L9654 datasheet(45/59 Pages) STMICROELECTRONICS

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L9654

Functional description

4.13.4

Arming MISO_A bit definition

Arming MISO_A is defined in the table below.

Table 31. Arming MISO_A bit definition

ARM23

ARM01

ARM23

ARM01

4.13.5

ARM[01..23]

Arming status. These bits are used to echo arming bits sent in the previous arming

command. A value of 1 indicates that arming signal is enabled for the respective loop-pair. A

value of 0 indicates that arming signal is disabled for the respective loop-pair.

The default state of these arming signals is ‘0’ (disabled).

4.14

Satellite sensor interface

The device provides four currents limited to 60mA each through outputs ICH1 and ICH2.

The voltage at these two channels is supplied by the V8BUCK input. Channels 1 and 2

serve as switched power sources to remote mounted satellite sensors, each draws 2 current

levels. The L9654 monitors the current flow from its output pin and “demodulates” the

current to be decoded using Manchester protocol. Decoded satellite message is

communicated to an external microprocessor via SPI.

Figure 18. Satellite interface block diagram

L9654 Datasheet(PDF) 45 Page - STMicroelectronics