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| Intersil汽车级TFT-LCD电源方案 |
| 作者： 时间：2008-07-23 来源:eaw |
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Intersil公司的ISL78020和ISL78022是高性能汽车级TFT-LCD升压电源解决方案，它具有2个用于 VON 和VOFF的LDO控制器，一个有可调延时的VON边电路以及用于VCOM 和 VGAMMA的放大器，输出电压精度1%，效率大于90%，同时还集成了18V/3A 的FET，特别适合用在汽车电子的TFT-LCD显示器升压电源。本文介绍了ISL78020和ISL78022的主要性能，方框图，升压控制器方框图以及典型应用电路。
Intersil Automotive Grade TFT-LCD DC/DC with Integrated Amplifiers
The ISL78020 and ISL78022 integrate a high performance boost regulator with 2 LDO controllers for VON and VOFF, a VON-slice circuit with adjustable delay and either one
(ISL78020) or five (ISL78022) amplifiers for VCOM and VGAMMA applications.
The boost converter in the ISL78020 and ISL78022 is a current mode PWM type integrating an 18V N-Channel MOSFET. Operating at 1.2MHz, this boost converter can
operate in either P-Mode for superior transient response, or in PI-Mode for tighter output regulation.
Using external low-cost transistors, the LDO controllers provide tight regulation for VON, VOFF, as well as providing start-up sequence control and fault protection.
The amplifiers are ideal for VCOM and VGAMMA applications, with 150mA peak output current drive, 12MHz bandwidth, and 12V/μs slew rate. All inputs and outputs are rail-to-rail.
Available in a 32 Ld TQFP (7mmx7mm) Pb-free package, the ISL78020, ISL78022 are specified for operation over a -40°C to +105°C temperature range.
主要特性：
Current mode boost regulator
Fast transient response
1% accurate output voltage
18V/3A integrated FET
>90% efficiency
2.6V to 5.5V VIN supply
2 LDO controllers for VON and VOFF
2% output regulation
VON-slice circuit
High speed amplifiers
150mA short-circuit output current
12V/μs slew rate
12MHz -3dB bandwidth
Rail-to-rail inputs and outputs
Built-in power sequencing
Internal soft-start
Multiple overload protection
Thermal shutdown
32 Ld 7x7 TQFP package
Pb-free (RoHS compliant)
应用：
All automotive TFT-LCD panels
图1.ISL78020, ISL78022方框图
图2. ISL78020, ISL78022升压控制器方框图
图3.典型应用电路图
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