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4-273
FAST AND LS TTL DATA
QUAD FUTUREBUS
BACKPLANE TRANSCEIVER
(3 STATE + OPEN COLLECTOR)
The MC74F3893A is a quad backplane transceiver and is intended to be
used in very high speed bus systems.
The MC74F3893A interfaces to “Backplane Transceiver Logic” (BTL). BTL
features a reduced (1 V) voltage swing for lower power consumption and a se-
ries diode on the drivers to reduce capacitive loading (< 5 pF).
Incident wave switching is employed, therefore BTL propagation delays are
short. Although the voltage swing is much less for BTL, so is its receiver
threshold region, therefore noise margins are excellent.
BTL offers low power consumption, low ground bounce, reduced EMI and
crosstalk, low capacitive loading, superior noise margin and short propaga-
tion delays. This results in a high bandwidth, reliable backplane.
The MC74F3893A has four TTL outputs (Rn) on the receiver side with a
common Receive Enable input (RE). It has four data inputs (Dn) which are also
TTL. These data inputs are NANDed with the Data Enable input (DE). The four
I/O pins (Bus side) are futurebus compatible, sink a minimum of 100 mA, and
are designed to drive heavily loaded backplanes with load impedances as low
as 10 ohms. All outputs are designed to be glitch-free during power up and
power down.
Quad Backplane Transceiver
Drives Heavily Loaded Backplanes with Equivalent Load Impedances
Down to 10 ohms
Futurebus Drivers Sink 100 mA
Reduced Voltage Swing (1 Volt) Produces Less Noise and Reduces
Power Consumption
High Speed Operation Enhances Performance of Backplane Buses
and Facilitates Incident Wave Switching
Compatible with IEEE 896 and IEEE 1194.1 Futurebus Standards
Built-In Precision Band-Gap (BG) Reference Provides Accurate Re-
ceiver Threshold and Improved Noise Immunity
Glitch-Free Power Up/Power Down Operation On All Outputs
Pin and Function Compatible with NSC DS3893A and Signetics
74F3893
Separate Bus Ground Returns for Each Driver to Minimize Ground
Noise
MOS and TTL Compatible High Impedance Inputs
PINOUT: 20-LEAD PLCC (TOP VIEW)
20
19
18
17
16
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
I/O0
I/O1
I/O2
I/O3
BUS
GND
BUS
GND
BUS
GND
BG
GND
LOGIC
GND
VCC
D0
D1
D2
D3
R0
R1
R2
R3
DE
RE
MC74F3893A
QUAD FUTUREBUS
BACKPLANE TRANSCEIVER
(3 STATE + OPEN COLLECTOR)
FAST
SCHOTTKY TTL
FN SUFFIX
PLASTIC
CASE 775-02
ORDERING INFORMATION
MC74FXXXXAFN
Plastic
19
3
4
8
I/O0
I/O1
I/O2
I/O3
D0
D1
D2
D3
R0
R1
R2
R3
DE
RE
2
4
7
9
11
12
LOGIC SYMBOL
18
17
15
14
3
5
8
10