tfdu6301 Vishay, tfdu6301 Datasheet - Page 8

• Manufacturer Part Number: tfdu6301
• Description: Fast Infrared Transceiver Module Fir, 4 Mbit/s For 2.4 V To 3.6 V Operation And Low
• Manufacturer: Vishay

TFDU6301
Vishay Semiconductors
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 TFDU6301 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 TXD, which determines speed setting).
4. After waiting t
"Low". The hold time of TXD is limited by the
maximum allowed pulse length.
Table 2.
Truth table
www.vishay.com
8
High
Low
SD
High > 100 µs
h
High
≥ 200 ns TXD can be set to logic
TXD
Low
Low
Low
x
Inputs
< Max. detection threshold irradiance
> Max. detection threshold irradiance
> Min. detection threshold irradiance
Optical input Irradiance mW/m
s
≥ 200 ns.
< 4
x
x
x
TXD is now enabled as normal TXD input for the high
bandwidth mode.
Setting to the Lower Bandwidth Mode
(2.4 kbit/s to 115.2 kbit/s)
1. Set SD input to logic "High".
2. Set TXD input to logic "Low". Wait t
3. Set SD to logic "Low" (this negative edge latches
state of TXD, which determines speed setting).
4. TXD must be held for t
TXD is now enabled as normal TXD input for the
lower bandwidth mode.
SD
TXD
2
Figure 4. Mode Switching Timing Diagram
50 %
(500 kΩ) to V
weakly pulled
Low (active)
Low (echo)
t
s
RXD
High
High
h
x
≥ 200 ns.
50 %
t
Outputs
h
CC1
Document Number 84668
50 %
Rev. 1.7, 03-Jan-08
s
High: FIR
≥ 200 ns.
Low: SIR
Transmitter
I
0
0
0
0
0
e
14873