SPEC-1654 (REV. 4)

13/18

29-09-2017

SA4104A / SA4104B

Direction Indicator Output (DIRO)

The direction of the energy flow may be ascertained by

monitoring the DIRO pin. A low level on this pin indicates

negative energy flow. Positive energy flow is indicated by a

high level. Should the energy (either negative or positive) be

less than the anti-creep threshold then this output will retain

its previous state. This prevents a flickering output in the case

of no or very low current flow. The DIRO pin may be used to

drive an LED. The state of the DIRO pin is updated on the

internal FAST mode pulses, regardless of whether the device

is set to FAST or STANDARD mode. A power-on reset will

set DIRO high and it will remain high until negative energy

above the anti-creep threshold is detected. Table 4 illustrates

the operation of the DIRO output.

Table 4: Operation of the DIRO output

Energy Level

|Phase Angle|

State of DIRO

0º - 360º

Previous State

< 90º

HIGH

> 90º

LOW