1 Features

• Three-phase BLDC motor driver with integrated

sensorless motor control algorithm

– Code-free high speed Trapezoidal Control

– Supports up to 3 kHz (electrical frequency)

– Very fast start-up time (< 50 ms)

– Fast Deceleration (< 150 ms)

– Supports 120° or 150° modulation to improve

acoustic performance

– Closed loop speed or power control

– Configurable profiles for speed or power input

reference

– Windmilling support through forward

resynchronization and reverse drive

– Analog, PWM, freq. or I2C based speed input

– Configurable motor start-up and stop options

– Anti-voltage surge (AVS) protection prevents

DC bus voltage spike during motor deceleration

– Variable monitoring through DACOUT

• 4.5- to 20-V operating voltage (24-V abs max)

• High output current capability: 5-A peak

• Low MOSFET on-state resistance

– RDS(ON) (HS + LS) at TA = 25°C : 130-mΩ

• Low power sleep mode

– 7-μA (maximum) at VVM = 12-V, TA = 25°C

• Speed loop accuracy: 3 with internal clock and

1 with external clock reference

• Supports up to 100-kHz PWM frequency for low

inductance motor support

• Does not require external current sense resistor

• Built-in 3.3-V ±5, 20-mA LDO regulator

• Spread spectrum and slew rate for EMI mitigation

• Suite of Integrated protection features

– Supply under voltage lockout (UVLO)

– Motor lock detection (5 different types)

– Over current protection (OCP)

– Over temperature warning and shutdown

(OTW/OTS)

– Fault condition indication pin (nFAULT)

– Optional fault diagnostics over I2C interface

2 Applications

• Brushless-DC (BLDC) Motor Modules

• Robotic Vacuum Suction Motors

• Server Fans

• Appliance Fans and Pumps

3 Description

The MCT8317A provides a single-chip, codefree

sensorless trapezoidal solution for customers

requiring high speed operation (up to 3 kHz electrical)

or very fast start-up time (< 50 ms) for 12-V

brushless-DC motors up to 5-A peak current. The

MCT8317A integrates three ½-bridges with 24-V

absolute maximum capability and a very low RDS(ON)

of 130 mΩ (high-side + low-side FETs). MCT8317A

also features an LDO that generates a 3.3-V voltage

rail and can source up to 20 mA to power external

circuits.

Sensorless trapezoidal control is highly configurable

through register settings ranging from motor start-up

behavior to closed loop operation. Register settings

for MCT8317A can be set in non-volatile EEPROM,

which allows the device to operate stand-alone once

it has been configured. The device receives a speed

command through a PWM input, analog voltage,

variable frequency square wave or I2C command.

There are a large number of protection features

integrated into the MCT8317A, intended to protect the

device, motor, and system against fault events.