A1374LKB datasheet(16/23 Pages) ALLEGRO

16 / 23 page

A1373-DS, Rev. 3

Worcester, Massachusetts 01615-0036 (508) 853-5000

115 Northeast Cutoff, Box 15036

www.allegromicro.com

Allegro MicroSystems, Inc.

High Precision, Output Pin Programmable, Linear Hall Effect Sensors

A1373 and A1374

The midrange voltage level, VPM, is a neutral level, used to

separate both VPH and VPL pulses from each other. The nominal

level for VPM is 15 V.

The low level, VPL, pulse is used to indicate bitfield addresses

that are to be set. The device generates an internal pulse begin-

ning at the leading (falling) edge of a VPL pulse. The duration

of the internal pulse is 5 μs. Before allowing the voltage to

rise again, an additional guard band of 1 μs is recommended to

ensure that the pulse completes, for a total of at least 6 μs after

the start of any VPL pulse. The duration of the VPL pulse, ΔtPL,

is measured from the time when the external signal voltage falls

into the range 0 to 7.5 V to the time when it rises above 10 V. If

the voltage rises above 10 V before the 5 μs period expires, then

the VPL pulse will immediately end, with undefined results. The

nominal level for VPH is 5 V.

VPL must always be maintained high enough above VR (nomi-

nally 0 V) to maintain the settings provisionally latched into

registers. Note that, when the external voltage rises from VR

through the VPL range, a spurious internal pulse is generated,

making Code 0 not available in Mode Selection state. A spurious

internal pulse also is generated when the external voltage falls

through the VPL range at the end of a code sequence. For that

reason, it is mandatory to ensure that the voltage is dropped fully

to VR, before every Blow Fuse mode operation, to ensure that

the spurious pulse does not affect the next code sequence.

A1374LKB Datasheet(PDF) 16 Page - Allegro MicroSystems