uba20261 NXP Semiconductors, uba20261 Datasheet - Page 8

• Manufacturer Part Number: uba20261
• Description: 600 V And 350 V Power Ic For Step Dimmable Cfls
• Manufacturer: NXP Semiconductors

NXP Semiconductors
UBA20261_UBA20262
Preliminary data sheet
Fig 5.
Retry cycle
V
V
th(CP)max
V
th(CP)min
th(rel)CP
7.1.5 Boost state and transition to burn state
5 V
0 V
voltage
(V)
startup
time
When ignition is detected, by measuring lamp current on the CSI pin, the circuit enters the
boost state.
nominal burn state lamp current can be increased with a fixed boost ratio of 1.5 : 1. This
ratio boosts the slow luminescence increase of a cold amalgam CFL lamp, provided the
IC is in the DIM_1 mode. If the IC is at a temperature (T
state, the burn state is bypassed.
A boost timing circuit is included to determine the boost time and transition to burn time.
The circuit consists of a clock generator comprising C
When the timer is not operating, C
voltage, approximately 0.6 V, is still higher than the level at which the comparator on C
detects if the CB pin is shorted to ground.
The boost time consists of 63 saw-tooth pulses on the CB pin, automatically followed by
the transition time at the CP pin. The 32 saw-tooth pulses form the transition time from
boost to burn and enables a smooth transition between the current controlled boost and
burn state. The total transition time is approximately four times the preheat time (see
Figure
1
st
preheat
time
t
ph
6).
V
CP
enabling time
1
st
t
en(ign)
Figure 7
ignition
All information provided in this document is subject to legal disclaimers.
1
ignition
attempt
st
shows the boost and burn state in more detail. In the boost state, the
Rev. 1 — 9 September 2011
failed
HOLD STATE
delay time
t
d(restart)
restart
CB
600 V and 350 V power IC for step dimmable CFLs
startup
is discharged below the V
2
nd
2
nd
time
preheat
t
ph
enabling time
2
nd
t
en(ign)
ignition
CB
, R
j(bp)bst
POWER DOWN STATE
ext(RREF)
2
ignition
attempt
nd
failed
) before entering the boost
th(CB)min
UBA20261/2
and a 64-step counter.
level of 1.1 V. This
© NXP B.V. 2011. All rights reserved.
discharge
001aan537
to 0 V
time (s)
8 of 32
CB