Datasheet

UBA20260 All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved.
Product data sheet Rev. 2 — 10 October 2011 5 of 30
NXP Semiconductors
UBA20260
600 V driver IC for step dimmable CFLs
7. Functional description
7.1 Supply voltage
The UBA20260 is an IC for driving external half-bridge MOSFETs in self-ballasted
high-power CFLs. The UBA20260 has no dimming control input but instead, four preset
fixed dimming levels. Only minor adjustment of the presets is possible.
The UBA20260 is rated for a maximum continuous rectified mains voltage of 500 V (with
peak 600 V). The UBA20260 includes all functions necessary for preheat, ignition and
boost operation of the lamp. In addition, the IC includes the four-step dimming feature and
several protective features to safeguard CFL operation. The controller states are shown in
Figure 3
.
(1) V
DD
< V
DD(start)
and (HOLD = 0 OR V
CP
< V
th(rel)CP
).
(2) V
DD
< V
DD(stop)
.
(3) (End of ignition time AND HOLD = 0) OR V
DD
<V
DD(stop)
.
(4) End of ignition time AND HOLD = 1
(5) V
CP
< V
th(pd)CP
, OR overcurrent fault time >
1
⁄
10
t
ph
OR f
bridge(max)
detected in capacitive mode.
Fig 3. State diagram
001aam763
V
DD
= 0
RESET STATE
HOLD = 0
START-UP STATE
PREHEAT STATE
IGNITION STATE
HOLD STATE
HOLD = 1
POWER-DOWN STATE
BOOST AND BURN
STATES
preheat time
completed
Ignition_Detected
V
DD
< V
DD(stop)
(1)
(3)
(2)
(4)
(5)
V
DD
> V
DD(rst)
V
DD
< V
DD(rst)
V
DD
< V
DD(rst)
V
CP
< V
th(rel)CP