Functional description

ISO8200B

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Doc ID 023802 Rev 1

6

Functional description

6.1

Parallel interface

The Smart parallel interface built into the ISO8200B offers three interfacing signals, which

are easily manageable from a microcontroller.

The LOAD signal enables the input buffer to store the value of the channel inputs.

The SYNC signal copies the input buffer value into the transmission buffer and manages the

synchronization between the low voltage side and the channel outputs on the isolated side.

The OUT_EN signal enables the channel outputs.

frequency. This signal can be disabled forcing low the SYNC input when LOAD is high.

Managing SYNC and LOAD pins in direct control mode (DCM) or synchronous control mode

(SCM) can be implemented.

The operation of these two signals is described by the following table:

6.1.1

Input signals (IN1 to IN8)

Inputs from IN1 to IN8 are the driving signals of the corresponding OUT1 to OUT8 outputs.

The present data are directly loaded on related outputs if SYNC and LOAD inputs are low

(DCM operation) or stored into input buffer when LOAD is low and SYNC is high.

6.1.2

Load input data (LOAD)

The input is active low; it stores the present data of IN1 to IN8 into the input buffer.

Table 13.

Interface signal operation (general)

LOAD

SYNC

OUT_EN

Device behavior

Don’t care

Don’t care

1.

The outputs are turned off on OUT_EN falling edge and they are kept disabled as long as it is low.

The outputs are disabled (turned off).

High

High

High

The outputs are left unchanged.

Low

High

High

The input buffer is enabled.

The outputs are left unchanged.

High

Low

High

The internal refresh signal is disabled.

The transmission buffer is updated.

The outputs are left unchanged.

Don’t care

High

The outputs are updated according to current

transmission buffer value.

Low

Low

High

The device operates in direct control mode as

described in the respective paragraph.