www.SiliconStandard.com

6 of 10

SS6563

PIN DESCRIPTIONS

PIN 1: DC

- The collector of the switch - 2A.

PIN 2: DE

- Darlington switch emitter.

PIN 3: CF

- Oscillator timing capacitor.

PIN 4: GND - Power ground.

PIN 5: FB

- Feedback comparator inverting input.

PIN 6: VCC - Power supply input.

PIN 7: IS

- Highside current sense input.

PIN 8: BOOST - Bootstrapped driver collector.

APPLICATION INFORMATION

DESIGN FORMULA TABLE

CALCULATION

STEP-DOWN

STEP-UP

t

t

ON

OFF

V

+ V

V

- V

- V

OUT

F

IN(MIN)

SAT

OUT

V

+ V

V

V

- V

OUT

F

IN(MIN)

IN(MIN)

SAT

-

1

1

4x10

ON

4 x 10

ON

)

t

+ t

t

ON

OFF

OFF

RS

L(MIN)

(

)

V

- V

- V

I

t

IN(MIN)

SAT

OUT

C(SWITCH)

ON(MAX)

(

)

V

- V

I

t

IN(MIN)

SAT

C(SWITCH)

ON(MAX)

Co

I

(t

+ t

8 V

C ( SWITCH)

ON

OFF

RIPPLE( P - P )

)

I

t

V

OUT

ON

RIPPLE(P - P)

= Forward voltage of the ringback rectifier

The following power supply characteristics must be

chosen:

In practice, the calculated value will need

to be increased due to the capacitor

equivalent series resistance and board lay-

out. The ripple voltage should be kept to a

low value since it will directly affect the line

and load regulation.

Rev.2.02 4/06/2004