A3938 Three-Phase Power MOSFET Controller FEATURES AND BENEFITS DESCRIPTION Drives a wide range of N-channel MOSFETs The A3938 is a three-phase, brushless DC motor controller. Low-side synchronous rectification It has a high-current gate drive capability that allows driving Power MOSFET protection of a wide range of power MOSFETs and can support motor Adjustable dead time for cross-conduction protection supply voltages to 50 V. The A3938 integrates a bootstrapped Selectable coast or dynamic brake on power-down or high-side driver to minimize the external component count RESET input required to drive N-channel MOSFET drivers. Fast/slow current decay modes Internal fixed off-time, PWM current-control circuitry can be Internal PWM current control used to regulate the maximum load current to a desired value. Motor lead short-to-ground protection The peak load current limit is set by the users selection of an Internal 5 V regulator input reference voltage and external sensing resistor. A user- Fault diagnostic output selected external RC timing network sets the fixed off-time Thermal shutdown pulse duration. For added flexibility, the PWM input can provide Undervoltage protection speed/torque control where the internal current control circuit sets a limit on the maximum current. Package 38-pin TSSOP (suffix LD): The A3938 includes a synchronous rectification feature. This shorts out the current path through the power MOSFET reverse body diodes during PWM off-cycle current decay. This can minimize power dissipation in the MOSFETs, eliminate the need for external power clamp diodes, and potentially allow a more economical choice for the MOSFET drivers. The A3938 provides commutation logic for Hall sensors configured for 120-degree spacing. The H-all input pins are pulled-up to an internally-generated 5 V reference. Power MOSFET protection features include: bootstrap capacitor Not to scale charging current monitor, regulator undervoltage monitor, motor lead short-to-ground, and thermal shutdown. The LD package is lead (Pb) free, with 100% matte tin plated leadframe. RESET 1 38 N/C GLC 2 37 N/C SC 3 36 PGND N/C 4 35 AGND 5 34 N/C DEAD 6 33 GHC REF 7 32 CC SENSE 8 31 GLB RC 9 30 SB PWM 10 29 GHB BRKSEL 11 28 CB BRKCAP Control Logic 12 Fault 27 GLA BRAKE 13 26 SA DIR GHA 14 25 H2 CA 15 24 H3 VREG 16 23 N/C LCAP 17 22 H1 N/C 18 21 VBB FAULT 19 20 MODE 26301.104H, Rev. 1 April 10, 2019 MCO-0000647A3938 Three-Phase Power MOSFET Controller Selection Guide Part Number Packing A3938SLDTR-T 4000 per reel ABSOLUTE MAXIMUM RATINGS Characteristic Symbol Notes Rating Units Load Supply Voltage V 50 V BB VREG Pin, Transient V 15 V REG Logic Input Voltage Range V 0.3 to V + 0.3 V IN LCAP Sense Voltage Range V 5 to 1.5 V SENSE Output Voltage Range V SA, SB, SC Pins 5 to 50 V GHA, GHB, GHC Pins 5 to V + 17 V BB CA, CB, CC Pins V + 17 V Sx Operating Ambient Temperature T Range S 20 to 85 C A Junction Temperature T 150 C J Storage Temperature T 55 to 150 C stg THERMAL CHARACTERISTICS (MAY REQUIRE DERATING AT MAXIMUM CONDITIONS) Characteristic Symbol Test Conditions Min. Units Package Thermal Resistance R LD package, 4 layer PCB based on JEDEC standard 51 C/W JA 2 Allegro MicroSystems 955 Perimeter Road Manchester, NH 03103-3353 U.S.A. www.allegromicro.com