Data Sheet
April 2001
Quad Differential Receivers
BRF1A, BRF2A, BRS2B, BRR1A, and BRT1A
Features
a73 Pin equivalent to the general-trade 26LS32 device,
with improved speed, reduced power consumption,
and significantly lower levels of EMI
a73 High input impedance approximately 8 kΩ
a73 Four line receivers per package
a73 400 Mbits/s maximum data rate when used with
Agere Systems Inc. data transmission drivers
a73 Meets enhanced small device interface (ESDI)
standards
a73 4.0 ns maximum propagation delay
a73 <0.20 V input sensitivity
a73 −1.2 V to +7.2 V common-mode range
a73 −40 °C to +125 °C ambient operating temperature
range (wider than the 41 Series)
a73 Single 5.0 V ± 10% supply
a73 Output defaults to logic 1 when inputs are left
open*
a73 Available in four package types
a73 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 kΩ 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.