The UCC3626 motor controller device combines many of the functions required to design a high-performance, two- or four-quadrant, threephase, brushless dc motor controller into one package. SN74S225N Texas Instruments(TI) IC ASYNC FIFO MEMORY 16X5 20DIP  Rotor position inputs are decoded to provide six outputs that control an external power stage. SN74S225N Texas Instruments(TI) IC ASYNC FIFO MEMORY 16X5 20DIP A precision triangle oscillator and latched comparator provide PWM motor control in eithervoltage- or current-mode configurations. The oscillator is easily synchronized to an external master clock source via the SYNCH input. Additionally, a QUAD select input configures the chip to modulate either the low-side switches only, or both upper and lower switches, allowing the user to minimize switching losses in less demanding two-quadrantapplications. SN74S225N Texas Instruments(TI) IC ASYNC FIFO MEMORY 16X5 20DIP The device includes a differential current-sense amplifier and absolute-value circuit which provide an accuratereconstruction of motor current, useful for pulse-by-pulse overcurrent protection, SN74S225N Texas Instruments(TI) IC ASYNC FIFO MEMORY 16X5 20DIP as well as closing a current control loop. A precision tachometer is also provided for implementing closed-loop speed control. The TACH_OUT signal is a variable duty-cycle, frequency output, which can be used directly for digital control or filtered to provide an analogfeedback signal. Other features include COAST, BRAKE, and DIR_IN commands, along with a direction output, DIR_OUT.