??? 12/14/07 09:31 Read: times |
#148200 - more clarification! Responding to: ???'s previous message |
one wire communication,with 0-12 volt voltage level.
question:how to design this scheme to have this I/O specifications: 1-In "Power Off" state, in the receiving state and at logic "1" in the transmitting state, TX_RX of the device shall behave like a resistance to ground of 120 kohms ± 5 %. No internal resistance between TX_RX and VCC shall be used. The capacitance of TX_RX with respect to ground of each device should not exceed 250 pF. 2-At logic "0", in the transmitting state, the device shall have an equivalent sink resistance of not more than 110 ohm between TX_RX and ground. 3-When the power supply of the device is switched on or off, the device shall not produce any signals or other disturbances on the TX_RX. |