Overview
The A4950ELJTR-T, produced by Allegro MicroSystems, is a Full-Bridge DMOS PWM Motor Driver designed for pulse width modulated (PWM) control of DC motors. This device is capable of handling peak output currents up to ±3.5 A and operating voltages up to 40 V. It is particularly suited for applications requiring efficient and reliable motor control, with features such as internal synchronous rectification to reduce power dissipation and comprehensive protection circuitry.
Key Specifications
| Characteristic | Symbol | Notes | Rating | Unit |
|---|---|---|---|---|
| Load Supply Voltage | VBB | 8 to 40 | V | |
| Logic Input Voltage Range | VIN | –0.3 to 6 | V | |
| VREF Input Voltage Range | VREF | –0.3 to 6 | V | |
| Sense Voltage (LSS pin) | VS | –0.5 to 0.5 | V | |
| Motor Outputs Voltage | VOUT | –2 to 42 | V | |
| Output Current | IOUT | Duty cycle = 100% | 3.5 | A |
| Transient Output Current | iOUT | TW < 500 ns | 6 | A |
| Operating Temperature Range | TA | Temperature Range E | –40 to 85 | °C |
| Operating Temperature Range | TA | Temperature Range K | –40 to 125 | °C |
| Maximum Junction Temperature | TJ(max) | 150 | °C | |
| Storage Temperature Range | Tstg | –55 to 150 | °C | |
| Package Thermal Resistance | RθJA | On 2-layer PCB with 0.8 in^2 exposed 2-oz. copper each side | 62 | °C/W |
| Package Thermal Resistance | RθJA | On 4-layer PCB based on JEDEC standard | 35 | °C/W |
Key Features
- High Current Capability: The A4950 can handle peak output currents up to ±3.5 A and transient output currents up to 6 A for short durations.
- Internal Synchronous Rectification: Reduces power dissipation during PWM operation.
- Comprehensive Protection Circuitry: Includes overcurrent protection, motor lead short to ground or supply, thermal shutdown with hysteresis, undervoltage monitoring of VBB, and crossover-current protection.
- Low Power Standby Mode: Activated when both input signals are in the standby state, reducing power consumption to as low as 10 µA.
- Automotive Grade Option: The A4950K version is designed for high ambient operating temperature applications and is tested across extended temperature and voltage ranges.
- Compact Packaging: Available in an 8-pin SOICN package with an exposed thermal pad for enhanced thermal dissipation.
Applications
- Automotive Systems: Suitable for automotive applications due to its robust protection features and extended temperature range (A4950K version).
- Industrial Automation: Used in industrial motor control systems where reliability and efficiency are critical.
- Consumer Electronics: Applicable in various consumer electronics that require DC motor control, such as fans, pumps, and other motor-driven devices.
- Robotics and Mechatronics: Ideal for robotic systems and mechatronic devices that need precise and efficient motor control.
Q & A
- What is the maximum output current of the A4950?
The A4950 can handle peak output currents up to ±3.5 A.
- What is the operating voltage range of the A4950?
The operating voltage range is from 8 V to 40 V.
- What type of protection circuitry does the A4950 include?
The A4950 includes overcurrent protection, motor lead short to ground or supply, thermal shutdown with hysteresis, undervoltage monitoring of VBB, and crossover-current protection.
- What is the purpose of the internal synchronous rectification in the A4950?
The internal synchronous rectification reduces power dissipation during PWM operation.
- Is the A4950 available in an automotive grade version?
Yes, the A4950K version is designed for high ambient operating temperature applications and is tested across extended temperature and voltage ranges.
- What is the package type of the A4950?
The A4950 is available in an 8-pin SOICN package with an exposed thermal pad.
- How does the low power standby mode work in the A4950?
The low power standby mode is activated when both input signals are in the standby state, reducing power consumption to as low as 10 µA.
- What is the maximum junction temperature of the A4950?
The maximum junction temperature is 150 °C.
- What are some common applications of the A4950?
The A4950 is commonly used in automotive systems, industrial automation, consumer electronics, and robotics and mechatronics.
- How does the thermal shutdown feature work in the A4950?
The thermal shutdown feature activates when the junction temperature exceeds 160 °C and includes a hysteresis of 15 °C for recovery.
