风扇转速检测软启动功能PWM控制，单相直流无刷马达的前级驱动芯片

产品概述 返回TOP
CXMD3272是一款用于单相直流无刷马达的前级驱动芯片。CXMD3272内置功能包括软启动功能、PWM控制、小转速设置、Soft Switching功能、风扇转速检测、锁定保护、自动重启和限流检测。它是霍尔芯片与单相直流无刷马达之间的一个控制接口电路。CXMD3272的PWM工作模式控制外部PMOS-NMOS功率管使马达转动时保持低噪声和低抖动，外接PMOS的驱动占空比由它控制。CXMD3272具有软启动功能，可以控制马达启动过程中由低速到高速的加速时间，该时间由连接S-S和5VREG的外接电容决定。小转速设置功能可设定风扇转动时的低速度。如果马达被外部应力或者障碍物卡住，则过驱动电流可能会引起温度升高而损坏马达。为了防止此类现象发生，当马达锁死后，锁定保护电路将关断外置功率管，切断马达驱动。几秒钟后自动重启电路会尝试重新打开功率管恢复驱动。锁定保护时间和自动重启时间可以由芯片外接电容设定。CXMD3272还有转速反馈输出。CXMD3272 is a pre-driver for single coil brushless DC motor, specially designed for 12V power supply application. With an external PWM input signal, CXMD3272 can control the speed of DC motor. It is an interface between a HALL IC and a single coil motor. The functions built in CXMD3272include soft start mode, PWM control mode, minimum speed mode, soft-switching time, fan tachometer, lock protection, auto restart, Hall Bias and current limiter. PWM mode controls the external PMOS-NMOS FET in low noise and low vibration. With soft start function. CXMD3272can drive motor from slow speed to fast speed in a settable time by setting the external capacitor between SS and REG. Minimum speed mode makes the lowest speed of motor settable. Soft-switching time can cut the ineffective current when phase change is not set. If the motor is stalled by external force or obstacles, overdrive current may incur coil overheating. To prevent this, the lock protection circuit shuts down the external power devices for a few seconds after the motor is locked. Then auto restart circuit will resume to power up these devices. The protection and power up time are settable by an external capacitor. CXMD3272has FG output.
产品特点 返回TOP
• 单相全波驱动（功率管外置）
• 软启动功能（启动时的加速时间由连接S-S和5VREG的外接电容决定）
• PWM控制模式（控制外接上臂功率管的占空比）
• Soft Switching功能（切断相位不明确时的驱动电流）
• 小转速设定
• 锁定保护与自动重启
• FG输出
• 限流保护
• TSSOP-16 封装
• 符合RoHS规范及Pb-Free