The PCA9629A is an I²C-bus controlled low-power CMOS device that provides all the logic and control required to drive a four phase stepper motor. PCA9629A is intended to be used with external high current drivers to drive the motor coils. The PCA9629A 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 PCA9629A. This is a useful feature in sensing home position of motor shaft or reference for step pulses. Upon interrupt, the PCA9629A can be programmed to automatically stop the motor, re-start motor, enable extra steps or reverse the direction of rotation of motor.
Output wave train is programmable using control registers. The control registers are programmed via the I²C-bus. Features built into the PCA9629A provide highly flexible control of stepper motor, off-load bus master/micro and significantly reduce I²C-bus traffic. These include control of step size, number of steps per single command, number of actions from 1 to 255 or continuous rotations and direction of rotation. Re-start motor for new speed and operation without waiting for motor stop. A ramp-up on start and/or ramp-down on stop is also provided with re-enable ramp-up or ramp-down to change the ramp rate curve on the fly.
The PCA9629A is available in a 16-pin TSSOP package and is specified over the ‑40 °C to +85 °C industrial temperature range.
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## Features
* 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 unipolar stepper motor coils
* Up to 1000 pF loads with 100 ns rise and fall times
* Built-in 1 MHz 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: 333.3 kpps to 0.3 pps with ±3 % accuracy
* Programmable ramp-up on start and ramp-down to stop
* Programmable re-enable ramp-up or ramp-down to change ramp rate curve on the fly
* Programmable re-start motor with new speed and operation while motor is still running
* Programmable motor action either multiple times (1 to 255) or continuously
* Programmable loop delay timer for motor reversal mode
* Programmable steps with clockwise and/or counter-clockwise control
* Direction control of motor shaft
* Selectable active hold (last state), power on, power off or released states for motor shaft
* 32-bit step counter to count output steps
* Interrupt features
* Active LOW open-drain interrupt output
* Programmable watchdog timer with option to generate interrupt, reset device or stop motor
* Programmable motor stop interrupt
* Sensor enabled drive control: linked to interrupt from GPIO pins
* Programmable interrupt Mask Control for input sources
* Four stepper motor drive outputs: OUT0 to OUT3
* Configured to drive stepper motor outputs and capable to read back the last output states when motor is stopped
* Both output phase and state can be changed at any time
* Programmable time-out timer to set all outputs to zeros when motor is stopped
* Configured as general purpose outputs to drive (source/sink) loads up to 25 mA
* Four general purpose I/Os: P0 to P3
* Configured to sense logic level outputs from optical interrupter photo transistor circuit
* Programmable filter timer to suppress spike or noise for P0 and P1 inputs
* Configured as outputs to drive (source/sink) LEDs or other loads up to 25 mA
* 4.5 V to 5.5 V operation
* 1 MHz Fast-mode Plus (Fm+) compatible I²C-bus serial interface with 30 mA high drive capability on SDA output for driving high capacitive buses
* Active LOW reset (RESET) input pin resets device to power-up default state: can be used to recover from bus stuck condition
* All Call address allows programming of more than one device at the same time with the same parameters
* 16 programmable slave addresses using two address pins
* ‑40 °C to +85 °C operation
* ESD protection exceeds 2000 V HBM per JESD22-A114 and 1000 V CDM per JESD22C101
* Latch-up testing is done to JEDEC Standard JESD78 which exceeds 100 mA
