TFDU4100-TT3 Vishay, TFDU4100-TT3 Datasheet - Page 6

• Manufacturer Part Number: TFDU4100-TT3
• Description: Infrared Transceivers SIR 115.2kbits TOP VIEW
• Manufacturer: Vishay

Specifications of TFDU4100-TT3

• Wavelength: 900 nm
• Continual Data Transmission: 115.2 Kbit/s
• Radiant Intensity: 140 mW/sr
• Half Intensity Angle Degrees: 48 deg
• Pulse Width: 4 us
• Maximum Rise Time: 200 ns, 600 ns
• Maximum Fall Time: 200 ns, 600 ns
• Led Supply Voltage: - 0.5 V to 6 V
• Maximum Forward Current: 100 mA
• Operating Voltage: 2 V to 5.5 V
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 25 C
• Dimensions: 9.7 mm x 4.7 mm x 4 mm
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

unstable power supply with dropping voltage during
transmission may reduce sensitivity (and transmission
range) of the transceiver.
Table 1. Recommended Application Circuit Components
The sensitivity control (SC) pin allows the minimum
detection irradiance threshold of the transceiver to be
lowered when set to a logic HIGH.
irradiance threshold increases the sensitivity to infrared
signals and increases transmission range up to 3 meters.
However, setting the SC pin to logic HIGH also makes
the transceiver more susceptible to transmission errors
due to an increased sensitivity to fluorescent light
distrubances. It is recommended to set the SC pin to logic
LOW or left open if the increased range is not required or
if the system will be operating in bright ambient light.
The guide pins on the side-view and top-view packages
are internally connected to ground but should not be
connected to the system ground to avoid ground loops.
They should be used for mechanical purposes only and
should be left floating.
TFDU4100/TFDS4500/TFDT4500
6
Component
300
250
200
150
100
C1
C2
R1
R2
50
0
4.0
IrDA Field of View: Cone of "15_
100 nF, Ceramic (use 470 nF for less stable power
supplies)
1 F, Tantalum
8.2 , 0.25 W (recommend using two 0.125 W
resistors in parallel)
22 – 47 , 0.125 W
6.0
Current Control Resistor, R
Figure 2. I
8.0
Recommended Value
4.75 V, Min. Efficiency,
Min. VF, Max. R
10.0
5.25 V, Min. Efficiency,
Min. VF, Min. R
e
Pre-Release Information
vs R
12.0
l
DSon
l
Lowering the
(W)
14.0
DSon
16.0
Shutdown
The internal switch for the IRED in TEMIC SIR
transceivers is designed to be operated like an open
collector driver.
unregulated power supply while only a well regulated
power source with a supply current of 1.3 mA connected
to V
of the transceiver circuitry in receive mode. In transmit
mode, this current is slightly higher (approxiamately 4
mA average at 3V supply current) and the voltage is not
required to be kept as stable as in receive mode. A voltage
drop of V
buffering the voltage directly from the V
by a 470 nF ceramic capacitor (C1) and a 51
resistor (R2) is used (see figure 1).
This configuration minimizes the influence of high
current surges from the IRED on the internal analog
control circuitry of the transceiver and the application
circuit.
achieved by eliminating the additional linear regulator
normally
requirements.
The transceiver can be very efficiently shutdown by
keeping the IRED connected to the power supply V
but switching off V
V
(see Figure 3). In shutdown, current loss is realized only
as leakage current through the current limiting resistor to
the IRED (typically, 5 nA).
switching V
TEMIC’s TOIM3232 interface circuit is designed for this
shutdown feature. The V
TOIM3232 can be used to power the transceiver with the
necessary supply current.
If the microcontroller or the microprocessor is unable to
drive the 1.3-mA supply current required by the
transceiver, a low-cost SOT-23 pnp transistor can be used
to switch voltage on and off from the regulated power
supply (see figure 4). The additional component cost is
minimal and saves the system designer additional power
supply costs.
CC1
CC1
/SD can be provided directly from a microcontroller
/SD is needed to provide power to the remainder
Also, board space and cost savings can be
CC1
needed
CC1
is acceptable down to about 2.2V when
/SD on again is approxiamately 50 s.
Thus, the V
for
CC1
cc
/SD. The power source to
Pending—Rev. A, 03-Apr-98
the
_SD, S0 or S1 outputs on the
TELEFUNKEN
IRED’s
The settling time after
CC2
Semiconductor
source can be an
CC1
high
pin to GND
current
serial
CC2