LTC4300A-1
Linear Technology
The LTC4300A-1 is a 2-wire bus buffer that includes capacitance buffering between input and output
Design DocumentAnalog
Design Note 394: Pass HDMI Compliance Tests with Ease using LTC4300A
Learn how LTC4300A-1 and LTC4300A-3 bus buffers enable HDMI devices to meet 50pF DDC input capacitance limits and improve I2C rise times on high-load cables.
Overview
This design note details the use of LTC4300A-1 and LTC4300A-3 2-wire bus buffers to achieve HDMI compliance for the Display Data Channel (DDC). The HDMI specification requires input capacitance below 50pF, which these buffers facilitate by providing sub-10pF input capacitance and isolation from internal bus loads. The LTC4300A-1 includes rise time accelerators to maintain 100kHz I2C timing requirements even with cable loads exceeding 800pF. The LTC4300A-3 variant supports level shifting between 5V and 3.3V segments, allowing EDID EEPROMs to remain accessible during power-off states via backup supplies. These solutions also provide enhanced ESD protection and support hot plug detect (HPD) signaling.
Use Cases
- HDMI sink devices like digital TVs
- HDMI source devices like DVD players
- HDMI repeaters and digital receivers
- I2C bus capacitance isolation
- 5V to 3.3V level shifting for HDMI DDC
Topics
HDMI compliance
DDC bus
I2C buffer
capacitance buffering
LTC4300A-1
LTC4300A-3
EDID
rise time accelerator
level shifting
hot plug detect
Referenced Parts
LTC4300A-3
Linear Technology
The LTC4300A-3 level shifting I 2 C buffer is also a good solution for this application.
| LTC4300A-1 | Linear Technology | The LTC4300A-1 is a 2-wire bus buffer that includes capacitance buffering between input and output |
| LTC4300A-3 | Linear Technology | The LTC4300A-3 level shifting I 2 C buffer is also a good solution for this application. |