BRF1A

These quad differential receivers accept digital data over balanced transmission lines. They translate differential input logic levels to TTL output logic levels. All devices in this family have four receivers with a common enable control. These receivers are pin equivalent to the general-trade 26LS32, but offer increased speed and decreased power consumption. They replace the Agere 41 Series receivers. * This feature is available on BRF1A and BRF2A. The BRF1A device is the generic receiver in this family and requires the user to supply external resistors on the circuit board for impedance matching.

The BRF2A is identical to the BRF1A, but has an electrostatic discharge (ESD) protection circuit added to significantly improve the ESD human-body model (HBM) characteristics on the differential input terminals. The BRS2B is identical to the BRF2A, but has a preferred state feature that places the output in the high state when the inputs are open, shorted to ground, or shorted to the power supply.

The BRR1A is equivalent to the BRF1A, but has a 110 W resistor connected across the differential inputs. This eliminates the need for an external resistor when terminating a 100 W impedance line. This device is designed to work with the DP1A or PNPA in point-to-point applications.

The BRT1A is equivalent to the BRF1A; however, it is provided with a Y-type resistor network across the differential inputs and terminated to ground. The Y-type termination provides the best EMI results. This device is not recommended for applications where the differences in ground voltage between the driver and the receiver exceed 1 V. This device is designed to work with the DG1A or PNGA in point-topoint applications. The powerdown loading characteristics of the receiver input circuit are approximately 8 kW relative to the power supplies; hence, they will not load the transmission line when the circuit is powered down. For those circuits with termination resistors, the line will remain impedance matched when the circuit is powered down.

The packaging options that are available for these quad differential line drivers include a 16-pin DIP; a 16-pin, J-lead SOJ; a 16-pin, gull-wing small-outline integrated circuit (SOIC); and a 16-pin, narrow-body, gull-wing SOIC.