FS6407 datasheet(25/111 Pages) NXP

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NXP Semiconductors

FS6407/FS6408

Figure 7. Simplified analog multiplexer block diagram

5.13

I/O pins (I/O_0:I/O_5)

The FS6407/FS6408 includes six multi-purpose I/Os (I/O_0 to I/O_5). I/O_0, I/O_1, I/O_4, and I/O_5 are robust against ISO7637 pulses.

An external serial resistor must be connected to those pins to limit the current during ISO pulses.

• IO_0:1 are selectable as follows:

Analog input (load dump proof) sent to the MCU through the MUX_OUT pin. Wake-up input on the rising or falling edge or based on

the previous state. Digital input (logic level) sent to the MCU through the SPI. Safety purpose: Digital input (logic level) to perform

an IC error monitoring (both IO_0 AND IO_1 are used if configured as safety inputs, see Figure 9).

• IO_1 is also selectable as follow:

Safety purpose: FB_Core using a second resistor bridge (R3/R4 duplicated) connected to IO_1, to detect external resistor drift and

trigger when FB_Core - IO_1 >

±150 mV max.

• IO_2:3 are selectable as follows:

Digital input (logic level) sent to the MCU through the SPI. Wake-up input (logic level) on the rising or falling edge or based on the

previous state. Safety purpose: Digital input (logic level) to monitor MCU error signals (both IO_2 AND IO_3 are used if configured

as safety inputs). Only bi-stable protocol is available.

When IO_2:3 are used as safety inputs to monitor FCCU error outputs from the NXP MCU, the monitoring is active only when the

Fail-safe sate machine is in “normal WD running” state (Figure 11) and all the phases except the “Normal Phase” are considered as

an Error.

Table 8. I/Os configuration

I/0 number

Digital input

Wake-up capability

Output gate driver

IO_0

IO_1

IO_2

IO_3

IO_4

IO_5

SPI selection

Internal 2.5V reference

Mux_out

SPI selection

Die temperature sensor

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