Chopper-Stabilized, Precision Hall-Effect Latches

for Consumer and Industrial Applications

A3291

6

Allegro MicroSystems, LLC

115 Northeast Cutoff

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

1.508.853.5000; www.allegromicro.com

APPLICATION INFORMATION

It is strongly recommended that an external bypass capacitor be

connected (in close proximity to the Hall element) between the

supply and ground of the device to reduce both external noise

and noise generated by the chopper stabilization technique. This

configuration is shown in Figure 4.

The simplest form of magnet that will operate these devices is a

ring magnet. Other methods of operation, such as linear magnets,

are possible.

The device must be operated below the maximum junction tem-

peak conditions, reliable operation may require derating supplied

power or improving the heat dissipation properties of the applica-

summarizing the ability of the application and the device to dissi-

pate heat from the junction (die), through all paths to the ambient

air. Its primary component is the Effective Thermal Conductivity

(K) of the printed circuit board, including adjacent devices and

overmolding. Sample power dissipation results are given in the

Thermal Characteristics section. Additional thermal data is also

available on the Allegro website.

Extensive applications information for Hall-effect devices is

available in: Hall-Effect IC Applications Guide, Application Note

27701 and Guidelines for Designing Subassemblies Using Hall-

Effect Devices, Application Note 27703.1

Figure 4: Typical Basic Application Circuit

A bypass capacitor is highly recommended.

VCC

A329x

VOUT

GND

0.1 uF