DESCRIPTION
The Si9979 is a monolithic brushless dc motor controller with integral high-side drive circuitry. The Si9979 is configured to allow either 60° or 120°C commutation sensor spacing. The internal low-voltage regulator allows operation over a wide input voltage range, 20- to 40-V dc.
The Si9979 provides commutation from Hall-effect sensors. The integral high-side drive, which utilizes combination bootstrap/charge pump supplies, allows implementation of an all n-channel MOSFET 3-phase bridge. PWM, direction, quadrature select, and braking inputs are included for control along with a tachometer output. Protection features include cross conduction protection, current limiting, and undervoltage lockout. The FAULT output indicates when undervoltage, over current, disable, or invalid sensor shutdown has occurred.
The Si9979 is available in both standard and lead (Pb)-free 48-pin SQFP packages and is specified to operate over the commercial temperature range of 0 to 70°C (C suffix), and the industrial temperature range of −40 to 85°C (D suffix).

FEATURES
● Hall-Effect Commutation
● 60° or 120° Sensor Spacing
● Integral High-Side Drive for all N-Channel MOSFET Bridges
● PWM Input
● Quadrature Selection
● Tachometer Output
● Reversible
● Braking
● Output Enable Control
● Cross Conduction Protection
● Current Limiting
● Undervoltage Lockout
● Internal Pull-Up Resistors