Philips Semiconductors
630 V driver IC for CFL and TL lamps
DESIGN EQUATIONS
• Bottom frequency: fB = -2----×-----{---[---(--C-----C----F----+-----C----p---a---r--)---×-----(---X--1--1-----×-----R----R----R----E---F----–-----R----i--n---t-)---]---+-----τ---}-
•
Feed-forward frequency:
fff
=
-------------------------------------------------------------1--------------------------------------------------------------
2
×
(CCF
+
Cpar)
×
X-----2---I--i×-(--R--V-H---R-V---R)---E---F--
–
Ri
n t
+
τ
Where:
– X1 = 3.68
– X2 = 22.28
– τ = 0.4 µs
– Rint = 3 kΩ
– Cpar = 4.7 pF
• Operating frequency is the maximum of fB, fff or fcm
Where:
– fB = bottom frequency
– fff = feed-forward frequency
– fcm = frequency due to capacitive mode detection
• Preheat time: tph = 1----5C---0--C---nP----F-- × R-3----0R----R-k--E-Ω---F-
• Ignition time: tign = 11----56-- × tph
• Non-overlap time: tno = 1.4 µs × -R-3---R0----Rk---EΩ----F-
Product specification
UBA2021
2002 Aug 02
11