uba2015t/n1 NXP Semiconductors, uba2015t/n1 Datasheet - Page 17

• Manufacturer Part Number: uba2015t/n1
• Description: 600 V Fluorescent Lamp Driver With Pfc, Linear Dimming And Boost Function
• Manufacturer: NXP Semiconductors

NXP Semiconductors
UBA2016A_15_15A
Objective data sheet
7.4.7.2 Operation without lamp current control
7.4.7.3 Boost
However, the switching frequency can never go below f
the boost function is active, see
f
To operate the lamp without current control the lamp current sense pin IFB must be
connected to ground. The lamp now operates at the lowest frequency f
Figure 10
The boost feature is available only in the UBA2016A to support shorter run up times. The
boost function changes the half-bridge switching frequency by lowering the lowest
possible switching frequency from f
point V
translates to an extra voltage being added to V
lowered, and as a consequence of the inductive load the lamp current is increased.
The implementation of the boost function is shown in
The boost input is a current input with an input range of 0 to I
is internally clamped at I
effect will not become bigger. The voltage on the pin is determined by the voltage drop
across the internal current mirror input and limited by an internal clamp circuit if the input
current at the pin rises above I
Table
The boost current is determined by resistor R
the boost function and with capacitor C
level (0 V) during normal lamp operation (after the boost period). The boost time constant
is reflected by the sum of capacitors C
capacitor C
An example of component values for V
R
R
sw(low)
Fig 13. Boost application example; UBA2016A
hv
BOOST
= 22 MΩ (500 V); C
4. An example of how boost function can be implemented is shown in
the IC will stay at f
reg(IFB)
= 10 MΩ and R
or
BOOST
Figure
V
by adding a multiple of the boost current to the OTA output current which
o(PFC)
All information provided in this document is subject to legal disclaimers.
C BUS
filter out the ripple on V
11). Dimming is not supported in this case.
bias
hv
R hv
Rev. 1 — 20 May 2011
sat(BOOST)
sw(low)
= 100 nF (500 V); D
= 10 MΩ.
sat(BOOST)
(point E in
Section
. If the input current at the pin is above I
sw(low)
C hv
D reset
hv
BOOST
o(PFC)
. For maximum current allowed into the pin; see
7.4.7.3). If the regulation level is not reached at
and C
to f
o(PFC)
Figure 10
sw(bst)(low)
= 430 V is:
keeps the BOOST pin at a defined (inactive)
BOOST
reset
C boost
reg(ref)
BOOST
.
R BOOST
UBA2016A/15/15A
= 1N4148; C
. R
. During boost time, the frequency is
and
Figure 12 “Lamp current
and R
and increasing the lamp current set
bias
sw(low)
R bias
BOOST
Figure
600 V fluorescent lamp driver
provides a small threshold for
BOOST
(unless for UBA2016A when
sat(BOOST)
BOOST
11).
UBA2016A
. Resistor R
001aam539
= 150 nF (63 V);
. The input current
sw(low)
© NXP B.V. 2011. All rights reserved.
sat(BOOST)
Figure
(point E in
hv
control”.
and
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13.
the