FEATURES
Two-Quadrant and Four-Quadrant Operation
Integrated Absolute Value Current Amplifier
Pulse-by-Pulse and Average Current Sensing
Accurate, Variable Duty-Cycle Tachometer
Output
Trimmed Precision Reference
Precision Oscillator
Direction Output

DESCRIPTION
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. Rotor position inputs are decoded to
provide six outputs that control an external power
stage. A precision triangle oscillator and latched
comparator provide PWM motor control in either
voltage- 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-quadrant applications.
The device includes a differential current-sense
amplifier and absolute-value circuit which provide
an accurate reconstruction of motor current,
useful for pulse-by-pulse overcurrent protection,
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 analog
feedback signal. Other features include COAST,
BRAKE, and DIR_IN commands, along with a
direction output, DIR_OUT.