L9679P datasheet(186/272 Pages) STMICROELECTRONICS

186 / 272 page

DC sensor interface

L9679P

186/272

DocID029275 Rev 1

DC sensor interface

L9679P implements a circuitry able to interface with a variety of positioning sensors. The

sensors that can be connected to the device are Hall-effect, resistive or simple switches.

Range of measurements is:



Resistive sensor: 65 Ω

to 3 kΩ



Hall-effect sensor: 1 mA to 2 0 mA.

Within the above ranges, accuracy of ±15% is granted. A reduced accuracy is given in the

range 1 mA to 2 mA. Hall sensor and switch interface block diagram is shown below.

Figure 47. DC sensor interface block diagram

The global SPI contains several bits to control and configure the interface. The SWOEN bit

is used to enable the output voltage on DCSx pins. The channel to be activated can be

chosen by accordingly setting CHID bits. The interface activation is started and switched off

upon user SPI command. Alternatively it could be configured via the

SYS_CFG(EN_AUTO_SWITCH_OFF) bit to automatically switch off as soon as the

measurement is complete, in case of current or resistance measurements; this would help

preventing thermal conditions. The interface would not auto-switched off in case of voltage

measurement, instead.

L9679P 数据表(PDF) 186 Page - STMicroelectronics