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| 美芯MAX17019高压电源控制方案 |
| 作者： 时间：2008-09-04 来源:eaw |
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美芯(Maxim)公司的MAX17019是高输入电压(高达38V)四输出控制器,提供四个单独稳压器的紧凑低成本控制方案.四个输出包括主级稳压器,3A降压稳压器,5A降压稳压器和2A线性稳压器.输入电压高达38V使MAX17019可用在汽车电子中,嵌入控制系统和机顶盒.本文介绍了MAX17019的主要特性和方框图以及标准的应用电路图.
The MAX17019 is a high-input-voltage quad-output controller (up to 38V). The MAX17019 provides a compact, low-cost controller capable of providing four independent regulators—a main stage, a 3AP-P internal stepdown, a 5AP-P internal step-down, and a 2A source/sink linear regulator. The input voltage is up to 38V. This makes it an excellent choice for automotive applications.
The internal switching regulators include 5V synchronous MOSFETs that can be powered directly from a single Li+ cell or from the main 3.3V/5V power stages. Finally, the linear regulator is capable of sourcing and sinking 2A to support DDR termination requirements or to generate a fixed output voltage.
The step-down converters use a peak current-mode, fixed-frequency control scheme—an easy to implement architecture that does not sacrifice fast-transient response. This architecture also supports peak currentlimit protection and pulse-skipping operation to maintain high efficiency under light-load conditions.
Separate enable inputs and independent open-drain power-good outputs allow flexible power sequencing. A soft-start function gradually ramps up the output voltage to reduce the inrush current. Disabled regulators enter high-impedance states to avoid negative output voltage created by rapidly discharging the output through the low-side MOSFET. The MAX17019 also includes output undervoltage, output overvoltage, and
thermal-fault protection.
The MAX17019 is available in a 48-pin, 6mm x 6mm thin QFN package.
MAX17019主要特性:
Fixed-Frequency, Current-Mode Controllers
5.5V to 38V Input Range (Step-Down)
1x Step-Down Controller
1x Internal 5AP-P Step-Down Regulator
1x Internal 3AP-P Step-Down Regulator
1x 2A Source/Sink Linear Regulator with Dynamic REFIN
Internal BST Diodes
Internal 5V 50mA Linear Regulator
Fault Protection—Undervoltage, Overvoltage, Thermal, Peak Current Limit
Independent Enable Inputs and Power-Good Outputs
Voltage-Controlled Soft-Start
High-Impedance Shutdown
10μA (typ) Shutdown Current
应用:
Automotive Battery-Powered Devices
Embedded Control Systems
Set-Top Boxes
图1.MAX17019方框图
图2. MAX17019标准应用电路图
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