UBA2071AT/N1,118 NXP Semiconductors, UBA2071AT/N1,118 Datasheet - Page 13

• Manufacturer Part Number: UBA2071AT/N1,118
• Description: IC DVR HALF BRIDGE 24-SOIC
• Manufacturer: NXP Semiconductors
• Type: CCFL/EEFL Controllerr

Specifications of UBA2071AT/N1,118

• Package / Case: 24-SOIC (7.5mm Width)
• Frequency: 38 ~ 42kHz
• Current - Supply: 1.5mA
• Voltage - Supply: 14V
• Operating Temperature: -25°C ~ 100°C
• Driver Type: CCFL Drivers
• Maximum Operating Temperature: + 100 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 25 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Output: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 935285776118

NXP Semiconductors
UBA2071_A_1
Product data sheet
8.9 Overvoltage control
The lamps start switching again on period GL and GH and the frequency is swept back to
the regulation frequency f
proportional to the capacitor connected to the CSWP pin.
The overvoltage control circuit is intended to prevent the transformer output voltage from
exceeding its maximum rating. It can also be used to regulate the output voltage to the
required lamp ignition voltage.
Under normal circumstances the capacitor at the CVFB pin is charged by a constant bias
current I
switching frequency. If the IC is in current regulation this bias current will flow away via a
tracking circuit which makes the voltage on the CVFB pin following the voltage on the
CIFB pin, see
Fig 9.
ch(CVFB)
Initial ignition frequency sweep and PWM dimming frequency sweep signals
V
V
V
V
PWMD
I
V
CSWP
CVFB
lamp
f
CIFB
sw
sec
Figure
, thus the voltage on the CVFB pin will increase resulting in a decrease of
nom
max
max
min
f
f
reg
ign
ov
0
0
0
0
0
11.
ignition
sweep
Rev. 01 — 23 June 2008
initial
reg
ignition
. The duration of the PWM frequency sweep is inverse
PWM-enable delay
steady-state
Half bridge control IC for CCFL backlighting
V
V
UBA2071; UBA2071A
CVFB
CIFB
V
CSWP
014aaa104
© NXP B.V. 2008. All rights reserved.
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t
t
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