ATS636LSE datasheet(7/15 Pages) ALLEGRO

7 / 15 page

ATS635LSE and ATS636LSE

PROGRAMMABLE TRUE POWER-ON HALL-EFFECT GEAR-TOOTH SWITCHES

Page 7 of 15

115 Northeast Cutoff, Box 15036

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

FUNCTION DESCRIPTION: ADDRESSING / PROGRAMMING PROTOCOL

The ATS635LSE and ATS636LSE magnetic operate point (BOP) is programmed by serially addressing the devices

through the supply terminal (1). After the correct operate point is determined, the device programming bits are selected

and blown, then a lock bit is selected and blown to prevent any further (accidental) programming.

Addressing:

Bop is programmable in both the positive and negative direction from its initial value. Addressing is used to

determine the desired code, while programming is used to lock the code. A unique key is needed to blow fuses, while

addressing as described below does not allow for the device to be programmed accidentally.

Addressing with positive polarity.

The magnetic operate point (BOP) is adjustable using 7 bits or 128 addresses. The

Addresses are sequentially selected (Figure 2) until the required operate point is reached. The first address must be

selected with a High voltage pulse (VPP), while the remaining pulses should be VPH Pulses. Note that the difference

between BOP and the magnetic release point (BRP), the Hysteresis (BHYS), is fixed for all addresses.

td(1)

td(0)

Figure 2 – Addressing Pulses: Positive Polarity

Addressing with negative polarity.

The magnetic operate point (BOP) is adjustable with negative polarity using 7 bits or

128 addresses. To invert the polarity it is necessary to first apply a keying sequence (Figure 3). Th e polarity key contains

a VPP pulse and at least 1 VPH pulse, but no more than 6 VPH pulses; the key in Figure 3 shows 2 VPH pulses. The

addresses are then sequentially selected until the required operate point is reached. The first address must be selected

with a High voltage pulse (VPP), while the remaining pulses should be VPH Pulses.

td(1)

td(0)

Figure 3 – Addressing Pulses: Negative Polarity

ATS636LSE Datasheet(PDF) 7 Page - Allegro MicroSystems