled. The internal Zener Diode at SoftS with breaktrough voltage of 5.6V is to prevent the internal circuit from saturation (see Figure 12).

 

 

 

 

 

 

 

 

 

 

 

 

6 .5 V

 

 

 

 

 

 

 

 

5 .6V

 

 

 

 

 

 

 

 

 

 

P ow er-U p R eset

 

 

 

 

 

 

 

 

 

R S oft-S tart

 

 

 

 

E rror-Latch

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

S oftS

 

 

 

 

 

 

 

 

 

C 4

 

 

 

 

 

 

 

R

Q

 

 

 

6 .5 V

 

 

 

 

 

 

 

G 2

 

 

 

S

Q

 

 

 

 

 

 

 

 

 

5 .3V

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4 .8V

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R F B

 

 

 

 

 

C 3

 

 

 

 

 

 

 

R

Q

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

G ate

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

F B

 

 

 

 

 

 

C lock

 

 

 

S

Q

D river

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

P W M -Latch

Figure 12 Activation of Protection Unit

The Start-Up time TStart-Up within the converter output voltage VOUT is settled must be shorter than the Soft-

Start Phase TSoft-Start (see Figure 13).

CSoft Start

TSoft Start

= -------------------------------------

 

RSoft Start × 1.69

By means of Soft-Start there is an effective minimization of current and voltage stresses on the integrated CoolMOS™, the clamp circuit and the output overshoot and prevents saturation of the transformer during Start-Up.

Figure 11 Soft-Start Phase

The Soft-Start is realized by the internal pullup resistor

RSoft-Start and the external Capacitor CSoft-Start (see Figure 2). The Soft-Start voltage VSoftS is generated by charging the external capacitor CSoft-Start by the internal

Datasheet V4.5

11

Jan 2004

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