• Three separate pairs of driver enables in a 1 bit, 3 bit, 3 bit
arrangement
• 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
current
CC
• Tight output skew
• Supports live insertion
• Pins for the optional JTAG boundary scan function are provided
• High density packaging in plastic Quad Flatpack
• 5V compatible I/O on A-port
• Industrial temperature range option available as FBL2041I
DESCRIPTION
The FBL2041/FBL2041I is a 7-bit bidirectional BTL transceiver and
is intended to provide the electrical interface to a high performance
wired-OR bus. The FBL2041 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 FBL2041/FBL2041I is pin and function compatible with FB2041
but operates at a 3.3V supply voltage, greatly reducing power
consumption.
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.
There are three separate pairs of driver enables in a 1 bit, 3 bit, 3 bit
arrangement. The TTL/BTL output drivers for bit 0 are enabled with
OEA1/OEB1
OEA2/OEB2
OEA3/OEB3
The A-port operates at TTL levels with separate I/O. The 3-state
A-port drivers are enabled when OEAn goes High after an extra 6ns
delay which is built in to provide a break-before-make function.
When OEAn 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
The B-port has an output enable, OEB0, which affects all seven
drivers. When OEB0 is High and OEBn
be enabled. When OEB0 is Low or if OEBn
drivers will be inactive and 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
3.3V level while V
BIAS V pin should be tied to a V
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.
JTAG boundary scan functionality is provided as an option with
signals TMS, TCK, TDI and TDO. When this option is not present,
TMS and TCK are no-connects (no bond wires) and TDI and TDO
are shorted together internally.
, output drivers for bits 1–2–3 are enabled with
and output drivers for bits 4–5–6 are enabled with
.
is Low. If live insertion is not a requirement, the
B0 – B640, 38, 36, 34, 32, 30, 28I/OData inputs/Open Collector outputs, High current drive (BTL)
OEB046InputEnables the Bn outputs when High
OEB145InputEnables the B0 output when Low
OEB225InputEnables the B1 – B3 outputs when Low
OEB326InputEnables the B4 – B6 outputs when Low
OEA147InputEnables the A0 outputs when High
OEA220InputEnables the A1 – A3 outputs when High
OEA324InputEnables the A4 – A6 outputs when High
BUS GND41, 39, 37, 35, 33, 31, 29GNDBus ground (0V)
H=High voltage level
L=Low voltage level
X=Don’t care
Z=High-impedance (OFF) state
— =Input not externally driven
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.
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.
SYMBOLPARAMETERRATINGUNIT
V
CC
I
IN
V
OUT
OUT
T
STG
RECOMMENDED OPERATING CONDITIONS
SYMBOLPARAMETER
V
CC
I
IK
I
OH
C
OB
T
amb
Supply voltage–0.5 to +4.6V
p
AI0 – AI6, OEB0, OEBn, OEAn–0.5 to +7.0
B0 – B6–0.5 to +3.5
Input currentVIN t 0–50
Voltage applied to output in High output state–0.5 to +7.0V
Current applied to output in
Low output state/High output state
RL= Load Resistor; see AC CHARACTERISTICS for value.
CL= Load capacitance includes jig and probe capacitance; see AC
CHARACTERISTICS for value.
R
= Termination resistance should be equal to Z
T
CD= Load capacitance includes jig and probe capacitance; see AC
CHARACTERISTICS for value.
RU= Pull up resistor; see AC CHARACTERISTICS for value.
t
W
(tf)
t
THL
t
(tr)
TLH
t
W
Input Pulse Definitions
Rep. RateAmplitudet
0.0V
1.0VB Port
1MHz3.0V
1MHz2.0V
FBL2041
FBL2041I
90%
V
M
10%
90%
V
M
10%
t
TLHtTHL
W
2.5ns
500ns
2.5ns500ns
of pulse generators.
OUT
t
t
TLH
THL
V
IN
LOW V
(tr)
(tf)
V
IN
LOW V
2.5ns
2.5ns
SG00090
1999 Apr 27
10
Page 11
Philips SemiconductorsProduct specification
3.3V BTL 7-bit Futurebus+ transceiver (standard A port)
FBL2041
FBL2041I
QFP52: plastic quad flat package; 52 leads (lead length 1.6 mm); body 10 x 10 x 2.0 mmSOT379-1
1999 Apr 27
11
Page 12
Philips SemiconductorsProduct specification
3.3V BTL 7-bit Futurebus+ transceiver (standard A port)
Data sheet status
Data sheet
status
Objective
specification
Preliminary
specification
Product
specification
Product
status
Development
Qualification
Production
Definition
This data sheet contains the design target or goal specifications for product development.
Specification may change in any manner without notice.
This data sheet contains preliminary data, and supplementary data will be published at a later date.
Philips Semiconductors reserves the right to make changes at any time without notice in order to
improve design and supply the best possible product.
This data sheet contains final specifications. Philips Semiconductors reserves the right to make
changes at any time without notice in order to improve design and supply the best possible product.
[1]
FBL2041
FBL2041I
[1] Please consult the most recently issued datasheet before initiating or completing a design.
Definitions
Short-form specification — The data in a short-form specification is extracted from a full data sheet with the same type number and title. For
detailed information see the relevant data sheet or data handbook.
Limiting values definition — Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 134). Stress above one
or more of the limiting values may cause permanent damage to the device. These are stress ratings only and operation of the device at these or
at any other conditions above those given in the Characteristics sections of the specification is not implied. Exposure to limiting values for extended
periods may affect device reliability.
Application information — Applications that are described herein for any of these products are for illustrative purposes only. Philips
Semiconductors make no representation or warranty that such applications will be suitable for the specified use without further testing or
modification.
Disclaimers
Life support — These products are not designed for use in life support appliances, devices or systems where malfunction of these products can
reasonably be expected to result in personal injury . Philips Semiconductors customers using or selling these products for use in such applications
do so at their own risk and agree to fully indemnify Philips Semiconductors for any damages resulting from such application.
Right to make changes — Philips Semiconductors reserves the right to make changes, without notice, in the products, including circuits, standard
cells, and/or software, described or contained herein in order to improve design and/or performance. Philips Semiconductors assumes no
responsibility or liability for the use of any of these products, conveys no license or title under any patent, copyright, or mask work right to these
products, and makes no representations or warranties that these products are free from patent, copyright, or mask work right infringement, unless
otherwise specified.
Philips Semiconductors
811 East Arques Avenue
P.O. Box 3409
Sunnyvale, California 94088–3409
Telephone 800-234-7381
Copyright Philips Electronics North America Corporation 1999
All rights reserved. Printed in U.S.A.
Date of release: 11-99
Document order number:9397 750 06597
1999 Apr 27
12
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