MLX90805 ETC [List of Unclassifed Manufacturers], MLX90805 Datasheet - Page 10

• Manufacturer Part Number: MLX90805
• Description: Intelligent Triac Controller
• Manufacturer: ETC [List of Unclassifed Manufacturers]

Soft Start With 3-Wire Setting
The speed control is performed in addition to the soft
start in this application. A potentiometer in 3-wire
connection is used to define different speed settings.
The input signal for the ADC varies between 0 and
VREF.
The minimum speed corresponds to a maximum volt-
age at SET. Maximum speed corresponds to a mini-
mum voltage at SET. When the mains voltage is ap-
plied to the system, the motor starts running at a
speed defined by the potentiometer, as soon as the
soft start time has finished.
The voltage at SET is transferred to a 4 bit value to
address a ROM table in which the different phase
angles are defined with a 10 bit resolution.
The 3-wire mode is selected by connecting VFB to
VSS (eventually via a resistor).
MLX90805 Intelligent Triac Controller
Applications Example - Soft Start with 3-Wire Setting
N
L
Cf
R Z
R M
Vdda
Vss
Z C
T H P
Page 10
R2
Note:
R1, R2 and NTC are only needed for thermal pro-
tection, and can be left out otherwise
N T C
90805
Vref
Intelligent Triac Controller
S E T
Pot
T R G
R1
FB
MLX90805
Rev 1.2 17/May/00
M