Transcript Document 7744227
LED BLU Driving and Challenge
Q4, 2010
Allen Zhang On-Bright confidential
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Outline
1. LED to CCFL Replacement
LED backlight benefits analysis CCFL/LED market share trend
2. Small & Middle Size Driving Topology
LED notebook/Netbook LED monitor Low-end display
3. LED TV Driving Topology 4. OB LED Driver Roadmap
5. Q&A 2
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Internet Connectivity TV Products Innovations 3D Display Human Interface TV Products Innovations LED Backlight
LED backlight is very hot On-Bright confidential
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LED Type
Current Capability
Standard LED - drive current <50mA
High current LED - drive current 50-150mA
High power LED - drive current 150-1000mA+ Color
White LEDs
Red, Green and Blue LEDs (Combined white) Forward voltage depends on color
Red ~2V, Green ~3.5V, Blue/White ~3.5-4V
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Benefits of LED Backlight
Power saving (30~40% saving for 12~14” NB)
Longer life time (+50,000 hrs vs. ~20,000hrs of CCFL)
0~100% wide dimming range (up to 20KHz PWM dimming, audio noise free)
Low voltage driver reduces complexity power design
Environmental friendly (CCFL contains Hg)
Local dimming for power saving and higher CR (Large size direct type backlight only)
Wide color gamut (NTSC, CCFL ~78%, WLED ~80%, RGB LED >110%)
Light weight and thin profile
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Power Saving of LED BLU
Low drive voltage to ensure safety operation
The relationship between LED intensity and drive current is liner
Lower current is operated to perform the same brightness level that CCFL module
Power saving of 30~50% of CCFL power consumption
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Local Dimming of TV LED BLU
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Wide Color Gamut
• • •
NTSC cover CCFL ~78%, WLED ~80%, RGB LED >110%)
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High
Application
NB PC Low LCD TV LCD MNT
LED BLU Market Potential
Advantage Challenge • • • • Power Saving Light weight Thin profile Small cost premium • None • • Power Saving Dynamic BLU control • • • • Cost Reliability Huge LED Amount Thermal compensation • • Power Saving Thin profile • • Cost Input/output interface
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LED BLU Market Share
100.00% 80.00% 60.00% 40.00% 20.00% 0.00% 2008
2008
2009
2009
2010
2010
2011
2011 Share Rate (NB) Share Rate (MNT) Share Rate (TV)
21.90% 0.30% 0.30% 66.70% 1.90% 2.68% 89.40% 18.90% 21.26% 95.20% 35.10%
45.29%
Samsung MP LED TV at 2009, Q2
Kick off LED TV market
Low cost Edge type become main stream
Help to rise the share rate from CCFL
Power saving features
Easy to meet EPA5.0
Will break 50% share ~2012 Source: Display Search On-Bright confidential
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VIN DIM END GND
OB3360
6 X 10 LED 20mA
LED Driving Topology-NB
15” panel for example
6 strings, 10 LED per string @ 20mA Vout ~33V, Pout ~4W
OB3360 Features
Build-in 60V MOSFET 8 string output With 60mA current capability per string 160K/320K/620K/1.2MHz frequency 0~100% wide range dimming 3% channel to channel current matching
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VIN DIM END GND
OB3362
12 X 15 LED 20mA
LED Driving Topology-MNT
24” panel for example (1)
12 strings, 15 LED per string @ 20mA Vout ~50V, Pout ~12W 12CH 2 X 15 LED 100mA
24” panel for example (2)
12 strings, 15 LED per string @ 20mA Vout ~33V, Pout ~4W
parallel connection to support larger current application OB3362 Features
12 string output With 60mA current capability per string 150~500kHz frequency 0~100% wide range dimming 3% channel to channel current matching
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LED Driving Topology-Low End Display
VIN VDD DIM GND
OB3372 26” panel for example (2)
Single string, 400mA Vout ~40V, Pout ~16W All strings parallel connection 13
OB337X
0.2V reference benefits efficiency Internal burst and external PWM dimming Output over voltage protection
OB3372
:Boost,DIP8, built in 60V MOSFET
OB3370N
:Boost, SOP8, Controller
OB3370P
:Buck, SOP8, Controller
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LED vs. CCFL Cost Comparison
Q3, 2010
32" 40" 46" 55" 0 CCFL LED 22 28 ｝
premium 28%
38 54 ｝
premium 41%
41 66 ｝
premium 61%
66 95 ｝
premium 43%
50 100 150
$USD On-Bright confidential
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70% 60% 50% 40% 30% 20% 10% 0% 34% 60% Samsung 20% 45% LG 18%
LED TV Market Share Growth
2010 2011 62% 50% 50% 40% 40% 30% 20% Sony Toshiba Sharp Vizio
Source: Display Search On-Bright confidential
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LED Backlight for Large Size TV Panel
Direct Backlight: Better emission Allowing independently dimming block by block High Performance Edge Backlight: Allowing slim design Fewer LED number and lower cost Slim Profile Direct type with Local dimming Direct type without Local dimming Edge type backlight RGB LED / White LED White LED
RGB & Local dimming has power saving and high-CR feature
High-end use
Edge type solution has low cost feature
Main stream On-Bright confidential
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Direct type Edge type
LED TV Cost Down Trend
Advanced edge type Advanced edge type 40 inch LED TV
structure #LED 2008 Direct type 960 2009 Edge type 576 2010 Edge type 400 2011 Edge type 176
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LED TV Driving Topology
100V VDD 150mA
42” panel for example
4 strings 150mA per string Vout ~150V, Pout ~90W
OB3376
Dual channel boost controller 150/300kHz switching frequency Multi chip sync.
Cost effective DIM END GND 100V SYNC
OB3376
FB1 FB2 100V SYNC VDD DIM END GND 100V
OB3376
FB1 FB2 18
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PFC PFC
LED TV Power Optimize
Standby Power Digital & Audio LLC LLC DC/DC Reduced DC/DC Booster LED Balance •
Reduce DC/DC Booster
（
Cost
） •
Efficiency improvement
LED Balance Flyback Digital & Audio Standby 19
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AC input
On-Bright LED TV Total Solution
TM PFC OB6563 CCM PFC OB6573 QR Flyback OB2203 LLC Controller Coming Soon Flyback Controller OB2273 Lower Standby 20 LED Driver OB3368 (Q1, 2011) 24V@2A for audio 5V@3A for system 5V@1A for standby
Headroom voltage feedback for efficiency and thermal improvement On-Bright confidential
作者简介： 张昌山先生毕业于西南交通大学 电子工程系，长期以来一直致力于背光 驱动市场的产品规划及技术研究，张先 生于
2005
年正式加入昂宝电子（上海） 有限公司，期间一直担任系统部总监， 全权负责公司电管理芯片之应用团队及 管理。 张昌山先生在相关领域拥有丰富 的实际应用经验，在
LED
照明驱动、背 光驱动均有自己独到的见解，张先生在 该领域还拥有多项国内外专利。
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