THB6128 Stepper Motor Driver Control Module Instruction Manual

1. Product Overview

The THB6128 Stepper Motor Driver Control Module is designed to drive 57 and similar two-phase, four-wire stepper motors. It is built around the original Toshiba THB6128 stepper motor drive chip, offering robust performance and precise control for various applications.

2. Key Features

• High-Efficiency Driver: Utilizes a double full-bridge MOSFET driver with a low on-resistance (Ron = 0.55Ω) for efficient power delivery.
• Wide Voltage & Current Range: Supports a maximum voltage of 36V, with a peak current of 2.2A and a continuous current of 2A. Current settings are easily adjustable via DIP switches.
• Flexible Subdivision Options: Offers a wide range of subdivision settings including 1, 2, 4, 8, 16, 32, 64, and 128, configurable via DIP switches for precise motor control.
• Automatic Half-Flow Lock: Features an automatic half-flow lock function that significantly reduces heat generation when the motor is in a locked state.
• Integrated Protections: Built-in temperature protection and over-current protection enhance reliability and safety.
• Optimized Logic Signal Supply: Includes a built-in 5V logic signal supply regulator chip and a current limiting resistor to manage heat when high input voltages are used.
• Reverse Polarity Protection: Input voltage side is protected against reverse polarity connections.
• Robust Design: Features reasonable component alignment, clear identification, and stable, reliable operation.

3. Technical Specifications

4. Setup and Installation

4.1 Module Pinout

Refer to the diagram below for the pin assignments of the THB6128 driver board.

• 1. CP+ (Pulse positive input)
• 2. CP- (Pulse negative input)
• 3. DIR+ (Direction positive input)
• 4. DIR- (Direction negative input)
• 5. EN+ (Enable positive input)
• 6. EN- (Enable negative input)
• 7. B- (Motor B phase negative output)
• 8. B+ (Motor B phase positive output)
• 9. A- (Motor A phase negative output)
• 10. A+ (Motor A phase positive output)
• 11. VG (Supply negative)
• 12. VM (Power supply positive)

4.2 Signal Interface

The module features three sets of input signals: CP (pulse), DIR (direction), and EN (enable). The electrical diagram for the signal input is shown below.

When the external signal amplitude is between 3.3V and 5V, the current limiting resistor 'R' is not required. If the signal amplitude exceeds 5V, an input signal current limiting resistor 'R' must be connected to ensure the optocoupler input current remains between 8mA and 15mA.

Calculation for Resistor R:

The optocoupler conduction voltage drop is typically 1.1V to 1.3V (use 1.2V for calculation).

Optocoupler current = (Voltage Amplitude - 1.2V) / (R + 330Ω)

Special Note: If the optocoupler operating current exceeds 20mA, the optocoupler's lifespan will be significantly reduced.

The input signal interface supports both common anode and common cathode connections:

• Common Anode Connection: Connect CP+, DIR+, and EN+ to the control system's power supply. The signal is input from the CP-, DIR-, and EN- sides and is active at a low logic level.
• Common Cathode Connection: Connect CP-, DIR-, and EN- to the control system's ground (SGND, isolated from the power supply). The signal is input from the CP+, DIR+, and EN+ sides and is active at a high logic level.

5. Operating Instructions

5.1 Subdivision Settings

The subdivision for the stepper motor is configured using DIP switch S2. The corresponding settings are detailed in the table below.

For a hybrid two-phase stepper motor, the step angle is typically 1.8°, meaning 200 steps per full rotation (360° / 1.8° = 200 steps). The number of pulses for a single turn is calculated as 200 * n, where 'n' is the subdivision value.

For example, if using 16 subdivision, a single turn requires 200 * 16 = 3200 pulses. This means inputting 3200 pulses to the CP terminal will cause the stepping motor to complete one full rotation.

5.2 Current Setting

The module sets the motor current by providing a reference voltage to the chip's VREF pin via a resistor divider network. DIP switch S1 is used to select the resistance, thereby defining the current. The common current settings are shown in the table below.

Other current settings can be achieved by different combinations of the DIP switches. The actual motor phase current can be calculated by measuring the voltage at the Vref test point:

• When the motor is running: Motor phase current = Vref * 2
• When the motor is locked: Due to the half-flow lock function, Vref is automatically halved. Motor phase current = Vref * 4

5.3 Current Attenuation Mode

The module uses two 4.7KΩ resistors to set the VFDT pin voltage to approximately 2.5V, which corresponds to the mixed attenuation mode. This is the most commonly used mode and ensures normal motor operation at both high and low speeds. If a different attenuation mode is required, the voltage divider for the VFDT pin must be adjusted. The FDT voltage and corresponding attenuation modes are provided in the chip manual and summarized below.

6. Troubleshooting

If you encounter issues with the THB6128 module, consider the following general troubleshooting steps:

• No Motor Movement: Check power supply connections (VM, VG) and ensure they are correct and within the specified voltage range. Verify signal connections (CP, DIR, EN) and ensure they are receiving appropriate logic levels. Confirm DIP switch settings for subdivision and current are correct for your motor.
• Motor Jitter/Erratic Movement: Review subdivision and current settings. Incorrect settings can lead to unstable operation. Check for loose wiring or poor connections. Ensure the signal input current is within the recommended 8mA-15mA range, especially if using signal amplitudes above 5V.
• Overheating: While the module has built-in temperature protection and half-flow lock, excessive current or inadequate heat dissipation can cause overheating. Ensure the motor current is set appropriately for your motor and application. Consider adding a heatsink if continuous high current operation is required.
• No Response to Signals: Verify that the control signals (CP, DIR, EN) are correctly wired and that the common anode/cathode configuration matches your control system. Check for any short circuits or open circuits in the signal lines.

7. Maintenance

The THB6128 Stepper Motor Driver Control Module is designed for reliable operation with minimal maintenance. To ensure longevity and optimal performance:

• Keep Clean: Periodically clean the module to prevent dust and debris accumulation, which can affect heat dissipation and electrical connections. Use a soft, dry brush or compressed air.
• Environmental Conditions: Operate the module within its specified environmental conditions (temperature, humidity) to prevent damage.
• Inspect Connections: Regularly check all wiring connections for tightness and signs of wear or corrosion.
• Avoid Overloading: Ensure the motor current settings do not exceed the motor's or module's continuous current ratings to prevent premature wear or failure.

8. User Tips

No specific user tips were available from reviews or Q&A for this product. However, general best practices for stepper motor drivers include:

• Always disconnect power before making any wiring changes to prevent damage to the module or connected components.
• Start with lower current settings and gradually increase if needed, monitoring motor temperature.
• Ensure proper grounding for all components in your system to avoid noise and interference.

9. Warranty and Support

For warranty information and technical support, please refer to the seller's policies or contact the manufacturer directly. Keep your purchase receipt as proof of purchase.