UBA2071AT/N1,118 NXP Semiconductors, UBA2071AT/N1,118 Datasheet - Page 12

• 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
Advantage of the sweep rather than a fixed ignition frequency is that sensitivity for spread
in resonance frequency is much lower.
Once the lamps are ignited the frequency sweep-down continues, gradually increasing the
lamp current (the resonance circuit should now still be inductive, so current increases as
frequency drops) until the current regulation level is reached (at f
will not reach f
that the lamps are on (if the average absolute voltage at the current feedback input (pin
IFB) is above V
The initial ignition frequency sweep and the PWM generator are not synchronized. Once
the regulation frequency is reached, PWM dimming can start anywhere in its cycle. A
small internal PWM dimming enable delay time, t
before PWM dimming starts.
At the start of the lamps-off period of the PWM dimming, the switching frequency is swept
up to f
both GL and GH are made low, so both half bridge powers will be non-conducting. This is
indicated by the dotted part of the switching frequency (f
Fig 8.
(1) Indicates lamp-OFF.
(2) Indicates lamp-ON.
sw(max)
Initial ignition of cold cathode fluorescent lamp via frequency sweep and load
resonance
. This reduces the lamp voltage so the lamps go out. If f
sw(min)
th(lod)(IFB)
if the lamp current comes into regulation. Once it has been detected
V
V
V
(V)
lamp
Rev. 01 — 23 June 2008
ign
burn
) PWM dimming is enabled. See
f
sw(min)
(2)
f
reg
Half bridge control IC for CCFL backlighting
UBA2071; UBA2071A
(1)
f
ign
d(en)PWM
f (kHz)
sw
Figure
, allows the lamps to settle
) line in
014aaa103
f
sw(max)
9.
sw
Figure
= f
sw(max)
reg
© NXP B.V. 2008. All rights reserved.
). The frequency
9.
is reached,
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