特点
Precision Propagation Delay Over Temperature: Receiver/Driver: 18.5ns ?3.5ns
High Data Rate: 52Mbps
Low tPLH/tPLH Skew: Receiver/Driver: 500ps Typ
?7V to 12V RS485 Input Common Mode Range
Guaranteed Fail-Safe Operation Over the Entire Common Mode Range
High Input Resistance: ?22k, Even When Unpowered
Short-Circuit Protected
Thermal Shutdown Protected
Driver Maintains High Impedance in Three-State or with Power Off
Single 5V Supply
Pin Compatible with LTC490/LTC491
45dB CMRR at 26MHz
典型应用
典型应用
描述
描述 The LTC?1686/LTC1687 are high speed, precision delay, full-duplex RS485 transceivers that can operate at data rates as high as 52Mbps. The devices also meet the requirements of RS422. A unique architecture provides very stable propagation delays and low skew over a wide common mode and ambient temperature range. The driver and receiver feature three-state outputs, with disabled driver outputs maintaining high impedance over the entire common mode range. A short-circuit feature detects shorted outputs and substantially reduces driver output current. A similar feature also protects the receiver output from short circuits. Thermal shutdown circuitry protects from excessive power dissipation. The receiver has a fail-safe feature that guarantees a high output state when the inputs are shorted or are left floating. The LTC1686/LTC1687 RS485 transceivers guarantee receiver fail-safe operation over the entire common mode range (?7V to 12V). Receiver input resistance remains ?22k when the device is unpowered or disabled. The LTC1686/LTC1687 operate from a single 5V supply and draw only 7mA of supply current.