SNLS374C – MAY 1998 – REVISED APRIL 2013
DS8921/DS8921A/DS8921AT Differential Line Driver and Receiver Pair
Check for Samples:
1
FEATURES
12 ns Typical Propagation Delay
Output Skew - 0.5 ns Typical
Meet the Requirements of EIA Standard RS-
422
Complementary Driver Outputs
High Differential or Common-Mode Input
Voltage Ranges of ±7V
±0.2V Receiver Sensitivity over the Input
Voltage Range
Receiver Input Hysteresis-70 mV Typical
DS8921AT Industrial Temperature Operation:
(−40°C to +85°C)
DESCRIPTION
The DS8921, DS8921A are Differential Line Driver
and Receiver pairs designed specifically for
applications meeting the ST506, ST412 and ESDI
Disk Drive Standards. In addition, these devices meet
the requirements of the EIA Standard RS-422.
The DS8921, DS8921A receivers offer an input
sensitivity of 200 mV over a ±7V common mode
operating range. Hysteresis is incorporated (typically
70 mV) to improve noise margin for slowly changing
input waveforms.
The DS8921, DS8921A drivers are designed to
provide unipolar differential drive to twisted pair or
parallel wire transmission lines. Complementary
outputs are logically ANDed and provide an output
skew of 0.5 ns (typ.) with propagation delays of
12 ns.
The DS8921, DS8921A are
compatible with TTL and CMOS.
designed
to
be
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Connection Diagram
DS8921/DS8921A/DS8921AT
See Package Number D (R-PDSO-G8) or P (R-PDIP-T8)
Truth Table
Receiver
Input
V
ID
≥
V
TH
(MAX)
V
ID
≤
V
TH
(MIN)
Open
V
OUT
1
0
1
Input
1
0
Driver
V
OUT
1
0
V
OUT
0
1
1
2
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Copyright © 1998–2013, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
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