Datasheet

1. General description
The PCA9629 is an I
2
C-bus controlled low-power CMOS device that provides all the logic
and control required to drive a four phase stepper motor. PCA9629 is intended to be used
with external high current drivers to drive the motor coils. The PCA9629 supports three
stepper motor drive formats: one-phase (wave drive), two-phase, and half-step. In
addition, when used as inputs, four General Purpose Input/Outputs (GPIOs) allow sensing
of logic level output from optical interrupter modules and generate active LOW interrupt
signal on the INT
pin of PCA9629. This is a useful feature in sensing home position of
motor shaft or reference for step pulses. Upon interrupt, the PCA9629 can be
programmed to automatically stop the motor or reverse the direction of rotation of motor.
Output wave train is programmable using control registers. The control registers are
programmed via the I
2
C-bus. Features built into the PCA9629 provide highly flexible
control of stepper motor, off-load bus master/micro and significantly reduce I
2
C-bus traffic.
These include control of step size, number of steps per single command, number of full
rotations and direction of rotation. A ramp-up on start and/or ramp-down on stop is also
provided.
The PCA9629 is available in a 16-pin TSSOP package and is specified over the 40 C to
+85 C industrial temperature range.
2. Features and benefits
 Generate motor coil drive phase sequence signals with four outputs for use with
external high current drivers to off-load CPU
 Four balanced push-pull type outputs capable of sinking 25 mA or sourcing 25 mA for
glueless connection to external high current drivers needed to drive motor coils
 Up to 1000 pF loads with 100 ns rise and fall times
 Built-in oscillator requires no external components
 Stepper motor drive control logic
 One-phase (wave drive), two-phase, and half-step drive format logic level outputs
 Programmable step rate: 344.8 kpps to 0.3 pps with 5 % accuracy
 Programmable ramp-up on start and ramp-down to stop
 Programmable steps and rotation control
 Sensor enabled drive control: linked to interrupt from I/O pins
 Direction control of motor shaft
 Selectable active hold, power off or released states for motor shaft
PCA9629
Fm+ I
2
C-bus stepper motor controller
Rev. 1 — 29 February 2012 Product data sheet