Overview
The L297/1 Stepper Motor Controller IC, produced by STMicroelectronics, is designed to generate four-phase drive signals for both two-phase bipolar and four-phase unipolar stepper motors. This IC is particularly suited for microcomputer-controlled applications, reducing the burden on the microprocessor and programmer by generating the phase sequences internally. Available in DIP20 and SO20 packages, the L297/1 can be used with various power stages, including monolithic bridge drivers like the L298N or L293E, or with discrete transistors and Darlington arrays.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Supply Voltage (Vs) | 4.75 - 7 | V |
| Quiescent Supply Current (Is) | 50 - 80 | mA |
| Input Voltage (Vi) | 0.6 - 2 Vs | V |
| Input Current (Ii) | 100 µA (low), 10 µA (high) | µA |
| Enable Input Voltage (Ven) | 1.3 - 2 Vs | V |
| Enable Input Current (Ien) | 100 µA (low), 10 µA (high) | µA |
| Phase Output Voltage (Vo) | 0.4 V (low), 3.9 V (high) | V |
| Inhibit Output Voltage (Vinh) | 0.4 V (low), 3.9 V (high) | V |
| Storage and Junction Temperature | -40 to +150 | °C |
| Total Power Dissipation (Ptot) | 1 | W |
| Thermal Resistance Junction-Ambient (Rth-j-amb) | 80 - 100 | °C/W |
Key Features
- Generates four-phase drive signals for two-phase bipolar and four-phase unipolar stepper motors.
- Supports half-step, normal (two-phase-on), and wave drive (one-phase-on) modes.
- On-chip PWM chopper circuits for switch-mode control of winding currents.
- Programmable load current via a voltage divider on the Vref input.
- Active low inhibit controls for speeding current decay when a winding is de-energized.
- Chip enable input to bring all phase and inhibit outputs low when inactive.
- Reset input to restore the translator to the home position.
- Synchronization capability for multiple L297 configurations to avoid ground noise issues.
Applications
The L297/1 is widely used in microcomputer-controlled stepper motor applications, including but not limited to:
- Industrial automation systems.
- Robotics and mechatronics.
- Medical equipment and diagnostic devices.
- Printers and plotters.
- CNC machines and 3D printers.
Q & A
- What types of stepper motors can the L297/1 control?
The L297/1 can control both two-phase bipolar and four-phase unipolar stepper motors.
- What are the different drive modes supported by the L297/1?
The L297/1 supports half-step, normal (two-phase-on), and wave drive (one-phase-on) modes.
- How does the L297/1 regulate the load current in the motor windings?
The L297/1 uses on-chip PWM chopper circuits to regulate the load current, with the peak current programmable via a voltage divider on the Vref input.
- What is the purpose of the SYNC pin on the L297/1?
The SYNC pin is used to synchronize the chopper oscillators in multiple L297 configurations to avoid ground noise issues.
- How can the direction of the motor be controlled using the L297/1?
The direction of the motor can be controlled using the CW/CCW (clockwise/counterclockwise) direction control input. The physical direction also depends on the connection of the windings.
- What is the function of the RESET input on the L297/1?
The RESET input restores the translator to the home position (state 1, ABCD = 0101) when an active low pulse is applied.
- Can the L297/1 be used with different types of power stages?
Yes, the L297/1 can be used with monolithic bridge drivers like the L298N or L293E, or with discrete transistors and Darlington arrays.
- What is the typical supply current of the L297/1?
The typical quiescent supply current of the L297/1 is 50-80 mA.
- What are the storage and junction temperature limits for the L297/1?
The storage and junction temperature limits for the L297/1 are -40°C to +150°C.
- How does the L297/1 speed up current decay when a winding is de-energized?
The L297/1 generates inhibit signals (INH1 and INH2) that can be used to ensure fast decay of load current when a winding is de-energized.
