Overview
The A4989SLDTR-T, produced by Allegro MicroSystems, is a dual full-bridge gate driver with an integrated microstepping translator. This device is designed to drive a wide range of higher power industrial bipolar two-phase stepper motors, typically in the power range of 30 to 500 W. It operates with external N-channel power MOSFETs at supply voltages from 12 to 50 V, making it a versatile solution for various industrial motor applications.
Key Specifications
| Parameter | Min. | Typ. | Max. | Units |
|---|---|---|---|---|
| Supply Voltage (VBB) | 12 | - | 50 | V |
| Operating Ambient Temperature (TA) | -20 | - | 85 | °C |
| Junction Temperature (TJ) | - | - | 150 | °C |
| Storage Temperature (Tstg) | -55 | - | 150 | °C |
| Blank Time (tBLANK) | 1.2 | 1.5 | 1.8 | µs |
| Fixed Off-Time (tOFF) | 18.12 | - | 23.16 | µs |
| Reference Input Voltage (VREF) | 0.8 | - | 2 | V |
| Internal Reference Voltage (VREFInt) | 1.9 | 2.0 | 2.1 | V |
| Oscillator Frequency (fOSC) | 3.2 | 4 | 4.8 | MHz |
| Undervoltage Lockout (VREGUV) | 7.5 | 8 | 8.5 | V |
| Package Type | 38-pin TSSOP (LD) | - | ||
Key Features
- Integrated Microstepping Translator: Provides microstepping control at full-, half-, quarter-, and sixteenth-step resolutions without the need for complex phase-sequence tables or high-frequency control lines.
- Dual Full-Bridge Gate Driver: Drives external N-channel power MOSFETs for high efficiency and cost-effectiveness.
- Fixed Off-Time PWM Current Control: Regulates current in each full-bridge independently, with the ability to operate in slow-, mixed-, or fast-decay modes to reduce audible motor noise and power dissipation.
- Two-Wire Step and Direction Interface: Simplifies motor control by requiring only one pulse on the STEP input to drive the motor one step.
- Internal Circuit Protection: Includes thermal shutdown with hysteresis and undervoltage lockout for enhanced reliability.
- Synchronous Rectification and Crossover Control: Enhances efficiency and protects power FETs from shoot-through.
- Lead-Free Packaging: 38-pin TSSOP package with 100% matte tin leadframe plating.
Applications
The A4989SLDTR-T is suitable for a wide range of industrial applications involving bipolar two-phase stepper motors, including but not limited to:
- Industrial automation systems
- Medical devices requiring precise motor control
- 3D printers and CNC machines
- Robotic systems
- High-precision positioning systems
Q & A
- What is the A4989SLDTR-T used for?
The A4989SLDTR-T is a dual full-bridge gate driver with an integrated microstepping translator, used for driving bipolar two-phase stepper motors.
- What are the supply voltage ranges for the A4989SLDTR-T?
The device operates with supply voltages from 12 to 50 V.
- What microstepping resolutions does the A4989SLDTR-T support?
The device supports full-, half-, quarter-, and sixteenth-step resolutions.
- How does the A4989SLDTR-T control motor stepping?
Motor stepping is controlled by a two-wire step and direction interface.
- What protection features does the A4989SLDTR-T include?
The device includes thermal shutdown with hysteresis, undervoltage lockout, and crossover current control to protect the power FETs.
- What is the package type of the A4989SLDTR-T?
The device is packaged in a 38-pin TSSOP (LD) package.
- What are the operating temperature ranges for the A4989SLDTR-T?
The operating ambient temperature range is -20 to 85°C, and the junction temperature should not exceed 150°C.
- How does the fixed off-time PWM current control work?
The fixed off-time PWM current control regulates the current in each full-bridge independently, operating in slow-, mixed-, or fast-decay modes.
- Does the A4989SLDTR-T require special power-up sequencing?
No, special power-up sequencing is not required.
- What is the purpose of the bootstrap capacitor in the A4989SLDTR-T?
The bootstrap capacitor provides the above-supply voltage required for the high-side N-channel MOSFETs.
