TFBS6711-TR3 Vishay, TFBS6711-TR3 Datasheet - Page 6

• Manufacturer Part Number: TFBS6711-TR3
• Description: Infrared Transceivers FIR 4Mbit/s 2.4-3.6V Op Voltage
• Manufacturer: Vishay

Specifications of TFBS6711-TR3

• Wavelength: 900 nm
• Continual Data Transmission: 4 Mbit/s
• Transmission Distance: 50 cm
• Radiant Intensity: 115 mW/sr
• Half Intensity Angle Degrees: 48 deg
• Pulse Width: 1.8 us
• Maximum Rise Time: 50 ns, 40 ns
• Maximum Fall Time: 50 ns, 40 ns
• Led Supply Voltage: - 0.5 V to 6.5 V
• Operating Voltage: 2.4 V to 3.6 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 25 C
• Data Rate Max: 4Mbps
• Data Transmission Distance: 50cm
• Peak Wavelength: 900nm
• Supply Current: 1.9mA
• Supply Voltage Range: 2.4V To 3.6V
• Operating Temperature Range: -25°C To +85°C
• Power Dissipation Pd: 500mW
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

TFBS6711
Vishay Semiconductors
RECOMMENDED CIRCUIT DIAGRAM
Operated at a clean low impedance power supply the
TFBS6711 needs no additional external components.
However, depending on the entire system design and board
layout, additional components may be required (see fig. 3).
The capacitor C1 is buffering the supply voltage and
eliminates the inductance of the power supply line. This one
should be a tantalum or other fast capacitor to guarantee the
fast rise time of the IRED current.
Vishay transceivers integrate a sensitive receiver and a
built-in power driver. The combination of both needs a
careful circuit board layout. The use of thin, long, resistive
and inductive wiring should be avoided. The inputs (RXD,
SD) and the output RXD should be directly (DC) coupled to
the I/O circuit.
The capacitor C2 combined with the resistor R2 is the low
pass filter for smoothing the supply voltage.
R2, C1 and C2 are optional and dependent on the quality of
the supply voltages V
power supply with dropping voltage during transmission may
reduce the sensitivity (and transmission range) of the
transceiver.
The placement of these parts is critical. It is strongly
recommended to position C2 as close as possible to the
transceiver power supply pins.
A tantalum capacitor should be used for C1 while a ceramic
capacitor is used for C2.
In addition, when connecting the described circuit to the
power supply, low impedance wiring should be used.
When extended wiring is used the inductance of the power
supply can cause dynamically a voltage drop at V
some power supplies are not able to follow the fast current
rise time. In that case another 4.7 µF (type, see table under
C1) at V
Keep in mind that basic RF-design rules for circuit design
should be taken into account. Especially longer signal lines
should not be used without termination. See e.g. “The Art of
Electronics” Paul Horo-witz, Winfield Hill, 1989, Cambridge
University Press, ISBN: 0521370957.
www.vishay.com
6
19299
S D
TXD
RXD
CC2
V
V
GND
CC2
CC1
Fig. 3 - Recommended Application Circuit
will be helpful.
C1
R2
CCx
C3
R1
[e-mail], [e-mail],
and injected noise. An unstable
For technical questions within your region, please contact one of the following:
C2
SD
TXD
RXD
IRED anode
V
Ground
Low Profile Fast Infrared Transceiver (FIR, 4 Mbit/s)
CC
CC2
. Often
for IrDA
I/O AND SOFTWARE
In the description, already different I/Os are mentioned.
Different combinations are tested and the function verified
with the special drivers available from the I/O suppliers. In
special cases refer to the I/O manual, the Vishay application
notes, or contact directly Vishay Sales, Marketing or
Application.
MODE SWITCHING
The TFBS6711 is in the SIR mode after power on as a
default mode, therefore the FIR data transfer rate has to be
set by a programming sequence using the TXD and SD
inputs as described below. The low frequency mode covers
speeds up to 115.2 kbit/s. Signals with higher data rates
should be detected in the high frequency mode. Lower
frequency data can also be received in the high frequency
mode but with reduced sensitivity. To switch the transceivers
from low frequency mode to the high frequency mode and
vice versa, the programming sequences described below are
required.
SETTING TO THE HIGH BANDWIDTH MODE
(0.576 Mbit/s to 4 Mbit/s)
1. Set SD input to logic “high”.
2. Set TXD input to logic “high”. Wait t
3. Set SD to logic “low” (this negative edge latches state of
4. After waiting t
TXD is now enabled as normal TXD input for the high
bandwidth mode.
TABLE 1 - RECOMMENDED APPLICATION
CIRCUIT COMPONENTS
®
COMPONENT
TXD, which determines speed setting).
hold time of TXD is limited by the maximum allowed pulse
length.
Applications
C1
C2
R1
R2
[e-mail]
h
≥ 200 ns TXD can be set to logic “low”. The
necessary, the internal controller is able to
3.3 V supply voltage: no resistor is
RECOMMENDED VALUE
VJ1206 Y 104 J XXMT
293D 475X9 016B
control the current
0.1 µF, ceramic
4.7 Ω, 0.125 W
Vishay part#:
Vishay part#:
4.7 µF, 16 V
Document Number: 84676
s
≥ 200 ns.
Rev. 1.7, 17-Sep-09