UBA2016A_15_15A All information provided in this document is subject to legal disclaimers. © NXP B.V. 2011. All rights reserved.
Product data sheet Rev. 3 — 16 November 2011 6 of 42
NXP Semiconductors
UBA2016A/15/15A
600 V fluorescent lamp driver
7. Functional description
7.1 Introduction
The UBA2016A/15/15A is an integrated circuit for electronically ballasted fluorescent
lamps. It provides a critical conduction mode Power Factor Correction (PFC)
controller/driver and a half-bridge controller/driver with all the necessary functions for
correct preheat, ignition and on-state operation of the lamp. Several protection
mechanisms are incorporated to ensure the safe operation of the fluorescent lamp or a
shut down of the complete ballast under any abnormal operating conditions or lamp
failure.
7.2 Power Factor Correction (PFC)
The PFC is a boundary conduction mode, on-time controlled system. The basic
application diagram can be found in Figure 6
. This type of PFC operates at the boundary
between continuous and discontinuous mode. Energy is stored in the inductor L
PFC
each
period that switch Q
PFC
is on. When the input current I
i(PFC)
is zero at the moment that
Q
PFC
is switched on, the amplitude of the current build up in L
PFC
will be proportional to
V
i(PFC)
and the time t
on(PFC)
that Q
PFC
is on. This current continues to flow as output
current I
o(PFC)
via D
PFC
into C
BUS
after Q
PFC
is switched off. In this phase I
o(PFC)
is equal to
I
i(PFC)
. A new cycle is started when I
o(PFC)
reaches zero. I
i(PFC)
consists of a sequence of
triangular pulses, each having an amplitude proportional to the input voltage and t
on(PFC)
.
If t
on(PFC)
is kept constant, the first harmonic of the input current is proportional to the input
voltage. The PFC output voltage V
o(PFC)
is controlled by t
on(PFC)
. As t
on(PFC)
is more slowly
regulated than the mains frequency it will not disturb the power factor.
BOOST 10 boost function input UBA2016A
PH/EN 10 preheat frequency setting combined with enable UBA2015 and UBA2015A
FBPFC 11 PFC feedback input
COMPPFC 12 PFC output voltage feedback compensation
AUXPFC 13 PFC auxiliary winding input
GPFC 14 PFC gate driver output
GND 15 ground
VDD 16 supply
GLHB 17 HB low-side switch gate driver output
SHHB 18 HB high-side source connection
FSHB 19 HB floating supply connection
GHHB 20 HB high-side switch gate driver output
Table 3. Pin description
…continued
Symbol Pin Description
