SN74FB2040 Datasheet, PDF (1/9 Pages) Texas Instruments – 8-BIT TTL/BTL TRANSCEIVER

SN74FB2040
8-BIT TTL/BTL TRANSCEIVER
SCBS173N – NOVEMBER 1991 – REVISED MARCH 2002
D Compatible With IEEE Std 1194.1-1991
(BTL)
D TTL A Port, Backplane Transceiver Logic
(BTL) B Port
D Open-Collector B-Port Outputs Sink
100 mA
D High-Impedance State During Power Up
and Power Down
D BIAS V_CC Pin Minimizes Signal Distortion
During Live Insertion or Withdrawal
D B-Port Biasing Network Preconditions the
Connector and PC Trace to the BTL
High-Level Voltage
RC PACKAGE
(TOP VIEW)
GND
AI2
AI3
AO3
GND
AO4
GND
AI4
AI5
AO5
GND
AO6
GND
52 51 50 49 48 47 46 45 44 43 42 41 40
1
39
2
38
3
37
4
36
5
35
6
34
7
33
8
32
9
31
10
30
11
29
12
28
13
27
14 15 16 17 18 19 20 21 22 23 24 25 26
GND
B2
GND
B3
GND
B4
GND
B5
GND
B6
GND
B7
GND
description
The SN74FB2040 is an 8-bit transceiver designed to translate signals between TTL and backplane transceiver
logic (BTL) environments.
The B port operates at BTL-signal levels. The open-collector B ports are specified to sink 100 mA. Two output
enables (OEB and OEB) are provided for the B outputs. When OEB is high and OEB is low, the B port is active
and reflects the inverse of the data present at the A-input pins. When OEB is low, OEB is high, or V_CC is less
than 2.1 V, the B port is turned off.
The A port operates at TTL-signal levels and has separate input and output pins. The A outputs reflect the
inverse of the data at the B port when the A-port output enable (OEA) is high. When OEA is low or when V_CC
is less than 2.1 V, the A outputs are in the high-impedance state.
The pins TMS, TCK, TDI, and TDO are nonfunctional, i.e., not intended for use with the IEEE Std 1149.1 (JTAG)
test bus. TMS and TCK are not connected, and TDI is shorted to TDO.
BIAS V_CC establishes a voltage between 1.62 V and 2.1 V on the BTL outputs when V_CC is not connected.
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
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Copyright  2002, Texas Instruments Incorporated
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