Overview
The L6235QTR, produced by STMicroelectronics, is a DMOS fully integrated 3-phase motor driver designed for driving 3-phase brushless DC (BLDC) motors. This device is realized in BCDmultipower technology, combining isolated DMOS power transistors with CMOS and bipolar circuits on the same chip. It includes all the necessary circuitry to drive a 3-phase BLDC motor, such as a 3-phase DMOS bridge, a constant OFF time PWM current controller, and decoding logic for single-ended Hall sensors. The L6235QTR is available in a QFN48 7x7 package and features non-dissipative overcurrent protection and thermal shutdown.
Key Specifications
| Parameter | Min. | Typ. | Max. | Unit |
|---|---|---|---|---|
| Operating Supply Voltage | 8 | - | 52 | V |
| Output Peak Current | - | 5.6 | - | A |
| RDS(on) High-Side Switch | 0.34 | 0.4 | 0.59 | Ω |
| RDS(on) Low-Side Switch | 0.28 | 0.34 | 0.53 | Ω |
| Operating Frequency | - | - | 100 kHz | - |
| Thermal Shutdown Temperature | - | 165 | - | °C |
| Dead Time Protection | 0.5 | 1 | - | µs |
Key Features
- Operating supply voltage from 8 to 52 V
- 5.6 A output peak current
- Low RDS(on) of 0.3 Ω (typical value at 25 °C)
- Operating frequency up to 100 kHz
- Non-dissipative overcurrent protection
- Diagnostic output
- Constant OFF time PWM current controller
- Slow decay synchronous rectification
- 60° and 120° Hall effect decoding logic
- Brake function
- Tacho output for speed loop
- Cross conduction protection
- Thermal shutdown
- Undervoltage lockout
- Integrated fast freewheeling diodes
Applications
The L6235QTR is suitable for a variety of applications involving 3-phase brushless DC motors, including but not limited to:
- Industrial automation and robotics
- Aerospace and defense systems
- Automotive systems (e.g., electric power steering, fuel pumps)
- Medical devices (e.g., surgical tools, medical pumps)
- Consumer electronics (e.g., fans, pumps, and other motor-driven appliances)
A typical application setup includes connecting the device to a 3-phase BLDC motor, using Hall sensors for position feedback, and implementing necessary power and signal grounding to ensure reliable operation.
Q & A
- What is the operating supply voltage range of the L6235QTR?
The operating supply voltage range is from 8 to 52 V.
- What is the maximum output peak current of the L6235QTR?
The maximum output peak current is 5.6 A.
- What is the typical RDS(on) value of the high-side switch at 25 °C?
The typical RDS(on) value of the high-side switch at 25 °C is 0.4 Ω.
- What is the maximum operating frequency of the L6235QTR?
The maximum operating frequency is up to 100 kHz.
- Does the L6235QTR have overcurrent protection?
Yes, the L6235QTR features non-dissipative overcurrent protection.
- What is the thermal shutdown temperature of the L6235QTR?
The thermal shutdown temperature is typically 165 °C.
- How does the L6235QTR handle cross conduction protection?
The device implements cross conduction protection using a dead time of 1 µs between the turn-off and turn-on of two power MOSFETs in one leg of the bridge.
- What type of logic inputs does the L6235QTR support?
The device supports TTL/CMOS and µC compatible logic inputs.
- How should the sense resistors be connected in an application?
The sense resistors should be connected between the source of the lower power MOSFETs and ground, using non-inductive resistors to minimize di/dt transients.
- What is the recommended way to handle unused logic pins?
Unused logic pins should be connected to 5 V (high logic level) or GND (low logic level) to increase noise immunity.
