ACS108-5Sx

3/8

®

AC LINE SWITCH BASIC APPLICATION

The ACS108 device is well adapted to washing machines, dishwashers, tumble driers, refrigerators, water

heaters and cookware. It has been especially designed to switch ON and OFF low power loads such as

solenoids, valves, relays, dispensers, micro-motors, fans, pumps, door locks and low power lamp bulbs.

Pin COM

: Common drive reference to connect to the power line neutral

Pin G

: Switch Gate input to connect to the digital controller through the resistor

Pin OUT

: Switch Output to connect to the load

This ACS™ switch is triggered with a negative gate current flowing out of the gate pin G. It can be driven

directly by the digital controller through a resistor as shown on the typical application diagram. No protec-

tion devices are required between the gates and common terminals.

The SOT-223 version allows several ACS108 devices to be connected on the same cooling PCB pad

which is the COM pin : this cooling pad can be then reduced, and the printed circuit layout is simplified.

In appliance systems, the ACS108 switch intends to drive low power load in full cycle ON/OFF mode. The

turn off commutation characteristics of these loads can be classified in 3 groups as shown in Table 1.

Thanks to its thermal and turn-off commutation characteristics, the ACS108 switch drives a load, such as

door lock, lamp, relay, valve and micro motor, up to 0.2 A without any turn-off aid circuit. Switching off the

ACS within one full AC line cycle will extend its current up to 0.8 A on resistive load.

Table 1: Load grouping versus their turn off commutation requirement (230V AC applications).

TYPICAL APPLICATION DIAGRAM

LOAD

Load IRMS

current

POWER

FACTOR

(dI/dt)c

(dV/dt)c

TURN-OFF

DELAY

(A)

(A/ms)

(V/µs)

(ms)

Door lock, lamp

< 0.3

1

0.15

0.15

< 10

< 0.8

1

0.4

0.15

< 20

Relay Valve

Dispenser

Micro-motor

< 0.1

> 0.7

< 0.05

< 5

< 10

Pump Fan

< 0.2

> 0.2

< 0.1

< 10

< 10

< 0.6

> 0.2

< 0.3

< 10

< 20

AC

MAINS

L

N

ST 72 MCU

LOAD

-Vcc

L

R

G

COM

OUT

ACS108

ON

S

D