A4937 Automotive 3-Phase MOSFET Driver Description Features and Benefits • High current 3-phase gate drive for N-channel MOSFETs • SPI compatible serial control • Cross-conduction protection • Programmable dead time • 5.5 to 50 V supply voltage range • TTL inputs compatible with 3.3 V and 5 V logic • Extensive diagnostics output • Low current sleep mode Applications The A4937 is a 3-phase controller for use with N-channel external power MOSFETs and is specifically designed for automotive applications. A unique charge pump regulator provides full (>10 V) gate drive for battery voltages down to 7 V and allows the A4937 to operate with a reduced gate drive, down to 5.5 V. A bootstrap capacitor is used to provide the above battery supply voltage required for N-channel MOSFETs. Full control over all six power MOSFETs in the 3-phase bridge is provided, through an SPI compatible serial interface, allowing motors to be driven with block or overlap commutation. Power output can be regulated by one or both of the PWM inputs. The power MOSFETs are protected from shoot-through by integrated crossover control and programmable dead time. • Electronic power steering (EPS, EHPS, EAS) • Hydraulic pumps • Gearbox actuator Integrated diagnostics provide indication of undervoltage, overtemperature, and power bridge faults, and can be configured to protect the power MOSFETs under most short circuit conditions. Detailed diagnostics are available as a serial data word. Package: 28-pin TSSOP with Exposed Thermal Pad (suffix LP) The A4937 is supplied in a 28-pin TSSOP power package with with exposed pad for enhanced thermal dissipation (package type LP). This package is lead (Pb) free, with 100% matte-tin leadframe plating. Not to scale Functional Block Diagram VBAT A8450 VBAT Regulator SPI Microcontroller PWM Reset Diagnostics A4937A-DS A4937 3-Phase BLDC Motor A4937 Automotive 3-Phase MOSFET Driver Selection Guide Part Number Packing* A4937KLPTR-A-T 4000 pieces per 13-in. reel Package 4.4 mm × 9.7 mm, 1.2 mm maximum height TSSOP with exposed thermal pad *Contact Allegro™ for additional packing options. Absolute Maximum Ratings* Characteristic Symbol Notes Rating Unit Load Supply Voltage VBB –0.3 to 50 V Logic Supply Voltage VDD –0.3 to 6 V Terminal VREG VREG –0.3 to 16 V Terminal CP1 VCP1 –0.3 to 16 V VCP2 VCP1 – 0.3 to VREG + 0.3 V –0.3 to 6 V –0.3 to 6 V –0.3 to VDD + 0.3 V Terminal CP2 STRn, SCK, SDI, PWMH, PWML Logic Inputs VI Logic Outputs VO Terminal DIAG VDIAG –0.3 to VDD + 0.3 V Terminal VBRG VBRG –5 to 55 V VCx –0.3 to VREG + 50 V VGHx VCx – 16 to VCx + 0.3 V VSx VCx – 16 to VCx + 0.3 V Terminals GLA, GLB, GLC VGLx VREG – 16 to 18 V Terminal LSS VLSS VREG – 16 to 18 V –40 to 150 °C 150 °C 175 °C –55 to 150 °C Terminals CA, CB, CC Terminals GHA, GHB, GHC Terminals SA, SB, SC Ambient Operating Temperature Range TA Maximum Continuous Junction Temperature TJ(max) Transient Junction Temperature TtJ Storage Temperature Range Tstg RESETn; can be pulled to VBB with >22 kΩ SDO Limited by power dissipation Overtemperature event not exceeding 10s, lifetime duration not exceeding 10 hours, guaranteed by design characterization. *With respect to GND. Ratings apply when no other circuit operating constraints are present. Thermal Characteristics may require derating at maximum conditions Characteristic Symbol Package Thermal Resistance (Junction to Ambient) RθJA Package Thermal Resistance (Junction to Pad) RθJP Value Unit On 4-layer PCB based on JEDEC standard Test Conditions* 28 ºC/W 2-layer PCB with 3.8 in.2 of copper area each side 32 ºC/W 2 ºC/W *Additional thermal information available on the Allegro website. Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 2 A4937 Automotive 3-Phase MOSFET Driver Functional Block Diagram Battery + CP VDD CP1 CP2 VBB RESETn Charge Pump Regulator VBAT VREG CREG VBRG Phase A CA PWMH CBOOTA PWML High Side Drive Control Logic Bootstrap Monitor VDS Monitor GHA One of three phases shown RGATE SA VDS Monitor VREG Low Side Drive GLA RGATE Phase C Phase B LSS STRn SCK SDI SDO DIAG Serial Interface Diagnostics and Protection GND Allegro MicroSystems, LLC 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000; www.allegromicro.com 3