
Philips Semiconductors Product specification
FB2040A8-bit Futurebus+ transceiver
1
1995 May 25 853-1801 15279
FEATURES
•8-bit BTL transceivers
•Separate I/O on TTL A-port
•Inverting
•Drives heavily loaded backplanes with equivalent load
impedances down to 10Ω.
•High drive 100mA BTL open collector drivers on B-port
•Allows incident wave switching in heavily loaded backplane buses
•Reduced BTL voltage swing produces less noise and reduces
power consumption
•Built-in precision band-gap reference provides accurate receiver
thresholds and improved noise immunity
•Compatible with IEEE Futurebus+ or proprietary BTL backplanes
•Controlled output ramp and multiple GND pins minimize ground
bounce
•Each BTL driver has a dedicated Bus GND for a signal return
•Glitch-free power up/power down operation
•Low I
CC
current
•Tight output skew
•Supports live insertion
•Pins for the optional JTAG boundary scan function are provided
•High density packaging in plastic Quad Flat Pack
QUICK REFERENCE DATA
SYMBOL PARAMETER TYPICAL UNIT
t
PLH
t
PHL
Propagation delay
AIn to Bn
4.4
3.1
ns
t
PLH
t
PHL
Propagation delay
Bn
to AOn
3.4
3.2
ns
C
OB
Output capacitance (B0 – B7 only) 4 pF
I
OL
Output current (B0 – B7 only) 100 mA
AIn to Bn
(outputs Low or High)
4
Bn to AOn
(outputs Low)
22
Bn to AOn
(outputs High)
12
ORDERING INFORMATION
PACKAGES
COMMERCIAL RANGE
V
CC
= 5V±10%; T
amb
= 0°C to +70°C
DRAWING
NUMBER
52-pin Plastic Quad Flat Pack (QFP) FB2040BB SOT379-1
ABSOLUTE MAXIMUM RATINGS
Operation beyond the limits set forth in this table may impair the useful life of the device. Unless otherwise noted these limits are over the
operating free-air temperature range.
SYMBOL
PARAMETER RATING UNIT
V
CC
Supply voltage -0.5 to +7.0 V
AI0 – AI7, OEB0, OEB1, OEA -1.2 to +7.0
I
IN
Input current -18 to +5.0 mA
V
OUT
Voltage applied to output in High output state -0.5 to +V
CC
V
Current applied to output in Low
output state
T
amb
Operating free-air temperature range -40 to ++85 °C
T
STG
Storage temperature -65 to +150 °C
I
CC
Supply current
mA
Current applied to output in Low

Philips Semiconductors Product specification
FB2040A8-bit Futurebus+ transceiver
1995 May 25
2
PIN CONFIGURATION
52 51 50 49 48 47 46 45 44 43 42 41 40
39
38
37
36
35
34
33
32
31
30
29
28
27
1
2
3
4
5
6
7
8
9
10
11
12
13
14 15 16 17 18 19 20 21 22 23 24 25 26
BUS GND
B1
BUS GND
B2
BUS GND
B3
BUS GND
B4
BUS GND
B5
BUS GND
B6
BUS GND
LOGIC GND
AI1
AI2
AO2
LOGIC GND
AO3
LOGIC GND
AI3
AI4
AO4
LOGIC GND
AO5
LOGIC GND
AI5
LOGIC GND
AO6
BG GND
TDO (option)
TDI (option)
AI6
B7
BUS V
CC
BG V
CC
AO1
AO0
OEA
TCK (option)
TMS (option)
BUS GND
OEB1
BIAS V
B0/B0
BUS V
CC
LOGIC V
CC
OEB0
8-Bit Transceiver
FB2040A
52-lead PQFP
AI0
NC
AI7
AO7
SG00076
DESCRIPTION
The FB2040A is an 8-bit bidirectional BTL transceiver and is
intended to provide the electrical interface to a high performance
wired-OR bus. The FB2040A is an inverting transceiver.
The B-port drivers are Low-capacitance open collectors with
controlled ramp and are designed to sink 100mA. Precision band
gap references on the B-port insure very good noise margins by
limiting the switching threshold to a narrow region centered at 1.55V .
The B-port interfaces to “Backplane Transceiver Logic” (See the
IEEE 1194.1 BTL standard). BTL features low power consumption
by reducing voltage swing (1Vp-p, between 1V and 2V) and reduced
capacitive loading by placing an internal series diode on the drivers.
BTL also provides incident wave switching, a necessity for high
performance backplanes.
The A-port operates at TTL levels with separate I/O. The 3-state
A-port drivers are enabled when OEA goes High after an extra 6ns
delay which is built in to provide a break-before-make function.
When OEA goes Low, A-port drivers become High impedance
without any extra delay. During power on/of f cycles, the A-port
drivers are held in a High impedance state when V
CC
is below 2.5V.
The B-port has two output enables, OEB0 and OEB1
. When OEB0
is High and OEB1
is Low the output is enabled. When OEB0 is Low
or if OEB1
is High, the B-port is inactive and is at the level of the
backplane signal.
To support live insertion, OEB0 is held Low during power on/off
cycles to insure glitch free B port drivers. Proper bias for B port
drivers during live insertion is provided by the BIAS V pin when at a
5V level while V
CC
is Low. If live insertion is not a requirement, the
BIAS V pin should be tied to a V
CC
pin.
The LOGIC GND and BUS GND pins are isolated in the package to
minimize noise coupling between the BTL and TTL sides. These
pins should be tied to a common ground external to the package.
Each BTL driver has an associated BUS GND pin that acts as a
signal return path and these BUS GND pins are internally isolated
from each other. In the event of a ground return fault, a “hard” signal
failure occurs instead of a pattern dependent error that may be very
infrequent and impossible to trouble-shoot.
The LOGIC V
CC
and BUS VCC pins are also isolated internally to
minimize noise and may be externally decoupled separately or
simply tied together.
JTAG boundary scan pins are provided with signals TMS, TCK, TDI
and TDO. TMS and TCK are no-connects (no bond wires) and TDI
and TDO are shorted together internally. Boundary scan
functionality is not implemented at this time.

Philips Semiconductors Product specification
FB2040A8-bit Futurebus+ transceiver
1995 May 25
3
PIN DESCRIPTION
SYMBOL PIN NUMBER TYPE NAME AND FUNCTION
AI0 – AI7 51, 2, 3, 8, 9, 14, 18, 24 Input Data inputs (TTL)
AO0 – AO7 50, 52, 4, 6, 10, 12, 16, 20 Output 3-state outputs (TTL)
B0 – B7
40, 38, 36, 34,
32, 30, 28, 26
I/O Data inputs/Open Collector outputs. High current drive (BTL)
OEB0 46 Input Enables the B outputs when High
OEB1 45 Input Enables the B outputs when Low
OEA 47 Input Enables the A outputs when High
BUS GND 41, 39, 37, 35, 33, 31, 29, 27 GND Bus ground (0V)
LOGIC GND 1, 5, 7, 11, 13, 15 GND Logic ground (0V)
BUS V
CC
23, 43 Power Positive supply voltage
LOGIC V
CC
49 Power Positive supply voltage
BG V
CC
17 Power Band Gap threshold voltage reference
BG GND 19 GND Band Gap threshold voltage reference ground
BIAS V 48 Power Live insertion pre-bias pin
TMS 42 Input Test Mode Select (optional, if not implemented then no-connect)
TCK 44 Input Test Clock (optional, if not implemented then no-connect)
TDI 22 Input Test Data In (optional, if not implemented then shorted to TDO)
TDO 21 Output Test Data Out (optional, if not implemented then shorted to TDI)
NC 25 NC No Connect
FUNCTION TABLE
AIn Bn* OEB0 OEB1 OEA AOn Bn*
L — H L H L H**
H — H L H H L
X X X H X X H**
X L L X H H Input
X H X H H L Input
X H L X H L Input
Disable AOn outputs — X X X L Z X
H** = Goes to level of pull-up voltage
B* = Precaution should be taken to ensure B inputs do not float. If they do, they are equal to Low state.

Philips Semiconductors Product specification
FB2040A8-bit Futurebus+ transceiver
1995 May 25
4
RECOMMENDED OPERATING CONDITIONS
V
CC
Supply voltage 4.5 5.0 5.5 V
I
IK
Input clamp current -18 mA
I
OH
High-level output current AO0 – AO7 -3 mA
C
OB
Output capacitance on B port 5 pF
T
amb
Operating free-air temperature range 0 +70 °C

Philips Semiconductors Product specification
FB2040A8-bit Futurebus+ transceiver
1995 May 25
5
LOGIC DIAGRAM FOR FB2040
46
45
OEB0
OEB1
47
OEA
BTL
Levels
TTL
Levels
TMS
TCK
TDI
TDO
42
44
22
21
(Future JTAG Boundary Scan option)
NC = 25
LOGIC V
CC
= 49
LOGIC GND = 1, 5, 7, 11, 13, 15
BUS V
CC
= 23, 43
BUS GND = 27, 29, 31, 33, 35, 37, 39, 41
BIAS V = 48
BG V
CC
= 17
BG GND = 19
51
AI0
50
AO0
B0
40
38
B1
2
52
AI1
AO1
36
3
4
B2
AI2
AO2
34
8
6
B3
AI3
AO3
32
9
10
30
14
12
28
18
16
B4
AI4
AO4
B5
AI5
AO5
B6
AI6
AO6
26
24
20
B7
AI7
AO7
SG00077

Philips Semiconductors Product specification
FB2040A8-bit Futurebus+ transceiver
1995 May 25
6
DC ELECTRICAL CHARACTERISTICS
Over recommended operating free-air temperature range unless otherwise noted.
I
OH
High level output current B0 – B7 VCC = MAX, VIL = MAX, VIH = MIN, VOH = 2.1V 100 µA
I
OFF
Power-off output current B0 – B7 VCC = 0.0V, VIL = MAX, VIH = MIN, VOH = 2.1V 100 µA
V
OH
High-level output voltage AO0 – AO73VCC = MIN, VIL = MAX, VIH = MIN, IOH = -3mA 2.5 2.85 V
AO0 – AO73VCC = MIN, VIL = MAX, VIH = MIN, IOL = 24mA 0.33 0.5
VCC = MIN, VIL = MAX, VIH = MIN, IOL = 80mA .75 1.0 1.10
VCC = MIN, VIL = MAX, VIH = MIN, IOL = 100mA 1.15
V
IK
Input clamp voltage VCC = MIN, II = I
IK
-1.2 V
I
I
Input current at maximum
input voltage
OEB0, OEB1,
OEA, AI0–AI7
VCC = MAX, VI = GND or 5.5V ±50 µA
OEB0, OEB1,
OEA, AI0–AI7
VCC = MAX, VI = 2.7V 20
IIHHigh-level input current
B0 – B7 VCC = MAX, VI = 2.1V 100
OEB0, OEB1,
OEA, AI0–AI7
VCC = MAX, VI = 0.5V -20
IILLow-level input current
B0 – B7 VCC = MAX, VI = 0.75V -100
I
OZH
Off-state output current AO0 – AO7 VCC = MAX, VO = 2.7V 50 µA
I
OZL
Off-state output current AO0 – AO7 VCC = MAX, VO = 0.5V -50 µA
I
OS
Short-circuit output
current
4
AO0 – AO7
only
VCC = MAX, VO = 0.0V -30 -150 mA
I
CCZ
(standby) VCC = MAX 19 30
I
CCB,
AIn to
Bn
VCC = MAX, outputs Low or High 40 60
I
CCA,
Bn to
AOn
VCC = MAX, outputs Low 22 35
I
CCA,
Bn to
AOn
VCC = MAX, outputs High 19 35
NOTES:
1. For conditions shown as MIN or MAX, use the appropriate value specified under recommended operation conditions for the applicable type.
2. All typical values are at V
CC
= 5V, TA = 25°C.
3. Due to test equipment limitations, actual test conditions are V
IH
= 1.8V and VIL = 1.3V for the B side.
4. Not more than one output should be shorted at a time. For testing I
OS
, the use of high-speed test apparatus and/or sample-and-hold
techniques are preferable in order to minimize internal heating and more accurately reflect operational values. Otherwise, prolonged
shorting of a High output may raise the chip temperature well above normal and thereby cause invalid readings in other parameter tests. In
any sequence of parameter tests, I
OS
should be performed last.
V
I
CC
Low-level output voltage
OL
Supply current (total)
V
mA

Philips Semiconductors Product specification
FB2040A8-bit Futurebus+ transceiver
1995 May 25
7
AC ELECTRICAL CHARACTERISTICS
T
amb
= +25°C, VCC = 5V,
C
L
= 50pF, RL = 500Ω
T
amb
= 0 to 70°C,
V
CC
= 5V±10%,
CL = 50pF, RL = 500Ω
MIN TYP MAX MIN MAX
t
PLH
t
PHL
Propagation delay,
Bn
to AOn
Waveform 1, 2
1.8
1.6
3.4
3.2
5.0
4.9
1.6
1.6
5.6
5.3
ns
t
PZH
t
PZL
Output enable time,
OEA to AOn
Waveform 4, 5
1.0
1.0
5.0
5.0
1.5
1.5
5.5
5.5
ns
t
PHZ
t
PLZ
Output disable time,
OEA to AOn
Waveform 4, 5
1.5
1.5
3.3
3.3
4.8
5.4
1.2
1.3
5.0
5.9
ns
t
TLH
t
THL
Transition time, AOn Port
(10% to 90% or 90% to 10%)
Test Circuit and
Waveforms
1.5
1.5
2.2
2.4
3.5
3.5
1.0
1.0
4.5
4.5
ns
tSK(o)
Output skew between receivers
in same package
1
Waveform 3 0.4 1.0 1.0 ns
TEST CONDITION
T
amb
= +25°C, VCC = 5V,
C
D
= 30pF, RU = 9Ω
T
amb
= 0 to 70°C,
V
CC
= 5V±10%,
CD = 30pF, RU = 9Ω
t
PLH
t
PHL
Propagation delay,
AIn to Bn
Waveform 1, 2
2.9
1.6
4.4
3.3
5.0
4.8
2.3
1.5
5.5
5.1
ns
t
PLH
t
PHL
Enable/disable time,
OEB0 to Bn
Waveform 2
2.9
1.9
4.7
3.5
5.9
5.1
2.6
1.8
7.8
5.7
ns
t
PLH
t
PHL
Enable/disable time,
OEB1
to Bn
Waveform 1
3.0
1.7
5.3
3.2
6.3
4.8
2.7
1.5
8.0
5.7
ns
t
TLH
t
THL
Transition time, Bn Port
(1.3V to 1.8V)
Test Circuit and
Waveforms
1.0
0.5
1.4
1.1
3.0
3.0
1.0
0.5
3.0
3.0
ns
tSK(o)
Output skew between drivers in
same package
1
Waveform 3 0.3 1.0 1.0 ns
SYMBOL PARAMETER TEST CONDITION RU = 16.5Ω RU = 16.5Ω UNIT
t
PLH
t
PHL
Propagation delay,
AIn to Bn
Waveform 1, 2
3.0
1.7
4.5
3.3
6.4
4.8
2.3
1.6
6.9
5.1
ns
t
PLH
t
PHL
Enable/disable time,
OEB0 to Bn
Waveform 2
3.0
2.0
4.8
3.5
6.0
5.2
2.7
1.9
7.9
5.7
ns
t
PLH
t
PHL
Enable/disable time,
OEB1
to Bn
Waveform 1
3.1
1.8
5.4
3.3
6.4
4.9
2.8
1.6
8.1
5.7
ns
t
TLH
t
THL
Transition time, Bn Port
(1.3V to 1.8V)
Test Circuit and
Waveforms
1.0
0.5
1.5
1.1
3.0
3.0
1.0
0.5
3.0
3.0
ns
tSK(o)
Output skew between drivers in
same package
1
Waveform 3 0.3 1.0 1.0 ns
NOTES:
1. t
PN
actual – tPMactual for any data input to output path compared to any other data input to output path where N and M are either LH or
HL. Skew times are valid only under same test conditions (temperature, V
CC
, loading, etc.).

Philips Semiconductors Product specification
FB2040A8-bit Futurebus+ transceiver
1995 May 25
8
AC WAVEFORMS
t
PZL
AIn, Bn
OEB1
AOn, Bn
V
M
V
M
V
M
V
M
t
PLH
t
PHL
V
M
V
M
V
M
V
M
t
PHL
t
PLH
AOn, Bn
AIn, Bn
AOn, Bn
V
M
V
M
tSK(o)
AOn
OEA
V
M
V
M
t
PLZ
V
M
VOL +0.3V
AOn
OEA
V
M
V
M
V
M
VOH -0.3V
OV
t
PHZ
t
PZH
NOTE: V
M
= 1.55V for Bn, V
M
= 1.5V for all others.
AIn, Bn
OEB0
Waveform 1. Propagation Delay for Data
or Output Enable to Output
Waveform 2. Propagation Delay for Data
or Output Enable to Output
Waveform 3. Output Skews
Waveform 4. 3-State Output Enable Time to High Level
and Output Disable Time from High Level
Waveform 5. 3-State Output Enable Time to Low Level
and Output Disable Time from Low Level
SG00078

Philips Semiconductors Product specification
FB2040A8-bit Futurebus+ transceiver
1995 May 25
9
TEST CIRCUIT AND WAVEFORMS
2.5ns
2.5ns500ns
500ns
INPUT PULSE REQUIREMENTS
Rep. RateAmplitude t
TLHtTHL
1MHz3.0V
2.5ns
Input Pulse Definitions
VM = 1.55V for Bn, VM = 1.5V for all others.
V
CC
Family
FB+
D.U.T.
PULSE
GENERATOR
7.0V
R
L
R
L
C
L
R
T
V
IN
V
OUT
Test Circuit for 3-State Outputs on A Port
TEST SWITCH
SWITCH POSITION
t
PLZ,
t
PZL
All other
closed
open
DEFINITIONS:
R
L
= Load Resistor; see AC CHARACTERISTICS for value.
C
L
= Load capacitance includes jig and probe capacitance; see AC
CHARACTERISTICS for value.
R
T
= Termination resistance should be equal to Z
OUT
of pulse generators.
CD= Load capacitance includes jig and probe capacitance; see AC
CHARACTERISTICS for value.
R
U
= Pull up resistor; see AC CHARACTERISTICS for value.
t
W
90%
V
M
10%
90%
V
M
10%
90%
V
M
10%
90%
V
M
10%
NEGATIVE
PULSE
POSITIVE
PULSE
AMP (V)
LOW V
LOW V
t
THL
(tf)
t
TLH
(tr)
t
W
BIAS
V
t
W
Low V
0.0V
t
TLH
(tr)
t
THL
(tf)
AMP (V)
A Port
1MHz2.0V
2.5ns
1.0VB Port
V
CC
D.U.T.
PULSE
GENERATOR
R
U
C
D
R
T
V
IN
V
OUT
Test Circuit for Outputs on B Port
BIAS
V
2.0V (for RU = 9 Ω)
2.1V (for RU = 16.5 Ω)
SG00059