L6615

8/20

APPLICATION INFORMATION

Index

page

1.

Introduction

8

2.

Current sense section

9

3.

Share drive section, error amplifier and adjust amplifier

10

4.

Designing with L6615

10

5.

Current sense methods

13

6.

Application ideas

14

7.

Low voltage buses

15

8.

Offset Trimming

16

1

INTRODUCTION

Power supply systems are often designed by paralleling converters in order to improve performance and

reliability.

To ensure uniform distribution of stresses, the total load current should be shared appropriately among

the converters.

A typical application is showed in fig. 9 for a series of N paralleled modules (PS#1 to PS#N): each of them

exhibits 4 terminals: two for the power output (+OUT, -OUT) and two for the remote sense signals

(+OUT_S, -OUT_S).

(to avoid that the failure of one module shorts the load out)

L6615 allows attaining an automatic master-slave current sharing architecture: one L6615 is associated to each

power supply and all these IC's are linked each other through the share bus (referred to the common ground).

This kind of system configuration is preferred to the systems in which a single current sharing controller is

used because of robustness, reliability and flexibility.

To configure a load share controller, few passive components are used. A brief device explanation will

follow with the formulas useful to set these external components.

Figure 9. Typical high side connection

CS-

CGA

CS+

VCC

ADJ

SHARE

GND

COMP

3

2

4

1

5

6

7

8

L6615

+OUT

GND

PS #1

C

C

R

C

R

CGA

R

ADJ

R

SENSE

CS-

CGA

CS+

VCC

ADJ

SHARE

GND

COMP

3

2

4

1

5

6

7

8

L6615

+OUT

+OUT_S

-OUT_S

-OUT

PS #N

C

C

R

C

R

CGA

R

ADJ

R

SENSE

+OUT

+OUT_S

-OUT_S

-OUT

R

G1

R

G2

R

G1

R

G2

SHARE BUS

LOAD

CS-

CGA

CS+

VCC

ADJ

SHARE

GND

COMP

3

2

4

1

5

6

7

8

L6615

+OUT

GND

PS #1

C

C

R

C

R

CGA

R

ADJ

R

SENSE

CS-

CGA

CS+

VCC

ADJ

SHARE

GND

COMP

3

2

4

1

5

6

7

8

L6615

+OUT

+OUT_S

-OUT_S

-OUT

PS #N

C

C

R

C

R

CGA

R

ADJ

R

SENSE

+OUT

+OUT_S

-OUT_S

-OUT

R

G1

R

G2

R

G1

R

G2

SHARE BUS

LOAD