UCC2626, UCC3626
SLUS318B – APRIL 1999 – REVISED JANUARY 2002
BRUSHLESS DC
MOTOR CONTROLLER
FEATURES
D Two-Quadrant and Four-Quadrant Operation
D Integrated Absolute Value Current Amplifier
D Pulse-by-Pulse and Average Current Sensing
D Accurate, Variable Duty-Cycle Tachometer
Output
D Trimmed Precision Reference
D Precision Oscillator
D Direction Output
DESCRIPTION
The UCC3626 motor controller device combines
many of the functions required to design a
high-performance, two- or four-quadrant, three-
phase, 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.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
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Copyright 2002, Texas Instruments Incorporated
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