The LTC4307 is a low offset hot swappable 2-wire bus buffer that allows I/O card insertion into a live backplane without corruption of the data and clock busses. It provides bidirectional buffering, keeping the backplane and card capacitances isolated. The LTC4307 has low offset and high VOL tolerance, allowing multiple devices to be cascaded on the clock and data busses. If SDAOUT or SCLOUT are low for 30ms, the LTC4307 will automatically break the bus connection and generate clock pulses to attempt to free the bus. The connection will resume if the stuck bus is cleared. During insertion, the SDA and SCL lines are pre-charged to 1V to minimize bus disturbances. The ENABLE input allows the LTC4307 to connect after a stop bit or bus idle. Driving ENABLE low breaks the connection between SDAIN and SDAOUT, SCLIN and SCLOUT. The READY output indicates that the backplane and card sides are connected.
The LTC4307 hot‑swappable, 2‑wire bus buffer enables live backplane insertion without corrupting data or clock lines. It provides bidirectional buffering, isolates backplane and card capacitances, and automatically disconnects the bus if a stuck‑low condition persists for 30 ms, then attempts recovery with up to 16 clock pulses.
The device operates from a 3.3 V supply, supports +5 kV HBM ESD protection, and is offered in compact 8‑lead DFN (3 mm × 3 mm) and 8‑lead MSOP packages. Detailed electrical characteristics, pin functions, timing diagrams, and typical application circuits are included.
| Stuck Bus Timeout | 30 ms |
|---|---|
| Operating Temperature Range | -65 °C to 125 °C |
| Supply Voltage (Vcc) | 3.3 V (typical) |
| ESD Protection | +5 kV Human Body Model |
The device operates from a 3.3 V supply (Voc = 3.3 V typical).
The LTC4307 is offered in an 8‑lead DFN (3 mm × 3 mm) and an 8‑lead MSOP package.