STDVE003A_08 STMICROELECTRONICS [STMicroelectronics], STDVE003A_08 Datasheet - Page 14

• Manufacturer Part Number: STDVE003A_08
• Description: Adaptive 3.4 Gbps 3:1 TMDS/HDMI signal equalizer
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

Functional description
3.5
3.6
3.7
14/41
I
The device contains two identical bidirectional open-drain, non-inverting buffer circuits that
enable I
STDVE003A buffers both the serial data (DDC SDA) and serial clock (DDC SCL) on the I2C
bus, while retaining all the operating modes and features of the I
two buses of 400 pF bus capacitance to be connected in an I
are operational from a supply V of 3.0 V to 3.6 V.
The I
STDVE003A enables the system designer to isolate the two halves of a bus,
accommodating more I
buses, one at 5 V and the other at 3.3 V or a 400 kHz and 100 kHz bus, where the 100 kHz
bus is isolated when 400 kHz operation of the other bus is required. The STDVE003A can
be used to run the I
The S1, S2 and S3 (SEL) lines act as control signals for the corresponding A, B or C ports.
Note that the SEL line has an internal pull-down resistor. The SEL line should not change
state during an I
enabling part way through a bus cycle could confuse the I
input should change state only when the global bus and the repeater port are in idle state, to
prevent system failures.
The output low levels for each internal buffer are approximately 0.5 V, but the input voltage
of each internal buffer must be 70 mV or more below the output low level, when the output
internally is driven low. This prevents a lock-up condition from occurring when the input low
condition is released.
As with the standard I
levels on the buffered bus. The STDVE003A has standard open collector configuration of
the I
repeater must have a pull up resistor.
This part is designed to work with standard mode and fast mode I
mode I
in a generic I
Under certain conditions, higher termination currents can be used.
Power-down condition
The SEL line has an internal pull-down resistor which prevents it from going into an
unknown state in the absence of supply to STDVE003A. Also there is no ESD protection
diode to supply on any of the IOs. This prevents a reverse current flow condition when the
main box is switched off while the TV is switched on.
The OE_N is used to disable most of the internal circuitry of STDVE003A that puts the
device in a low power mode of operation.
Bias
The bandgap reference voltage over the external R
bias reference current. This current and its factors (achieved by employing highly accurate
and well matched current mirror circuit topologies) are generated on-chip and used by
2
C DDC line repeater
2
2
C bus. The size of the pull up resistors depends on the system, but each side of the
C bus capacitance limit of 400 pF restricts the number of devices and bus length. The
2
C devices only specify 3 mA output drive, this limits the termination current to 3 mA
2
C DDC bus lines to be extended without degradation in system performance. The
2
C system where standard mode devices and multiple masters are possible.
2
C operation, because disabling during bus operation hangs the bus and
2
C bus at both 5 V and 3.3 V interface levels.
2
C system, pull up resistors are required to provide the logic high
2
C devices or longer trace lengths. It can also be used to run two
EXT
reference resistor sets the internal
2
C parts being enabled. The SEL
2
C application. These buffers
2
C system. This enables
2
C devices. Standard
STDVE003A