uba2015t/n1 NXP Semiconductors, uba2015t/n1 Datasheet - Page 15

• 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
7.4.7.1 Lamp current control and dimming
The AC lamp current is sensed by an external resistor connected to pin IFB. The resulting
AC voltage on pin IFB is internally Double-Side Rectified (DSR), and compared to a
reference level by an OTA. This reference level is determined by the internal reference
regulation level V
only), as shown in
Definition: the regulation voltage on pin IFB (V
to which the IC will try to regulate the average absolute voltage on pin IFB.
If the DIM input is not present or not connected or V
V
from OTA and DSR.
For the UBA2016A V
The boost current is multiplied and added to the OTA output current which translates to an
extra voltage being added to V
the boost function. For the remainder of this Section we will assume I
For the UBA2015A and UBA2016A the DIM input controls the lamp current set point. The
DIM input level is internally clamped to V
by the bias current on pin DIM I
dimming is required, pin DIM can be left open or connected via a capacitor to ground. The
internal current source I
V
reg(ref)
reg(ref)
.
+ non-idealities from the OTA and the DSR else V
All information provided in this document is subject to legal disclaimers.
reg(ref)
Figure 12 “Lamp current
reg(IFB)
and the voltage on the DIM input (UBA2015A and UBA2016A
bias(DIM)
Rev. 1 — 20 May 2011
also depends on the input current on pin BOOST (I
reg(ref)
bias(DIM)
will then charge the pin until it is internally clamped to
. See
and the external resistance on the pin. If no
reg(ref)
Section 7.4.7.3 “Boost”
control”.
reg(IFB)
. The lowest possible DIM input level is set
UBA2016A/15/15A
DIM
) is the level seen from outside the IC
> V
reg(IFB)
600 V fluorescent lamp driver
reg(ref)
= V
then V
for further detail about
DIM
BOOST
© NXP B.V. 2011. All rights reserved.
+ non-idealities
reg(IFB)
= 0.
is
BOOST
15 of 42
).