DS28EC20

Analog Devices, Inc.

23 of 28

Controller-to-Peripheral

For a write-one time slot, the voltage on the data line must have crossed the VTH threshold before the write-one low

time tW1LMAX is expired. For a write-zero time slot, the voltage on the data line must stay below the VTH threshold

until the write-zero low time tW0LMIN is expired. For the most reliable communication, the voltage on the data line

should not exceed VILMAX during the entire tW0L or tW1L window. After the VTH threshold has been crossed, the

DS28EC20 needs a recovery time tREC before it is ready for the next time slot.

Figure 11. Read/Write Timing Diagram

Write-One Time Slot

RESISTOR

CONTROLLER

VPUP

VIHCONTROLLER

VTH

VTL

VILMAX

0V

tF

tSLOT

tW1L

ε

Write-Zero Time Slot

RESISTOR

CONTROLLER

tREC

VPUP

VIHCONTROLLER

VTH

VTL

VILMAX

0V

tF

tSLOT

tW0L

ε

Read-Data Time Slot

RESISTOR

CONTROLLER

DS28EC20

tREC

VPUP

VIHCONTROLLER

VTH

VTL

VILMAX

0V

Controller

Sampling

Window

δ

tF

tSLOT

tRL

tMSR