Automotive Grade, 3-D Linear Hall-Effect Sensor

ALS31313

14

Allegro MicroSystems, LLC

955 Perimeter Road

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

www.allegromicro.com

PRIMARY REGISTERS

The following registers are customer accessible and may be read at any time, with or without entering the customer access code. Customer

Access mode must be enabled to write to any of these registers, with the exception of sleep, which can be written to regardless of access

mode.

Reserved

Read Only

Read/Write Volatile

Read/Write EEPROM

Write 1 to Clear

Clear on Read

Table 5: Volatile 0x27

Address

Bits

Name

Description

0x27

31:7

Reserved

Reserved

6:4

Low-Power Mode

Count Max

Sets max counter for inactive time during low-power duty cycle mode. ALS31313 offers 8 discrete

time frames for inactive time. See Application Information section on low-power modes.

3:2

section on readback modes.

1:0

Sleep

Sets device operating mode to full active, ultralow power sleep mode, or low-power duty cycle

mode. See Application Information section on low-power modes.

Table 6: Volatile 0x28

Address

Bits

Name

Description

0x28

31:24

X Axis MSBs

MSBs of the register proportional to the field strength in the X direction.

23:16

Y Axis MSBs

MSBs of the register proportional to the field strength in the Y direction.

15:8

Z Axis MSBs

MSBs of the register proportional to the field strength in the Z direction.

7

New Data

New data update flag for XYZ. Cleared when read. Set when a new update is available. Use this

bit when sampling the device faster than the update rate to avoid averaging the same sample

twice. This bit clears when address 0x28 is read.

6

Interrupt

Set when the interrupt thresholds are crossed. Latched if INT Latch Enable is set. In latched

mode, latch can be cleared by writing a 1 to this bit location.

5:0

Temperature MSBs

MSBs of the temperature register proportional to the absolute temperature.

Table 7: Volatile 0x29

Address

Bits

Name

Description

0x29

31:21

Reserved

Reserved

20

Interrupt Write

Status bit to indicate if an interrupt write is in progress. Will be set if Interrupt EEPROM Enable

is set and an interrupt event has occurred. This field will be set while the device is writing the

Interrupt EEPROM Status bit in address 0x03. When the writing is complete, this bit will clear

automatically.

19:16

X Axis LSBs

LSBs of the register proportional to the field-strength in the X direction.

15:12

Y Axis LSBs

LSBs of the register proportional to the field-strength in the Y direction.

11:8

Z Axis LSBs

LSBs of the register proportional to the field-strength in the Z direction.

7:6

Hall Mode Status

The Hall mode of the current readout. Will be primarily used if 0x02 Hall mode is set to

alternating mode. See Application Information section on Hall modes.

0 = Value measured in Single-Ended Hall Mode

1 = Value measured in Differential Hall Mode

2 = Value measured in Common Hall Mode

5:0

Temperature LSBs

LSBs of the temperature register proportional to the absolute temperature.