Features

• 32-bit position, velocity, and acceleration registers
• Programmable digital PID filter with 16-bit coefficients
• Programmable derivative sampling interval
• 8- or 12-bit DAC output data (LM628)
• 8-bit sign-magnitude PWM output data (LM629)
• Internal trapezoidal velocity profile generator
• Velocity, target position, and filter parameters may be changed during motion
• Position and velocity modes of operation
• Real-time programmable host interrupts
• 8-bit parallel asynchronous host interface
• Quadrature incremental encoder interface with index pulse input
• Available in a 28-pin dual in-line package or a 24-pin surface mount package (LM629 only)

Description

The LM628/LM629 are dedicated motion-control processors designed for use with a variety of DC and brushless DC servo motors, and other servomechanisms which provide a quadrature incremental position feedback signal. The parts perform the intensive, real-time computational tasks required for high performance digital motion control. The host control software interface is facilitated by a high-level command set. The LM628 has an 8-bit output which can drive either an 8-bit or a 12-bit DAC. The components required to build a servo system are reduced to the DC motor/actuator, an incremental encoder, a DAC, a power amplifier, and the LM628. An LM629-based system is similar, except that it provides an 8-bit PWM output for directly driving H-switches. The parts are fabricated in NMOS and packaged in a 28-pin dual in-line package or a 24-pin surface mount package (LM629 only). Both 6 MHz and 8 MHz maximum frequency versions are available with the suffixes -6 and -8, respectively, used to designate the versions. They incorporate an SDA core processor and cells designed by SDA.