Dual Channel Switch Interface IC

A6850

11

Allegro MicroSystems, Inc.

115 Northeast Cutoff

Worcester, Massachusetts 01615-0036 U.S.A.

1.508.853.5000; www.allegromicro.com

Protection from EMI

Transients generated by electromagnetic interference (EMI)

can disturb operation of the A6850 or add unwanted noise to the

signals being processed.

The scheme shown in figure 9 illustrates possible supply decou-

pling and signal filtering options. The selection of protection and

filtering component values will depend on the details of the final

application.

The A6850 must be protected with a suitable bypass capacitor to

prevent transients entering VIN. The capacitor should be as close

to the VIN and GND pins as feasible.

A pi-filter placed between the OUTPUTx pins and the sensor IC

has been shown to demonstrate excellent performance in nor-

mal automotive Bulk Cable Injection (BCI) testing. However,

component selection and layout as well as cable specification and

placement must be tailored to the individual application. EMC

results should be validated.

0.1 μF

1000 pF

1 μF

100 Ω

VIN

VBAT

GROUND

A6850

Hall

Device

OUTPUT1

OUTPUT2

1

2

SENSE2

SENSE1

ENABLE2

ENABLE1

Figure 9. Decoupling and filtering suggestions