Data Sheet

April 2001

Quad Differential Receivers

BRF1A, BRF2A, BRS2B, BRR1A, and BRT1A

Features

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Pin equivalent to the general-trade 26LS32 device,

with improved speed, reduced power consumption,

and significantly lower levels of EMI

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High input impedance approximately 8 k

Ω

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Four line receivers per package

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400 Mbits/s maximum data rate when used with

Agere Systems Inc. data transmission drivers

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Meets enhanced small device interface (ESDI)

standards

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4.0 ns maximum propagation delay

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<0.20 V input sensitivity

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−1.2 V to +7.2 V common-mode range

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−40 °C to +125 °C ambient operating temperature

range (wider than the 41 Series)

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Single 5.0 V

± 10% supply

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Output defaults to logic 1 when inputs are left

open*

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Available in four package types

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Lower power requirement than the 41 Series

Description

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

Ω resistor connected across the differential

inputs. This eliminates the need for an external

resistor when terminating a 100

Ω 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-to-

point applications.

The powerdown loading characteristics of the

receiver input circuit are approximately 8 k

Ω 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.