uba2015t/n1 NXP Semiconductors, uba2015t/n1 Datasheet - Page 16

• 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
Fig 12. Lamp current control
I
BOOST
I
lamp
R ext(IFB)
BOOST
DIM
IFB
grey circuit parts are not present in some types
VDD
R i(IFB)
I bias(DIM)
The output of the OTA is connected to pin CIFB. The external capacitor C
charged and discharged according to the voltage on the OTA inputs and the
transconductance of the OTA, g
I
More components can be connected to pin CIFB to improve the response time and
stability of the lamp current control loop.
Pin CIFB is connected to the input of the VCO (Voltage Controlled Oscillator) that
determines the frequency of the IC. Pin CIFB voltage is inversely proportional to the
switching frequency. When the load is inductive, an increase in frequency decreases the
lamp current, and a decrease in frequency increases the lamp current. With the closed
loop for the lamp current in place, the IC will regulate to the required frequency for the
desired lamp current. So when the IC enters Burn state it will go to either point D or H
shown in
voltage.
CIFB
DOUBLE SIDE
RECTIFIER
= g
V reg(ref)
m(IFB)
1
Figure 10
1
1
VDD
× (V
3.5
7.8
All information provided in this document is subject to legal disclaimers.
VDD
IFB
(UBA2015A) or
− V
Rev. 1 — 20 May 2011
reg(IFB
).
m(IFB)
VOLTAGE
CONTROLLED
OSCILLATOR
VDD
Figure 11
according to the formula:
I ch(low)(CF)
CF
C ext(CF)
(UBA2016A) depending on the DIM input
OTA
g m(IFB)
UBA2016A/15/15A
VDD
VOLTAGE
CONTROLLED
CURRENT SOURCE
÷ 2
600 V fluorescent lamp driver
V high(CF)
clock
001aan205
© NXP B.V. 2011. All rights reserved.
ext(CIFB)
CIFB
C ext(CIFB)
is
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