These quad differential receivers accept digital data overbalanced transmission lines. They translate differential input logic levels to TTL output logic levels. The TB5R1 is a pin- and function-compatible replacement for the Agere systems BRF1A and BRF2A; it includes 3-kV HBM and 2-kV CDM ESD protection. The TB5R2 is a pin- and function-compatible replacement for the Agere systems BRS2A and BRS2B and incorporates a 125-mV receiver input offset, preferred state output, 3-kV HBM and 2-kV CDM ESD protection. The TB5R2 preferred state feature places the high state when the inputs are open, shorted to ground, or shorted to the power supply. The power-down loading characteristics of the receiver input circuit are approximately 8 k relative to the power supplies; hence they do not load the transmission line when the circuit is powered down. The packaging for these differential line receivers include a 16-pin gull wing SOIC (DW) and SOIC (D). The enable inputs of this device include internal pullup resistors of approximately 40 k that are connected to VCC to ensure a logical high level input if the inputs are open circuited.