LTC4307-1 Datasheet, PDF (1/12 Pages) Linear Technology – High Defi nition Multimedia Interface (HDMI) Level- Shifting 2-Wire Bus Buffer

LTC4307-1
High Definition Multimedia
Interface (HDMI) Level-
Shifting 2-Wire Bus Buffer
FEATURES
■ _{Bidirectional Buffer for Display Data Channel (DDC)}
■ _{Compliant with HDMI Specification Version 1.3}
DDC Capacitance Requirement
■ _{Level Translation Between 3.3V and 5V}
■ _{±5kV Human Body Model ESD Protection}
■ _{60mV Buffer Offset Independent of Load}
■ _{Compatible with Non-Compliant VOL I}²_{C Devices}
■ _{Isolates Input SDA and SCL Line from Output}
■ _{Compatible with I}²_C^TM_{, I}²_{C Fast Mode and SMBus}
■ _{READY Open-Drain Output}
■ _{High Impedance SDA, SCL Pins for VCC = 0V}
■ _{Small 8-Lead (3mm × 3mm) DFN and 8-Lead MSOP}
Packages
U
APPLICATIO S
■ _HDMI
■ _{3.3V/5V Level Translation}
■ _{Capacitance Buffer/Bus Extender}
DESCRIPTIO
The LTC4307-1 is a 2-wire bus buffer that provides ca-
pacitance buffering between input and output. The HDMI
specification requires that devices have less than 50pF of
input capacitance on their DDC bus lines. The LTC4307-1’s
capacitance buffering feature, in conjunction with its
sub-10pF data and clock input capacitance, allows HDMI
components to easily meet the 50pF requirement and
tolerate high capacitance on the internal bus.
The LTC4307-1 also provides level-shifting between 3.3V
and 5V systems to allow lower voltage HDMI transmitters,
receivers and EEPROM to interface to the 5V DDC bus.
READY is an open-drain digital output flag that indicates
whether or not the input and output busses are connected
and can interface to the HDMI hot plug detect (HPD) signal.
When driven high, the ENABLE digital input allows the
LTC4307-1 to connect after a stop bit or bus idle. Driving
ENABLE low breaks the connection between the input and
output busses.
, LT, LTC and LTM are registered trademarks of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
Protected by U.S. Patents, including 7032051, 6356140, 6650174
TYPICAL APPLICATIO
DVD PLAYER (SOURCE)
TV (SINK)
HDMI TX
IC
5V
1.8k 1.8k
EEPROM
HDMI
CABLE
<50pF
DDC GROUND
3.3V
0.1μF
LTC4307-1
V_CC
SDAIN SDAOUT
SCLIN SCLOUT
ENABLE
GND
10k 10k
HDMI RX
IC
μC
43071 TA01a
Rising Edge from Asserted Low
1000
800
600
LOW
OFFSET
400
SDAOUT
SDAIN
200
0
0 100 200 300 400 500 600
100ns/DIV
43071 TA01b
43071fa
1