A5947-B
Three-Phase Sensorless Fan Driver IC
FEATURES AND BENEFITS
• AEC-Q100 qualified
• Speed curve configuration via EEPROM
• I2C serial port
• Sinusoidal modulation for reduced audible noise and
low vibration
• Sensorless (no Hall sensors required)
• Low RDS(ON) power MOSFETs
• 3.3 V / 20 mA linear regulator
• PWM or analog speed input
• FG speed output
• Slew rate control
• Lock detection
• Soft start
• Low power standby mode
• Overcurrent protection
• Overvoltage protection
PACKAGE:
Not to scale
DESCRIPTION
The A5947-B three phase motor driver IC incorporates
sensorless sinusoidal drive to minimize vibration for a wide
variety of fan applications. Sensorless control eliminates the
requirement for Hall sensors.
A flexible closed-loop speed control system is integrated into
the IC. EEPROM is used to tailor the common functions of the
fan speed curve to a specific application. This eliminates the
requirement for a microprocessor-based system and minimizes
programming requirements.
The A5947-B is available in a 20-lead TSSOP with exposed
thermal pad (suffix LP).
20-lead TSSOP
with exposed thermal pad
(LP package)
0.1 µF / X7R
0.22 µF / X7R
A5947
VREF
nFAULT
VREF
Charge Pump
10 kΩ
Duty In
TEST
SPD
FG
GND
Control Logic
6
GATE
DRIVE
Speed
Control
Loop
System
Variables
DATA
CLK
EEPROM
Current
Limit
Posi�on
Measure
OUTA
OUTB
OUTC
A5947-B-DS, Rev. 2
MCO-0001086
Figure 1: Typical Application
VCP
VBB
0.1 µF / X7R
+12 VIN
22 µF
OUTA
OUTB
OUTC
LSS
April 7, 2022
