Allegromicro公司的A4933是和外接功率MOSFET一起使用的三相马达控制器.当电池电压低于7V时集成的电荷泵提供大于10V的栅极驱动.器件的电源电压5.5V-50V,并和3.3V与5V逻辑电平兼容.本文介绍了A4933主要特性和优势,方框图,典型应用电路以及电流检测放大器配置图.

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主要特性和优势:

▪ 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

图1. A4933方框图

图2. A4933建议电源路径图

图3. A4933典型应用电路图

图4. A4933电流检测放大器配置图
详情请见:
http://www.allegromicro.com/en/Products/Part_Numbers/4933/4933.pdf