A4931METTR-T

A4931 3-Phase Brushless DC Motor Pre-Driver FEATURES AND BENEFITS DESCRIPTION ▪ Drives 6 N-channel MOSFETs ▪ Synchronous rectification for low power dissipation ▪ Internal UVLO and thermal shutdown circuitry ▪ Hall element inputs ▪ PWM current limiting ▪ Dead time protection ▪ FG outputs ▪ Standby mode ▪ Lock detect protection ▪ Overvoltage protection The A4931 is a complete 3-phase brushless DC motor pre-driver. The device is capable of driving a wide range of N-channel power MOSFETs and can support motor supply voltages up to 30 V. Commutation logic is determined by three Hall-element inputs spaced at 120°. Other features include fixed off-time pulse-width modulation (PWM) current control for limiting inrush current, locked-rotor protection with adjustable delay, thermal shutdown, overvoltage monitor, and synchronous rectification. Internal synchronous rectification reduces power dissipation by turning on the appropriate MOSFETs during current decay, thus shorting the body diode with the low RDS(on) MOSFET. Overvoltage protection disables synchronous rectification when the motor pumps the supply voltage beyond the overvoltage threshold during current recirculation. PACKAGE: 28-contact QFN (ET package) The A4931 offers enable, direction, and brake inputs that can control current using either phase or enable chopping. Logic outputs FG1 and FG2 can be used to accurately measure motor rotation. Output signals toggle state during Hall transitions, providing an accurate speed output to a microcontroller or speed control circuit. Not to scale The A4931 is supplied in a 5 mm × 5 mm, 28-terminal QFN package with exposed thermal pad. This small footprint package is lead (Pb) free with 100% matte-tin leadframe plating. Typical Application 0.1 µF 0.1 µF 0.1 µF 2 kΩ VIN CLD HBIAS FG1 System Control Logic FG2 BRAKEZ ENABLE DIR CP1 CP2 VCP VBB VIN GHA SA GLA M A4931 0.1 µF GHB SB GLB GHC SC GLC SENSE GND HA+ HA– HB+ HB– HC+ HC– 4931-DS, Rev. 8 MCO-0000383 February 10, 2020 A4931 3-Phase Brushless DC Motor Pre-Driver SELECTION GUIDE Part Number Packing Package Operating Ambient Temperature, TA (°C) A4931METTR-T 1500 pieces per reel 5 mm × 5 mm, 0.90 mm nominal height QFN –20 to 105 A4931GETTR-T 1500 pieces per reel 5 mm × 5 mm, 0.90 mm nominal height QFN –40 to 105 ABSOLUTE MAXIMUM RATINGS Characteristic Symbol Notes Load Supply Voltage VBB Motor Phase Output SX tw < 500 ns Hall Input VHx DC Logic Input Voltage Range VIN Logic Output Voltage Range VFG FG1, FG2 pins Rating Units 38 V –3 V –0.3 to 7 V –0.3 to 7 V –0.3 to 7 V Range M –20 to 105 °C Range G Operating Ambient Temperature TA –40 to 105 °C Maximum Junction Temperature TJ(max) 150 °C Tstg –40 to 150 °C Rating Units 32 °C/W 2 °C/W Storage Temperature THERMAL CHARACTERISTICS Characteristic Symbol Package Thermal Resistance, Junction to Ambient RθJA Package Thermal Resistance, Junction to Exposed Pad RθJP Test Conditions* 4-layer PCB based on JEDEC standard *For additional information, refer to the Allegro website. Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 2 A4931 3-Phase Brushless DC Motor Pre-Driver FUNCTIONAL BLOCK DIAGRAM 0.1 µF CLD Lock Detect CP1 CP2 0.1 µF FG1 VCP CHARGE PUMP 0.1 µF 2 kΩ VBB VREG HA+ HALL Enable 0.1 µF HBIAS HAHB+ HALL VIN OVP VCP Communication Logic VREG GHA SA HBGATE DRIVE HC+ HALL HC- System Logic GHB SB GLB GHC SC GLC Control Logic FG1 FG2 GLA BRAKEZ SENSE DIR RSENSE 200 mV ENABLE VIN GND Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 3 A4931 3-Phase Brushless DC Motor Pre-Driver 22 SA 23 FG1 24 FG2 25 CLD 26 DIR 27 ENABLE 28 BRAKEZ PINOUT DIAGRAM AND TERMINAL LIST HA+ 1 21 GHA HA– 2 20 SB HB+ 3 HB– 4 HC+ 5 17 GHC HC– 6 16 GLA GND 7 15 GLB 19 GHB GLC 14 SENSE 13 18 SC VCP 12 CP2 10 9 CP1 VBB 11 8 HBIAS PAD ET Package Pinout Diagram Terminal List Number Name 1 HA+ 2 HA - 3 HB+ 4 HB - 5 HC+ 6 HC- 7 GND 8 HBIAS 9 CP1 Description Number Name Description Hall input A 15 GLB Low side gate drive B Hall input A 16 GLA Low side gate drive A Hall input B 17 GHC High side gate drive C Hall input B 18 SC Hall input C 19 GHB Hall input C 20 SB High side source connection C High side gate drive B High side source connection B Ground 21 GHA Hall bias power supply output 22 SA High side gate drive A Charge pump capacitor terminal 23 FG1 FG 1 speed control output (3 Φ inputs) High side source connection A 10 CP2 Charge pump capacitor terminal 24 FG2 FG 2 speed control output (ΦA input) 11 VBB Supply voltage 25 CLD Locked rotor detect timing capacitor 12 VCP Reservoir capacitor terminal 26 DIR Logic input – motor direction 13 SENSE Sense resistor connection 27 ENABLE Logic input – external PWM control 14 GLC Low side gate drive C 28 BRAKEZ Logic input – motor brake (active low) Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 4 A4931 3-Phase Brushless DC Motor Pre-Driver ELECTRICAL CHARACTERISTICS*: Valid at TA= 25°C, VBB = 24 V, unless noted otherwise Characteristics Supply Voltage Range Motor Supply Current Symbol VBB IBB Test Conditions Min. Typ. Max. Units Operating 8 – VBBOV V fPWM < 30 kHz, CLOAD = 1000 pF – 5 6 mA – 3 3.5 mA 7.2 7.5 7.8 V IHBIASlim 30 – – mA VIN(1) 2 – – V HBIAS Voltage VHBIAS HBIAS Current Limit Charge pump on, outputs disabled, Standby mode 0 mA ≤ IHBIAS ≤ 24 mA CONTROL LOGIC Logic Input Voltage Logic Input Current Input Pin Glitch Reject VIN(0) – – 0.8 V –1 tlock / 2 Lock Detect Function The IC will evaluate a locked rotor condition under either of these two different conditions: The Lock Detect function can be disabled by connecting CLD to GND. When the A4931 is in Brake mode, the Lock Detect counter is disabled. Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 10 A4931 3-Phase Brushless DC Motor Pre-Driver ET Package, 28-Contact QFN 0.30 5.00 ±0.15 1.15 28 1 2 0.50 28 1 A 5.00 ±0.15 3.15 4.80 3.15 29X D SEATING PLANE 0.08 C +0.05 0.25 –0.07 0.90 ±0.10 0.50 C 4.80 C PCB Layout Reference View Contact the factory for the sidewall plating PCB footprint and assembly instructions. For Reference Only (reference JEDEC MO-220VHHD-1) Dimensions in millimeters Exact case and lead configuration at supplier discretion within limits shown +0.20 0.55 –0.10 B 2 1 28 3.15 3.15 A Terminal #1 mark area B Exposed thermal pad (reference only, terminal #1 identifier appearance at supplier discretion) C Reference land pattern layout (reference IPC7351 QFN50P500X500X100-29V1M); 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) D Coplanarity includes exposed thermal pad and terminals Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com 11 A4931 3-Phase Brushless DC Motor Pre-Driver Revision History Number Date 8 February 10, 2020 Description Added G temperature rated part option; minor editorial updates Copyright 2020, 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 12