AD9398 Ver la hoja de datos (PDF) - Analog Devices
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AD9398 Datasheet PDF : 44 Pages
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DESIGN GUIDE
GENERAL DESCRIPTION
The AD9398 is a fully integrated solution for receiving
DVI/HDMI signals and is capable of decoding HDCP-
encrypted signals through connections to an external
EEPROM. The circuit is ideal for providing an interface for
HDTV monitors or as the front end to high performance video
scan converters.
Implemented in a high performance CMOS process, the
interface can capture signals with pixel rates of up to 150 MHz.
The AD9398 includes all necessary circuitry for decoding
TMDS signaling including those encrypted with HDCP.
Included in the output formatting is a color space converter
(CSC), which accommodates any input color space and can
output any color space. All controls are programmable via a 2-
wire serial interface. Full integration of these sensitive mixed
signal functions makes system design straight-forward and less
sensitive to the physical and electrical environments.
DIGITAL INPUTS
The digital control inputs (I2C) on the AD9398 operate to 3.3 V
CMOS levels. In addition, all digital inputs, except the TMDS
(HDMI/DVI) inputs, are 5 V tolerant (applying 5 V to them
does not cause damage.) The TMDS input pairs (Rx0+/Rx0−,
Rx1+/Rx1−, Rx2+/Rx2−, and RxC+/RxC−) must maintain a
100 Ω differential impedance (through proper PCB layout)
from the connector to the input where they are internally
terminated (50 Ω to 3.3 V). If additional ESD protection is
desired, use of a California Micro Devices (CMD) CM1213
(among others) series low capacitance ESD protection offers 8
kV of protection to the HDMI TMDS lines.
AD9398
SERIAL CONTROL PORT
The serial control port is designed for 3.3 V logic. However, it is
tolerant of 5 V logic signals.
OUTPUT SIGNAL HANDLING
The digital outputs operate from 1.8 V to 3.3 V (VDD).
POWER MANAGEMENT
The AD9398 uses the activity detect circuits, the active interface
bits in the serial bus, the active interface override bits, the
power-down bit, and the power-down pin to determine the
correct power state. There are four power states: full power, seek
mode, auto power-down, and power-down. Table 7 summarizes
how the AD9398 determines the power mode to use and which
circuitry is powered on/off in each of these modes. The power-
down command has priority and then the automatic circuitry.
The power-down pin (Pin 81—polarity set by Register 0x26[3])
can drive the chip into four power-down options. Bit 2 and Bit 1
of Register 0x26 control these four options. Bit 0 controls
whether the chip is powered down or the outputs are placed in
high impedance mode (with the exception of SOG). Bit 7 to
Bit 4 of Register 0x26 control whether the outputs, SOG, Sony
Philips digital interface (SPDIF ) or Inter-IC sound bus (I2S or
IIS) outputs are in high impedance mode. See the 2-Wire Serial
Control Register Detail section for the details.
Table 7. Power-Down Mode Descriptions
Inputs
Mode
Power-Down1
Sync Detect2
Full Power
1
1
Seek Mode
1
0
Seek Mode
1
0
Power-Down 0
X
Auto PD Enable3
X
0
1
Power-On or Comments
Everything
Everything
Serial bus, sync activity detect, SOG, band gap reference
Serial bus, sync activity detect, SOG, band gap reference
1 Power-down is controlled via Bit 0 in Serial Bus Register 0x26.
2 Sync detect is determined by OR’ing Bit 7 to Bit 2 in Serial Bus Register 0x15.
3 Auto power-down is controlled via Bit 7 in Serial Bus Register 0x27.
Rev. 0 | Page 9 of 44
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