ATS635LSE and ATS636LSE

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

Page 8 of 15

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Copyright © 2005 Allegro MicroSystems, Inc.

Program Enable.

To program the device, a keying sequence is used to activate / enable the programming mode as

no supply interruptions. The sequence is designed to prevent the device from being programmed accidentally (e.g., as a

result of noise on the supply line).

0

t

d(1)

t

d(1)

t

d(0)

PROGRAM ENABLE

7 or More Pulses

(8 Pulses Shown)

V

PL

V

PH

V

PP

Figure 4 – Program Enable Pulse Sequence

Code Programming.

After the desired switch point code is selected (0 through 127), each bit of the corresponding binary

address should be programmed individually, not at the same time. For example, to program code 5 (binary 000101), bits

programming is not reversible. An appropriate sequence for blowing code 5 is shown in Figure 5.

Figure 5 – Code Programming Example

Polarity Bit Programming.

If the desired switchpoint has negative polarity, the polarity bit must be programmed. To do

programming range only and will not affect the output polarity. The proper output polarity device is determined by

ordering the correct part number (ATS635 or ATS636), as they are different ICs.

V

PH

V

PP

Program Enable

0

V

PL

t

d(1)

t

d(1)

t

d(0)

t

dP

Figure 6 – Polarity Bit Programming

V

PH

V

PP

Program Enable

Bit 3 Address

000100

Code 4

Program Enable

0

V

PL

t

d(1)

t

d(1)

t

d(0)

t

dP

000001

Code 1