ISO8200BQ datasheet(17/37 Pages) STMICROELECTRONICS

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ISO8200BQ

Functional description

DocID027303 Rev 4

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6.1.3

Output synchronization SYNC

The input is active low; it enables the ISO8200BQ transmission buffer loading input buffer

data and manages the transmission between the two isolated sides of the device.

6.1.4

Watchdog

The isolated side of the device provides a watchdog function in order to guarantee a safe

condition when Vdd supply voltage is missing.

If the logic side does not update the output status within tWD, all outputs are disabled until a

new update request is received.

The refresh signal is also considered a valid update signal, so the isolated side watchdog

does not protect the system from a failure of the host controller (MCU freezing).

Figure 7: Watchdog behavior

6.1.5

Output enable (OUT_EN)

This pin provides a fast way to disable all outputs simultaneously. When the OUT_EN pin is

driven low the outputs are disabled. To enable the output stage, the OUT_EN pin has to be

raised. This timing execution is compatible with an external reset push, safety requirement,

and allows, in a PLC system, the microcontroller polling to obtain all internal information

during a reset procedure.

Figure 8: Output channel enable timing

ISO8200BQ データシート(PDF) 17 Page - STMicroelectronics