L9678P datasheet(136/203 Pages) STMICROELECTRONICS

No. de pieza	L9678P

Descripción Electrónicos	Automotive user configurable airbag IC

PDF	203 Pages

Scroll/Zoom	100%

Fabricante Electrónico	STMICROELECTRONICS [STMicroelectronics]

Página de inicio	http://www.st.com

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136 / 203 page

DC sensor interface

L9678P, L9678P-S

136/203

DocID029274 Rev 3

DC sensor interface

L9678P 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: 2 mA to 20 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 38. Switch 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 setting CHID bits accordingly. The interface activation is completely controlled by

user SPI command. The interface could be optionally configured for "automatic switch-off"

immediately after the current or resistance measurement completion by setting the

EN_AUTO_SWITCH_OFF bit in the SYS_CFG register.

L9678P Datasheet(PDF) 136 Page - STMicroelectronics