High-Accuracy, Pulse-Width or AK Protocol

Hall-Effect Wheel Speed and Direction Sensor IC

A19302

6

Allegro MicroSystems

955 Perimeter Road

Manchester, NH 03103-3353 U.S.A.

www.allegromicro.com

OPERATING CHARACTERISTICS (continued): Valid over operating voltage and temperature, unless otherwise specified

Characteristic

Symbol

Test Conditions

Min.

Typ.[1]

Max.

Unit

THERMAL CHARACTERISTICS

Magnetic Temperature Coefficient [10]

TC

Based on ferrite ring magnet and neodymium

magnet (-xxE variant)

–

0.16

–

%/°C

Based on samarium-cobalt magnet (-xxG variant)

–

0.04

–

%/°C

Package Thermal Resistance [11]

RθJA

Single-layer PCB with copper limited to solder pads

–

213

–

°C/W

[1]

Typical values are at TA = 25°C and VCC = 12 V. Performance may vary for individual units, within the specified maximum and minimum limits.

[2]

Maximum voltage must be adjusted for power dissipation and junction temperature; refer to Power Derating section.

[3]

Negative current is defined as conventional current coming out of (sourced from) the specified device terminal.

[4]

Supply current ratio is taken as a mean value of ICC(MID) / ICC(LOW) and ICC(HIGH) / ICC(LOW).

[5]

Output transients prior to tPO should be ignored.

[6]

Differential magnetic field is measured for Channel A (E1-E2) and Channel B (E2-E3) independently. Each channel’s differential magnetic field is measured between two

Hall elements. Magnetic field is measured orthogonally to the front of the package. BDIFF(pk-pk) only valid at TA(max) due to magnetic temperature compensation. Refer to

UB package drawing.

[7]

Symmetrical signal variation is defined as the largest amplitude ratio from Bn to Bn + TWINDOW. Signal variation may occur continuously while BDIFF remains in the

operating magnetic range.

[8]

Pulse width measured at threshold of (ICC(MID) + ICC(LOW)) / 2 and (ICC(HIGH) + ICC(LOW)) / 2.

[9]

These frequency ranges are based on valid pulse width generation with each pulse width preceding with a tw(PRE)(MAX). Frequency is based on BDIFF frequency.

[10]

Magnets decrease in strength with increasing temperature. The device temperature coefficient compensates to help maintain a consistent maximum air gap over

temperature.

[11]

Additional thermal information is available on the Allegro website.