2001 Jan 30

11

Philips Semiconductors

Product specification

630 V driver IC for CFL and TL lamps

UBA2021

DESIGN EQUATIONS

• Bottom frequency:

• Feed-forward frequency:

Where:

– X1 = 3.68

– X2 = 22.28

–

τ = 0.4 µs

Where:

• Preheat time:

• Ignition time:

• Non-overlap time:

f

B

1

2C

CF

C

par

+

()

X1

R

RREF

×

R

int

–

()

×

[] τ

+

{}

×

---------------------------------------------------------------------------------------------------------------------------

=

f

ff

1

2C

CF

C

par

+

()

X2

V

RREF

×

I

iRHV

()

-------------------------------

R

int

–





×τ

+







×

----------------------------------------------------------------------------------------------------------------------------

=

t

ph

C

CP

150 nF

------------------

R

RREF

30 k

Ω

-----------------

×

=

t

ign

15

16

------

t

ph

×

=

t

no

1.4

µs

R

RREF

30k

Ω

-----------------

×

=