26V、ステップアップDC-DC、84%効率で最大6個の白色LEDを駆動
SUNNYVALE, CA-March 6, 2003-Maxim Integrated Products
(NASDAQ: MXIM) introduces the MAX1561 26V, step-up DC-DC converter, which powers up to 6 white LEDs with up to 84% efficiency. Packaged in a thin QFN, this device features an internal, high-power, 30V MOSFET switch that supports 2 to 6 LEDs in series (or up to 12 in multiple chains). The MAX1561 features a constant 1MHz PWM-switching frequency and its low-profile inductor and capacitor ease filtering and data synchronization, reducing noise interference.
Unlike typical step-up converters, the MAX1561 features overvoltage and current-limit protection in case of LED disconnect, providing the most reliable, fail-proof solution available. The current regulation delivers perfect LED-to-LED current matching and brightness control, making this device ideal for cell phones, PDAs, and digital still cameras.
Competitors' products require two resistors and a capacitor to adjust brightness, but the MAX1561 offers flexible dimming control with an analog or digital PWM input without additional components. The low 15mVP-P input ripple makes this device ideal for noise-sensitive applications. Other features include internal soft-start to reduce in-rush current and 0.3mA shutdown current to maximize battery life.
The MAX1561 is packaged in an 8-pin, 3mm x 3mm thin QFN and is screened for the extended-industrial temperature range (-40°C to +85°C). Prices start at $1.30 (1000-up, FOB USA). An evaluation kit is available to speed designs.
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