UBA2021 NXP Semiconductors, UBA2021 Datasheet - Page 11

• Manufacturer Part Number: UBA2021
• Description: 630 V Driver Ic For Cfl And Tl Lamps
• Manufacturer: NXP Semiconductors

Philips Semiconductors
DESIGN EQUATIONS
2002 Aug 02
Bottom frequency:
Feed-forward frequency:
Where:
– X1 = 3.68
– X2 = 22.28
–
– R
– C
Operating frequency is the maximum of f
Where:
– f
– f
– f
Preheat time:
Ignition time:
Non-overlap time:
630 V driver IC for CFL and TL lamps
B
ff
cm
= 0.4 s
int
par
= feed-forward frequency
= bottom frequency
= frequency due to capacitive mode detection
= 3 k
= 4.7 pF
t
t
ign
ph
=
=
t
f
no
B
15
----- -
16
----------------- -
150 nF
C
=
=
CP
-------------------------------------------------------------------------------------------------------------------------- -
2
1.4 s
t
f
ph
ff
=
R
-----------------
30 k
--------------------------------------------------------------------------------------------------------------------------- -
2
C
RREF
CF
R
-----------------
30k
RREF
+
C
C
CF
par
B
, f
+
ff
C
or f
par
X1 R
1
cm
X2 V
------------------------------ - R
RREF
1
I
11
i RHV
–
RREF
R
int
–
+
int
+
Product specification
UBA2021