DC906A

DC906A demonstration circuit features the LTC®4306IUFD, a 4-channel, 2-wire I2C bus and SMBus compatible multiplexer having bus buffers that provide capacitive isolation between the upstream bus and downstream buses. Through software control, the LTC4306IUFD connects the upstream 2-wire bus to any desired combination of downstream buses. Each bus can be pulled up to a supply voltage ranging from 2.2V to 5.5V, independent of the LTC4306IUFD supply voltage. The downstream buses are also provided with ALERT1B – ALERT4B inputs for fault reporting. Programmable timeout circuitry disconnects the downstream buses if the bus is stuck low. When activated, rise time accelerators source currents into the 2-wire bus pins during rising edges to reduce rise time. Two general purpose input/output (GPIO) pins can be configured as inputs, open-drain outputs or push-pull outputs. Green LED’s D3 and D2 light up when GPIO1 and GPIO2, respectively, are low.

• 2.7V to 5.5V VCC voltage operating range
• 2.2V to 5.5V bus pull-up supply voltage range (VBUS1-VBUS4 )
• 0 - 400kHz 2-wire bus frequency range
• 100mV (maximum) bus buffer VOL offset voltage at RBUS = 10K
• 5.5mA (typical) rise time accelerator pull-up current at VCC = 3.3V
• 0.4V (maximum) ALERTB and READY output VOL voltages at VCC = 2.7V - 5.5V, IALERTB = IREADY = 3mA