DATASHEET
ISL54103 FN6303
Rev 2.00
October 14, 2011 DDC Accelerator (DDCA)
The ISL54103 DDC Accelerator (DDCA) is a dual active pull-up
bus terminator designed to improve data transmission speed
on the DDC 2-wire serial bus interfaces.
The DDCA detects rising input transitions with two internal
voltage references and two comparators per channel. After
the voltage on a data line crosses the first threshold
(VTRIPL), the boost pull-up current source is activated to
speed transition. After the voltage crosses the second
threshold (VTRIPH), the boost pull-up current source is
de-activated, leaving an active pull-up current of 275ВµA on
the line. When both channels are HIGH, the pull-up current
for both lines is reduced to 100ВµA to save power. Internal
logic ensures that the active and boost pull-up current
sources are not activated during downward transitions.
The level for VTRIPH is controlled by a bandgap voltage
referred to VDD. This feature makes the switching behavior
invariant for all power supply voltages between 2.7V and 5.5V.
A noise filter on each channel prevents the circuit from
responding to input transitions that do not exceed a …
