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Allegromicro公司的A4933是和外接功率MOSFET一起使用的三相馬達控制器.當電池電壓低于7V時集成的電荷泵提供大于10V的柵極驅動.器件的電源電壓5.5V-50V,并和3.3V與5V邏輯電平兼容.本文介紹了A4933主要特性和優勢,方框圖,典型應用電路以及電流檢測放大器配置圖. The A4933 is a 3-phase controller for use with N-channel external power MOSFETs and is specifically designed for automotive applications. A unique charge pump regulator provides full (>10 V) gate drive for battery voltages down to 7 V and allows the A4933 to operate with a reduced gate drive, down to 5.5 V. A bootstrap capacitor is used to provide the above-battery supply voltage required for N-channel MOSFETs. An internal charge pump for the high-side drive allows DC (100% duty cycle) operation. Full control over all six power FETs in the 3-phase bridge is provided, allowing motors to be driven with block commutation or sinusoidal excitation. The power FETs are protected from shoot-through by integrated crossover control and resistor adjustable dead time. Bridge current can be measured using an integrated current sense amplifier. This is an uncommitted differential amplifier with a below-ground common mode range allowing it to be used in low-side current sense applications. Gain and offset are defined by external resistors. Integrated diagnostics provide indication of undervoltage, overtemperature, and power bridge faults. They can be configured to protect the power FETs under most short circuit conditions. Detailed diagnostics are available as a serial data word. The A4933 is supplied in a 48-pin LQFP with exposed thermal pad, (suffix JP). This is a small footprint (81 mm2) power package. It is lead (Pb) free with 100% matte tin leadframe plating. A4933主要特性和優勢: ▪ High current 3-phase gate drive for large N-channel MOSFETs ▪ Pin compatible with Allegro® A4935KJP ▪ Cross-conduction protection with adjustable dead time ▪ Top-off charge pump for 100% PWM ▪ Charge pump for low supply voltage operation ▪ Uncommitted current sense amplifier ▪ 5.5 to 50 V supply voltage range ▪ Compatible with 3.3 V and 5 V logic ▪ Extensive diagnostic outputs ▪ Low-current sleep mode 
圖1. A4933方框圖
圖2. A4933建議電源路徑圖
圖3. A4933典型應用電路圖
圖4. A4933電流檢測放大器配置圖 詳情請見: http://www.allegromicro.com/en/Products/Part_Numbers/4933/4933.pdf |
