A4941GLPTR-T

A4941 Three-Phase Sensorless Fan Driver Not for New Design These parts are in production but have been determined to be NOT FOR NEW DESIGN. This classification indicates that sale of this device is currently restricted to existing customer applications. The device should not be purchased for new design applications because obsolescence in the near future is probable. Samples are no longer available. Date of status change: September 3, 2018 Recommended Substitutions: For existing customer transition, and for new customers or new applications, contact factory. NOTE: For detailed information on purchasing options, contact your local Allegro field applications engineer or sales representative. Allegro MicroSystems reserves the right to make, from time to time, revisions to the anticipated product life cycle plan for a product to accommodate changes in production capabilities, alternative product availabilities, or market demand. The information included herein is believed to be accurate and reliable. However, Allegro MicroSystems assumes no responsibility for its use; nor for any infringements of patents or other rights of third parties which may result from its use. A4941 Three-Phase Sensorless Fan Driver FEATURES AND BENEFITS • Sensorless (no Hall sensors required) • Soft switching for reduced audible noise • Minimal external components • PWM speed input • FG speed output • Low power standby mode • Lock detection • Optional overcurrent protection • Variant A automotive qualified to AEC-Q100 Grade 2 PACKAGE: 16-pin TSSOP with exposed thermal pad (suffix LP) DESCRIPTION The A4941 three-phase motor driver incorporates BEMF sensing to eliminate the requirement for Hall sensors in fan applications. A pulse wave modulated (PWM) input is provided to control motor speed, allowing system cost savings by eliminating external variable power supply. PWM input can also be used as an on/off switch to disable motor operation and place the IC into a low power standby mode. The A4941 is provided in a 16-pin TSSOP package (suffix LP) with an exposed thermal pad. It is lead (Pb) free, with 100% matte tin leadframe plating. Not to scale Functional Block Diagram 12 V 0.1 µF VCP 0.1 µF CP1 VBB CP2 Charge Pump 10 µF +VINT OUTA SLEW Soft Switch PWM Control Logic 3-Phase Half Bridges 25 kHz OSC VBB 0.167 Ω TEST Sequencer (Direction) Startup OSC CTAP CDCOM Adaptive Commutation Delay + FG FCOM OUTA OUTB – 10 kΩ GND – FC + O/C M SENSE OCP Timers OUTB OUTC OUTC GND + – BEMF Comparator A4941-DS, Rev. 7 MCO-0000509 October 7, 2019 A4941 Three-Phase Sensorless Fan Driver SELECTION GUIDE Part Number Application Packing A4941GLPTR-T Commerical/Industrial 4000 pieces per 13-in. reel A4941GLPTR-A-T Automotive 4000 pieces per 13-in. reel ABSOLUTE MAXIMUM RATINGS Characteristic Supply Voltage Logic Input Voltage Range Symbol Notes Rating Unit VBB VIN Logic Output Voltage VOUT Output Current IOUT 20 V PWM, SLEW –0.3 to 5.5 V FC –0.3 to VBB V FG VBB V Peak (startup and lock rotor) 1.25 A r m s , duty cycle = 100% 900 mA Operating Ambient Temperature TA –40 to 105 °C Maximum Junction Temperature TJ(max) 150 °C Tstg –55 to 150 °C Storage Temperature G temperature range RECOMMENDED OPERATING CONDITIONS Characteristic Supply Voltage Output Current Symbol Conditions Min. VBB IOUT Typ. Max. Unit 5 – 16 V Peak (startup and lock rotor) – – 1 A Run current – 1.5 A rated D2 15 V R1 0.167 Ω FG pull-up resistor, can be pulled-up to VBB if required Optional blocking diode for supply reverse polarity protection Transient voltage suppressor (TVS) Current limiting sense resistor, required for low resistance motors Absolute Maximum table, then simply connect the SENSE pin to ground. That is: • If (VBB(max) / Rmotor ) < 1.25 A, eliminate RS. • If (VBB(max) / Rmotor ) > IOUT (max), the choice of RS determines the current limit setting; recommended range is 167 mΩ < RS < 250 mΩ. Note: For some motor types, use of the current limit circuit may prevent proper startup due to the effect of the chopping on the BEMF voltage appearing on the tri-stated winding. LAYOUT NOTES • Connect GND pins (5,11) to exposed pad ground area under package. • Add thermal vias from exposed pad to bottom side ground plane. • Place VBB decoupling capacitor as close to the IC as possible. • Place sense resistor, (if used), as close to the IC as possible. Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 8 A4941 Three-Phase Sensorless Fan Driver Package LP, 16-Pin TSSOP with Exposed Thermal Pad 0.45 5.00±0.10 16 0.65 16 8º 0º 0.20 0.09 1.70 B 3 NOM 4.40±0.10 3.00 6.40±0.20 6.10 0.60 ±0.15 A 1 1.00 REF 2 3 NOM 0.25 BSC Branded Face 16X SEATING PLANE 0.10 C 0.30 0.19 SEATING PLANE GAUGE PLANE C 3.00 C PCB Layout Reference View For Reference Only; not for tooling use (reference MO-153 ABT) Dimensions in millimeters Dimensions exclusive of mold flash, gate burrs, and dambar protrusions Exact case and lead configuration at supplier discretion within limits shown 1.20 MAX 0.65 BSC 1 2 0.15 0.00 A Terminal #1 mark area B Exposed thermal pad (bottom surface); dimensions may vary with device C Reference land pattern layout (reference IPC7351 SOP65P640X110-17M); All pads a minimum of 0.20 mm from all adjacent pads; adjust as necessary to meet application process requirements and PCB layout tolerances; when mounting on a multilayer PCB, thermal vias at the exposed thermal pad land can improve thermal dissipation (reference EIA/JEDEC Standard JESD51-5) Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 9 A4941 Three-Phase Sensorless Fan Driver REVISION HISTORY Number Date Description 4 December 20, 2012 5 February 24, 2015 6 September 21, 2018 7 October 7, 2019 Add information on CTAP, Automotive variant Added to CTAP information Updated product status to not for new design; minor editorial updates Minor editorial updates Copyright 2019, Allegro MicroSystems. Allegro MicroSystems reserves the right to make, from time to time, such departures from the detail specifications as may be required to permit improvements in the performance, reliability, or manufacturability of its products. Before placing an order, the user is cautioned to verify that the information being relied upon is current. Allegro’s products are not to be used in any devices or systems, including but not limited to life support devices or systems, in which a failure of Allegro’s product can reasonably be expected to cause bodily harm. The information included herein is believed to be accurate and reliable. However, Allegro MicroSystems assumes no responsibility for its use; nor for any infringement of patents or other rights of third parties which may result from its use. Copies of this document are considered uncontrolled documents. For the latest version of this document, visit our website: www.allegromicro.com Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 10