Site Map • Contact Us
中文 • English

High-Performance Power ICs and Hall-Effect Sensors

• Search Allegromicro.com:
  
• Home
• Products
  • • Hall-Effect Sensors
    • Power ICs
    • Power Management
    • Sanken
  • Applications
    • Automotive
    • LED Lighting and Displays
    • Office Automation
    • Portable
  • Part Numbers
  • Design Center
  • Packaging
  • Store
• Corporate
  • About Us
  • Contact Us
  • Environment
  • Facilities
  • Jobs
  • Legal
    • Terms and Conditions
      of Sale
  • Press Room
  • Quality
• Sales
  • Americas
  • Europe
  • Asia Pacific
  • Japan
• Site Map
• Feedback

Related Links:

Datasheets:
A8904: 3-Phase Brushless DC Motor Controller/Driver with Back-EMF Sensing (PDF)

Selection Guides:
Power Integrated Circuits,

Power Motor Drivers,

Power Motor Drivers - Brushless DC

when this product is updated

Product Evaluation Kits:
A8904SLP Product Evaluation Kit

A8904
Three-Phase Brushless DC Motor Controller/Driver with Back-EMF Sensing

Features

• Pin-for-pin replacement for A8902CLBA
• Start-up commutation circuitry
• Sensorless commutation circuitry
• Option of external sector data tachometer signal
• Option of external speed control
• Oscillator operation up to 20 MHz
• Programmable overcurrent limit
• Transconductance gain options: 500 mA/V or 250 mA/V
• Programmable watchdog timer
• Directional control
• Serial port interface
• TTL-compatible inputs
• System diagnostics data-out ported in real time
• Dynamic braking through serial port or external terminal

Description

The A8904 is a 3-phase brushless DC motor controller/driver designed for applications where accurate control of high-speed motors is required. The three half-bridge outputs are low on-resistance, N-channel DMOS devices capable of driving up to 1.2 A. The A8904 provides complete, reliable, self-contained back EMF sensing, motor start-up, and running algorithms. A programmable digital frequency-locked loop speed control circuit together with the linear current control circuitry provides precise motor speed regulation.

A serial port allows the user to program various features and modes of operation, such as the speed control parameters, start-up current limit, sleep mode, direction, and diagnostic modes.

The A8904 is fabricated in the Allegro® BCD (Bipolar CMOS DMOS) process, an advanced mixed-signal technology that combines bipolar, analog, and digital CMOS, with DMOS power devices.

The device is provided in a 24-pin wide-body SOIC package, with 4 internally-fused leads for enhanced thermal dissipation (package LB), and a thin (<1.2 mm overall height), 28-pin TSSOP package with an exposed thermal pad Package LP). Both packages are lead (Pb) free, with 100% matte tin leadframe plating.

Functional Block Diagram

Complete Part Numbers

Part Number	Package Type	RoHS Compliant	Part Composition/ RoHS Data	Temperature	Comments	Samples	Distributor Stock
A8904SLB-T	24-lead SOIC	Yes	view data	-20 °C to  85 °C	new	Due to warehouse relocation, samples will be unavailable until August 1, 2008. Contact your sales rep or purchase from distributor.
A8904SLBTR-T	24-lead SOIC	Yes	view data	-20 °C to  85 °C	new	Due to warehouse relocation, samples will be unavailable until August 1, 2008. Contact your sales rep or purchase from distributor.
A8904SLP-T	28-lead TSSOP	Yes	view data	-20 °C to  85 °C	new	Due to warehouse relocation, samples will be unavailable until August 1, 2008. Contact your sales rep or purchase from distributor.
A8904SLPTR-T	28-lead TSSOP	Yes	view data	-20 °C to  85 °C	new	Due to warehouse relocation, samples will be unavailable until August 1, 2008. Contact your sales rep or purchase from distributor.

Allegro's products are not to be used in life support devices or systems, if a failure of an Allegro product can reasonably be expected to cause the failure of that life support device or system, or to affect the safety or effectiveness of that device or system.