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

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 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).